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Re: [PATCH] usb: dwc2: fix the incorrect bitmaps for the ports of multi_tt hub

by Doug Anderson

Hi, On Mon, May 21, 2018 at 3:12 AM, William Wu <william.wu(a)rock-chips.com> wrote: > The dwc2_get_ls_map() use ttport to reference into the > bitmap if we're on a multi_tt hub. But the bitmaps index > from 0 to (hub->maxchild - 1), while the ttport index from > 1 to hub->maxchild. This will cause invalid memory access > when the number of ttport is hub->maxchild. > > Without this patch, I can easily meet a Kernel panic issue > if connect a low-speed USB mouse with the max port of FE2.1 > multi-tt hub (1a40:0201) on rk3288 platform. > > Signed-off-by: William Wu <william.wu(a)rock-chips.com> > --- > drivers/usb/dwc2/hcd_queue.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/dwc2/hcd_queue.c b/drivers/usb/dwc2/hcd_queue.c > index d7c3d6c..9c55d1a 100644 > --- a/drivers/usb/dwc2/hcd_queue.c > +++ b/drivers/usb/dwc2/hcd_queue.c > @@ -383,7 +383,7 @@ static unsigned long *dwc2_get_ls_map(struct dwc2_hsotg *hsotg, > /* Get the map and adjust if this is a multi_tt hub */ > map = qh->dwc_tt->periodic_bitmaps; > if (qh->dwc_tt->usb_tt->multi) > - map += DWC2_ELEMENTS_PER_LS_BITMAP * qh->ttport; > + map += DWC2_ELEMENTS_PER_LS_BITMAP * (qh->ttport - 1); Oops, thanks for the fix. Fixes: 9f9f09b048f5 ("usb: dwc2: host: Totally redo the microframe scheduler") Cc: stable(a)vger.kernel.org Reviewed-by: Douglas Anderson <dianders(a)chromium.org> -Doug

7 years, 5 months

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+ mm-devm_memremap_pages-handle-errors-allocating-final-devres-action.patch added to -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm, devm_memremap_pages: handle errors allocating final devres action has been added to the -mm tree. Its filename is mm-devm_memremap_pages-handle-errors-allocating-final-devres-action.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-devm_memremap_pages-handle-erro… and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-devm_memremap_pages-handle-erro… Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Dan Williams <dan.j.williams(a)intel.com> Subject: mm, devm_memremap_pages: handle errors allocating final devres action The last step before devm_memremap_pages() returns success is to allocate a release action to tear the entire setup down. However, the result from devm_add_action() is not checked. Checking the error also means that we need to handle the fact that the percpu_ref may not be killed by the time devm_memremap_pages_release() runs. Add a new state flag for this case. Link: http://lkml.kernel.org/r/152694212460.5484.13180030631810166467.stgit@dwill… Fixes: e8d513483300 ("memremap: change devm_memremap_pages interface...") Signed-off-by: Dan Williams <dan.j.williams(a)intel.com> Cc: Christoph Hellwig <hch(a)lst.de> Cc: "Jérôme Glisse" <jglisse(a)redhat.com> Cc: Logan Gunthorpe <logang(a)deltatee.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/memremap.h | 1 + kernel/memremap.c | 8 ++++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff -puN include/linux/memremap.h~mm-devm_memremap_pages-handle-errors-allocating-final-devres-action include/linux/memremap.h --- a/include/linux/memremap.h~mm-devm_memremap_pages-handle-errors-allocating-final-devres-action +++ a/include/linux/memremap.h @@ -115,6 +115,7 @@ struct dev_pagemap { dev_page_free_t page_free; struct vmem_altmap altmap; bool altmap_valid; + bool registered; struct resource res; struct percpu_ref *ref; struct device *dev; diff -puN kernel/memremap.c~mm-devm_memremap_pages-handle-errors-allocating-final-devres-action kernel/memremap.c --- a/kernel/memremap.c~mm-devm_memremap_pages-handle-errors-allocating-final-devres-action +++ a/kernel/memremap.c @@ -296,7 +296,7 @@ static void devm_memremap_pages_release( for_each_device_pfn(pfn, pgmap) put_page(pfn_to_page(pfn)); - if (percpu_ref_tryget_live(pgmap->ref)) { + if (pgmap->registered && percpu_ref_tryget_live(pgmap->ref)) { dev_WARN(dev, "%s: page mapping is still live!\n", __func__); percpu_ref_put(pgmap->ref); } @@ -418,7 +418,11 @@ void *devm_memremap_pages(struct device percpu_ref_get(pgmap->ref); } - devm_add_action(dev, devm_memremap_pages_release, pgmap); + error = devm_add_action_or_reset(dev, devm_memremap_pages_release, + pgmap); + if (error) + return ERR_PTR(error); + pgmap->registered = true; return __va(res->start); _ Patches currently in -mm which might be from dan.j.williams(a)intel.com are mm-devm_memremap_pages-mark-devm_memremap_pages-export_symbol_gpl.patch mm-devm_memremap_pages-handle-errors-allocating-final-devres-action.patch mm-hmm-use-devm-semantics-for-hmm_devmem_add-remove.patch mm-hmm-replace-hmm_devmem_pages_create-with-devm_memremap_pages.patch mm-hmm-mark-hmm_devmem_add-add_resource-export_symbol_gpl.patch

7 years, 5 months

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RE: [PATCH] mtd: rawnand: micron: Fix support for on-die ECC

by Bean Huo (beanhuo)

Hi, Boris Sorry for the later as for I am in a long vacation. Here how the SR should behave: the status register is updated after each array operation and can be cleared with a reset command. After a read operation the status register bit0 will report the ECC status of the read until a different array operation is performed (erase/program/read) or a reset occurs. The status register bit1 will report the status of the time before last time operation. So, this bit can report a fail (value 1) even if the very last operation was successful (bit0=0 bit1=1). //beanhuo > >--- >Peter, Bean, > >Can you confirm this behavior, or ask someone in Micron who can confirm it? >Also, if a RESET is actually needed, it would be good to update the datasheet >accordingly. And if that's not the case, can you explain why the >NAND_STATUS_FAIL bit is stuck and how to clear it (I tried a 0x00 command, >A.K.A. READ STATUS EXIT, but it does not clear this bit, ERASE and PROGRAM >seem to clear the bit, but that's clearly not the kind of operation I can do >when the user asks for a READ)? > >Thanks, > >Boris

7 years, 5 months

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[PATCH] dmaengine: ensure dmaengine helpers check valid callback

by Fabrizio Castro

From: Vinod Koul <vinod.koul(a)intel.com> commit 757d12e5849be549076901b0d33c60d5f360269c upstream. dmaengine has various device callbacks and exposes helper functions to invoke these. These helpers should check if channel, device and callback is valid or not before invoking them. Reported-by: Jon Hunter <jonathanh(a)nvidia.com> Signed-off-by: Vinod Koul <vinod.koul(a)intel.com> [fabrizio: cherry-pick to 4.4] Signed-off-by: Fabrizio Castro <fabrizio.castro(a)bp.renesas.com> Signed-off-by: Jianming Qiao <jianming.qiao(a)bp.renesas.com> --- Hello Greg, while backporting commit 757d12e5849be549076901b0d33c60d5f360269c to the CIP kernel Ben recommended to send the same patch to you for 4.4 stable. I hope the format of the commit is the one you expect (reference to the upstream commit, version to cherry-pick the patch to, and Signed-off-by tags). Thanks, Fab include/linux/dmaengine.h | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index c47c68e..a16d185 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -767,6 +767,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single( sg_dma_address(&sg) = buf; sg_dma_len(&sg) = len; + if (!chan || !chan->device || !chan->device->device_prep_slave_sg) + return NULL; + return chan->device->device_prep_slave_sg(chan, &sg, 1, dir, flags, NULL); } @@ -775,6 +778,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction dir, unsigned long flags) { + if (!chan || !chan->device || !chan->device->device_prep_slave_sg) + return NULL; + return chan->device->device_prep_slave_sg(chan, sgl, sg_len, dir, flags, NULL); } @@ -786,6 +792,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_rio_sg( enum dma_transfer_direction dir, unsigned long flags, struct rio_dma_ext *rio_ext) { + if (!chan || !chan->device || !chan->device->device_prep_slave_sg) + return NULL; + return chan->device->device_prep_slave_sg(chan, sgl, sg_len, dir, flags, rio_ext); } @@ -796,6 +805,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic( size_t period_len, enum dma_transfer_direction dir, unsigned long flags) { + if (!chan || !chan->device || !chan->device->device_prep_dma_cyclic) + return NULL; + return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len, period_len, dir, flags); } @@ -804,6 +816,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma( struct dma_chan *chan, struct dma_interleaved_template *xt, unsigned long flags) { + if (!chan || !chan->device || !chan->device->device_prep_interleaved_dma) + return NULL; + return chan->device->device_prep_interleaved_dma(chan, xt, flags); } @@ -811,7 +826,7 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_memset( struct dma_chan *chan, dma_addr_t dest, int value, size_t len, unsigned long flags) { - if (!chan || !chan->device) + if (!chan || !chan->device || !chan->device->device_prep_dma_memset) return NULL; return chan->device->device_prep_dma_memset(chan, dest, value, @@ -824,6 +839,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg( struct scatterlist *src_sg, unsigned int src_nents, unsigned long flags) { + if (!chan || !chan->device || !chan->device->device_prep_dma_sg) + return NULL; + return chan->device->device_prep_dma_sg(chan, dst_sg, dst_nents, src_sg, src_nents, flags); } -- 2.7.4

7 years, 5 months

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[PATCH ghak82] audit: Fix wrong task in comparison of session ID

by Ondrej Mosnacek

The audit_filter_rules() function in auditsc.c compared the session ID with the credentials of the current task, while it should use the credentials of the task given to audit_filter_rules() as a parameter (tsk). GitHub issue: https://github.com/linux-audit/audit-kernel/issues/82 Fixes: 8fae47705685 ("audit: add support for session ID user filter") Cc: stable(a)vger.kernel.org Signed-off-by: Ondrej Mosnacek <omosnace(a)redhat.com> --- kernel/auditsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ec38e4d97c23..6d577a34b16b 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -513,7 +513,7 @@ static int audit_filter_rules(struct task_struct *tsk, result = audit_gid_comparator(cred->fsgid, f->op, f->gid); break; case AUDIT_SESSIONID: - sessionid = audit_get_sessionid(current); + sessionid = audit_get_sessionid(tsk); result = audit_comparator(sessionid, f->op, f->val); break; case AUDIT_PERS: -- 2.17.0

7 years, 5 months

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[merged] mm-dont-allow-deferred-pages-with-need_per_cpu_km.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm: don't allow deferred pages with NEED_PER_CPU_KM has been removed from the -mm tree. Its filename was mm-dont-allow-deferred-pages-with-need_per_cpu_km.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Pavel Tatashin <pasha.tatashin(a)oracle.com> Subject: mm: don't allow deferred pages with NEED_PER_CPU_KM It is unsafe to do virtual to physical translations before mm_init() is called if struct page is needed in order to determine the memory section number (see SECTION_IN_PAGE_FLAGS). This is because only in mm_init() we initialize struct pages for all the allocated memory when deferred struct pages are used. My recent fix c9e97a1997 ("mm: initialize pages on demand during boot") exposed this problem, because it greatly reduced number of pages that are initialized before mm_init(), but the problem existed even before my fix, as Fengguang Wu found. Below is a more detailed explanation of the problem. We initialize struct pages in four places: 1. Early in boot a small set of struct pages is initialized to fill the first section, and lower zones. 2. During mm_init() we initialize "struct pages" for all the memory that is allocated, i.e reserved in memblock. 3. Using on-demand logic when pages are allocated after mm_init call (when memblock is finished) 4. After smp_init() when the rest free deferred pages are initialized. The problem occurs if we try to do va to phys translation of a memory between steps 1 and 2. Because we have not yet initialized struct pages for all the reserved pages, it is inherently unsafe to do va to phys if the translation itself requires access of "struct page" as in case of this combination: CONFIG_SPARSE && !CONFIG_SPARSE_VMEMMAP The following path exposes the problem: start_kernel() trap_init() setup_cpu_entry_areas() setup_cpu_entry_area(cpu) get_cpu_gdt_paddr(cpu) per_cpu_ptr_to_phys(addr) pcpu_addr_to_page(addr) virt_to_page(addr) pfn_to_page(__pa(addr) >> PAGE_SHIFT) We disable this path by not allowing NEED_PER_CPU_KM with deferred struct pages feature. The problems are discussed in these threads: http://lkml.kernel.org/r/20180418135300.inazvpxjxowogyge@wfg-t540p.sh.intel… http://lkml.kernel.org/r/20180419013128.iurzouiqxvcnpbvz@wfg-t540p.sh.intel… http://lkml.kernel.org/r/20180426202619.2768-1-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180515175124.1770-1-pasha.tatashin@oracle.com Fixes: 3a80a7fa7989 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set") Signed-off-by: Pavel Tatashin <pasha.tatashin(a)oracle.com> Acked-by: Michal Hocko <mhocko(a)suse.com> Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Cc: Steven Sistare <steven.sistare(a)oracle.com> Cc: Daniel Jordan <daniel.m.jordan(a)oracle.com> Cc: Mel Gorman <mgorman(a)techsingularity.net> Cc: Fengguang Wu <fengguang.wu(a)intel.com> Cc: Dennis Zhou <dennisszhou(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/Kconfig | 1 + 1 file changed, 1 insertion(+) diff -puN mm/Kconfig~mm-dont-allow-deferred-pages-with-need_per_cpu_km mm/Kconfig --- a/mm/Kconfig~mm-dont-allow-deferred-pages-with-need_per_cpu_km +++ a/mm/Kconfig @@ -636,6 +636,7 @@ config DEFERRED_STRUCT_PAGE_INIT default n depends on NO_BOOTMEM depends on !FLATMEM + depends on !NEED_PER_CPU_KM help Ordinarily all struct pages are initialised during early boot in a single thread. On very large machines this can take a considerable _ Patches currently in -mm which might be from pasha.tatashin(a)oracle.com are sparc64-ng4-memset-32-bits-overflow.patch

7 years, 5 months

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[merged] radix-tree-fix-multi-order-iteration-race.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: radix tree: fix multi-order iteration race has been removed from the -mm tree. Its filename was radix-tree-fix-multi-order-iteration-race.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Ross Zwisler <ross.zwisler(a)linux.intel.com> Subject: radix tree: fix multi-order iteration race Fix a race in the multi-order iteration code which causes the kernel to hit a GP fault. This was first seen with a production v4.15 based kernel (4.15.6-300.fc27.x86_64) utilizing a DAX workload which used order 9 PMD DAX entries. The race has to do with how we tear down multi-order sibling entries when we are removing an item from the tree. Remember for example that an order 2 entry looks like this: struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling] where 'entry' is in some slot in the struct radix_tree_node, and the three slots following 'entry' contain sibling pointers which point back to 'entry.' When we delete 'entry' from the tree, we call : radix_tree_delete() radix_tree_delete_item() __radix_tree_delete() replace_slot() replace_slot() first removes the siblings in order from the first to the last, then at then replaces 'entry' with NULL. This means that for a brief period of time we end up with one or more of the siblings removed, so: struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling] This causes an issue if you have a reader iterating over the slots in the tree via radix_tree_for_each_slot() while only under rcu_read_lock()/rcu_read_unlock() protection. This is a common case in mm/filemap.c. The issue is that when __radix_tree_next_slot() => skip_siblings() tries to skip over the sibling entries in the slots, it currently does so with an exact match on the slot directly preceding our current slot. Normally this works: V preceding slot struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling] ^ current slot This lets you find the first sibling, and you skip them all in order. But in the case where one of the siblings is NULL, that slot is skipped and then our sibling detection is interrupted: V preceding slot struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling] ^ current slot This means that the sibling pointers aren't recognized since they point all the way back to 'entry', so we think that they are normal internal radix tree pointers. This causes us to think we need to walk down to a struct radix_tree_node starting at the address of 'entry'. In a real running kernel this will crash the thread with a GP fault when you try and dereference the slots in your broken node starting at 'entry'. We fix this race by fixing the way that skip_siblings() detects sibling nodes. Instead of testing against the preceding slot we instead look for siblings via is_sibling_entry() which compares against the position of the struct radix_tree_node.slots[] array. This ensures that sibling entries are properly identified, even if they are no longer contiguous with the 'entry' they point to. Link: http://lkml.kernel.org/r/20180503192430.7582-6-ross.zwisler@linux.intel.com Fixes: 148deab223b2 ("radix-tree: improve multiorder iterators") Signed-off-by: Ross Zwisler <ross.zwisler(a)linux.intel.com> Reported-by: CR, Sapthagirish <sapthagirish.cr(a)intel.com> Reviewed-by: Jan Kara <jack(a)suse.cz> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: Christoph Hellwig <hch(a)lst.de> Cc: Dan Williams <dan.j.williams(a)intel.com> Cc: Dave Chinner <david(a)fromorbit.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- lib/radix-tree.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff -puN lib/radix-tree.c~radix-tree-fix-multi-order-iteration-race lib/radix-tree.c --- a/lib/radix-tree.c~radix-tree-fix-multi-order-iteration-race +++ a/lib/radix-tree.c @@ -1612,11 +1612,9 @@ static void set_iter_tags(struct radix_t static void __rcu **skip_siblings(struct radix_tree_node **nodep, void __rcu **slot, struct radix_tree_iter *iter) { - void *sib = node_to_entry(slot - 1); - while (iter->index < iter->next_index) { *nodep = rcu_dereference_raw(*slot); - if (*nodep && *nodep != sib) + if (*nodep && !is_sibling_entry(iter->node, *nodep)) return slot; slot++; iter->index = __radix_tree_iter_add(iter, 1); @@ -1631,7 +1629,7 @@ void __rcu **__radix_tree_next_slot(void struct radix_tree_iter *iter, unsigned flags) { unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; - struct radix_tree_node *node = rcu_dereference_raw(*slot); + struct radix_tree_node *node; slot = skip_siblings(&node, slot, iter); _ Patches currently in -mm which might be from ross.zwisler(a)linux.intel.com are

7 years, 5 months

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[merged] lib-test_bitmapc-fix-bitmap-optimisation-tests-to-report-errors-correctly.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: lib/test_bitmap.c: fix bitmap optimisation tests to report errors correctly has been removed from the -mm tree. Its filename was lib-test_bitmapc-fix-bitmap-optimisation-tests-to-report-errors-correctly.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Matthew Wilcox <mawilcox(a)microsoft.com> Subject: lib/test_bitmap.c: fix bitmap optimisation tests to report errors correctly I had neglected to increment the error counter when the tests failed, which made the tests noisy when they fail, but not actually return an error code. Link: http://lkml.kernel.org/r/20180509114328.9887-1-mpe@ellerman.id.au Fixes: 3cc78125a081 ("lib/test_bitmap.c: add optimisation tests") Signed-off-by: Matthew Wilcox <mawilcox(a)microsoft.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Reported-by: Michael Ellerman <mpe(a)ellerman.id.au> Tested-by: Michael Ellerman <mpe(a)ellerman.id.au> Reviewed-by: Kees Cook <keescook(a)chromium.org> Cc: Yury Norov <ynorov(a)caviumnetworks.com> Cc: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com> Cc: Geert Uytterhoeven <geert(a)linux-m68k.org> Cc: <stable(a)vger.kernel.org> [4.13+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- lib/test_bitmap.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff -puN lib/test_bitmap.c~lib-test_bitmapc-fix-bitmap-optimisation-tests-to-report-errors-correctly lib/test_bitmap.c --- a/lib/test_bitmap.c~lib-test_bitmapc-fix-bitmap-optimisation-tests-to-report-errors-correctly +++ a/lib/test_bitmap.c @@ -331,23 +331,32 @@ static void noinline __init test_mem_opt unsigned int start, nbits; for (start = 0; start < 1024; start += 8) { - memset(bmap1, 0x5a, sizeof(bmap1)); - memset(bmap2, 0x5a, sizeof(bmap2)); for (nbits = 0; nbits < 1024 - start; nbits += 8) { + memset(bmap1, 0x5a, sizeof(bmap1)); + memset(bmap2, 0x5a, sizeof(bmap2)); + bitmap_set(bmap1, start, nbits); __bitmap_set(bmap2, start, nbits); - if (!bitmap_equal(bmap1, bmap2, 1024)) + if (!bitmap_equal(bmap1, bmap2, 1024)) { printk("set not equal %d %d\n", start, nbits); - if (!__bitmap_equal(bmap1, bmap2, 1024)) + failed_tests++; + } + if (!__bitmap_equal(bmap1, bmap2, 1024)) { printk("set not __equal %d %d\n", start, nbits); + failed_tests++; + } bitmap_clear(bmap1, start, nbits); __bitmap_clear(bmap2, start, nbits); - if (!bitmap_equal(bmap1, bmap2, 1024)) + if (!bitmap_equal(bmap1, bmap2, 1024)) { printk("clear not equal %d %d\n", start, nbits); - if (!__bitmap_equal(bmap1, bmap2, 1024)) + failed_tests++; + } + if (!__bitmap_equal(bmap1, bmap2, 1024)) { printk("clear not __equal %d %d\n", start, nbits); + failed_tests++; + } } } } _ Patches currently in -mm which might be from mawilcox(a)microsoft.com are idr-fix-invalid-ptr-dereference-on-item-delete.patch slab-__gfp_zero-is-incompatible-with-a-constructor.patch s390-use-_refcount-for-pgtables.patch mm-split-page_type-out-from-_mapcount.patch mm-mark-pages-in-use-for-page-tables.patch mm-switch-s_mem-and-slab_cache-in-struct-page.patch mm-move-private-union-within-struct-page.patch mm-move-_refcount-out-of-struct-page-union.patch mm-combine-first-three-unions-in-struct-page.patch mm-use-page-deferred_list.patch mm-move-lru-union-within-struct-page.patch mm-combine-lru-and-main-union-in-struct-page.patch mm-improve-struct-page-documentation.patch mm-add-pt_mm-to-struct-page.patch mm-add-hmm_data-to-struct-page.patch slabslub-remove-rcu_head-size-checks.patch slub-remove-kmem_cache-reserved.patch slub-remove-reserved-file-from-sysfs.patch mm-distinguish-vmalloc-pages.patch ida-remove-simple_ida_lock.patch

7 years, 5 months

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Please include following patches to 4.4/4.9/4.14

by Nikolay Borisov

Hello Greg, Here are trivial backports for upstream commit, which is tagged as stable: 02a3307aa9c2 ("btrfs: fix reading stale metadata blocks after degraded raid1 mounts") Regards, Nikolay

7 years, 5 months

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[PATCH resend] libata: blacklist Micron 500IT SSD with MU01 firmware

by Sudip Mukherjee

From: Sudip Mukherjee <sudipm.mukherjee(a)gmail.com> While whitelisting Micron M500DC drives, the tweaked blacklist entry enabled queued TRIM from M500IT variants also. But these do not support queued TRIM. And while using those SSDs with the latest kernel we have seen errors and even the partition table getting corrupted. Some part from the dmesg: [ 6.727384] ata1.00: ATA-9: Micron_M500IT_MTFDDAK060MBD, MU01, max UDMA/133 [ 6.727390] ata1.00: 117231408 sectors, multi 16: LBA48 NCQ (depth 31/32), AA [ 6.741026] ata1.00: supports DRM functions and may not be fully accessible [ 6.759887] ata1.00: configured for UDMA/133 [ 6.762256] scsi 0:0:0:0: Direct-Access ATA Micron_M500IT_MT MU01 PQ: 0 ANSI: 5 and then for the error: [ 120.860334] ata1.00: exception Emask 0x1 SAct 0x7ffc0007 SErr 0x0 action 0x6 frozen [ 120.860338] ata1.00: irq_stat 0x40000008 [ 120.860342] ata1.00: failed command: SEND FPDMA QUEUED [ 120.860351] ata1.00: cmd 64/01:00:00:00:00/00:00:00:00:00/a0 tag 0 ncq dma 512 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x5 (timeout) [ 120.860353] ata1.00: status: { DRDY } [ 120.860543] ata1: hard resetting link [ 121.166128] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 121.166376] ata1.00: supports DRM functions and may not be fully accessible [ 121.186238] ata1.00: supports DRM functions and may not be fully accessible [ 121.204445] ata1.00: configured for UDMA/133 [ 121.204454] ata1.00: device reported invalid CHS sector 0 [ 121.204541] sd 0:0:0:0: [sda] tag#18 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08 [ 121.204546] sd 0:0:0:0: [sda] tag#18 Sense Key : 0x5 [current] [ 121.204550] sd 0:0:0:0: [sda] tag#18 ASC=0x21 ASCQ=0x4 [ 121.204555] sd 0:0:0:0: [sda] tag#18 CDB: opcode=0x93 93 08 00 00 00 00 00 04 28 80 00 00 00 30 00 00 [ 121.204559] print_req_error: I/O error, dev sda, sector 272512 After few reboots with these errors, and the SSD is corrupted. After blacklisting it, the errors are not seen and the SSD does not get corrupted any more. Fixes: 243918be6393 ("libata: Do not blacklist Micron M500DC") Cc: Martin K. Petersen <martin.petersen(a)oracle.com> Cc: stable(a)vger.kernel.org Signed-off-by: Sudip Mukherjee <sudipm.mukherjee(a)gmail.com> --- This is a resend of v1. v2 was blacklisting all Micron SSDs but Martin has confirmed that only M500IT with MU01 firmware is affected. drivers/ata/libata-core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index eaf0f42f6f28..cdcd55cb2a9a 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4554,6 +4554,8 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = { { "SanDisk SD7UB3Q*G1001", NULL, ATA_HORKAGE_NOLPM, }, /* devices that don't properly handle queued TRIM commands */ + { "Micron_M500IT_*", "MU01", ATA_HORKAGE_NO_NCQ_TRIM | + ATA_HORKAGE_ZERO_AFTER_TRIM, }, { "Micron_M500_*", NULL, ATA_HORKAGE_NO_NCQ_TRIM | ATA_HORKAGE_ZERO_AFTER_TRIM, }, { "Crucial_CT*M500*", NULL, ATA_HORKAGE_NO_NCQ_TRIM | -- 2.11.0

7 years, 5 months

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FAILED: patch "[PATCH] btrfs: Fix delalloc inodes invalidation during transaction" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From fe816d0f1d4c31c4c31d42ca78a87660565fc800 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov <nborisov(a)suse.com> Date: Fri, 27 Apr 2018 12:21:53 +0300 Subject: [PATCH] btrfs: Fix delalloc inodes invalidation during transaction abort When a transaction is aborted btrfs_cleanup_transaction is called to cleanup all the various in-flight bits and pieces which migth be active. One of those is delalloc inodes - inodes which have dirty pages which haven't been persisted yet. Currently the process of freeing such delalloc inodes in exceptional circumstances such as transaction abort boiled down to calling btrfs_invalidate_inodes whose sole job is to invalidate the dentries for all inodes related to a root. This is in fact wrong and insufficient since such delalloc inodes will likely have pending pages or ordered-extents and will be linked to the sb->s_inode_list. This means that unmounting a btrfs instance with an aborted transaction could potentially lead inodes/their pages visible to the system long after their superblock has been freed. This in turn leads to a "use-after-free" situation once page shrink is triggered. This situation could be simulated by running generic/019 which would cause such inodes to be left hanging, followed by generic/176 which causes memory pressure and page eviction which lead to touching the freed super block instance. This situation is additionally detected by the unmount code of VFS with the following message: "VFS: Busy inodes after unmount of Self-destruct in 5 seconds. Have a nice day..." Additionally btrfs hits WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); in free_fs_root for the same reason. This patch aims to rectify the sitaution by doing the following: 1. Change btrfs_destroy_delalloc_inodes so that it calls invalidate_inode_pages2 for every inode on the delalloc list, this ensures that all the pages of the inode are released. This function boils down to calling btrfs_releasepage. During test I observed cases where inodes on the delalloc list were having an i_count of 0, so this necessitates using igrab to be sure we are working on a non-freed inode. 2. Since calling btrfs_releasepage might queue delayed iputs move the call out to btrfs_cleanup_transaction in btrfs_error_commit_super before calling run_delayed_iputs for the last time. This is necessary to ensure that delayed iputs are run. Note: this patch is tagged for 4.14 stable but the fix applies to older versions too but needs to be backported manually due to conflicts. CC: stable(a)vger.kernel.org # 4.14.x: 2b8773313494: btrfs: Split btrfs_del_delalloc_inode into 2 functions CC: stable(a)vger.kernel.org # 4.14.x Signed-off-by: Nikolay Borisov <nborisov(a)suse.com> Reviewed-by: David Sterba <dsterba(a)suse.com> [ add comment to igrab ] Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 60caa68c3618..c3504b4d281b 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3818,6 +3818,7 @@ void close_ctree(struct btrfs_fs_info *fs_info) set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags); btrfs_free_qgroup_config(fs_info); + ASSERT(list_empty(&fs_info->delalloc_roots)); if (percpu_counter_sum(&fs_info->delalloc_bytes)) { btrfs_info(fs_info, "at unmount delalloc count %lld", @@ -4125,15 +4126,15 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info) static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info) { + /* cleanup FS via transaction */ + btrfs_cleanup_transaction(fs_info); + mutex_lock(&fs_info->cleaner_mutex); btrfs_run_delayed_iputs(fs_info); mutex_unlock(&fs_info->cleaner_mutex); down_write(&fs_info->cleanup_work_sem); up_write(&fs_info->cleanup_work_sem); - - /* cleanup FS via transaction */ - btrfs_cleanup_transaction(fs_info); } static void btrfs_destroy_ordered_extents(struct btrfs_root *root) @@ -4258,19 +4259,23 @@ static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root) list_splice_init(&root->delalloc_inodes, &splice); while (!list_empty(&splice)) { + struct inode *inode = NULL; btrfs_inode = list_first_entry(&splice, struct btrfs_inode, delalloc_inodes); - - list_del_init(&btrfs_inode->delalloc_inodes); - clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, - &btrfs_inode->runtime_flags); + __btrfs_del_delalloc_inode(root, btrfs_inode); spin_unlock(&root->delalloc_lock); - btrfs_invalidate_inodes(btrfs_inode->root); - + /* + * Make sure we get a live inode and that it'll not disappear + * meanwhile. + */ + inode = igrab(&btrfs_inode->vfs_inode); + if (inode) { + invalidate_inode_pages2(inode->i_mapping); + iput(inode); + } spin_lock(&root->delalloc_lock); } - spin_unlock(&root->delalloc_lock); } @@ -4286,7 +4291,6 @@ static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info) while (!list_empty(&splice)) { root = list_first_entry(&splice, struct btrfs_root, delalloc_root); - list_del_init(&root->delalloc_root); root = btrfs_grab_fs_root(root); BUG_ON(!root); spin_unlock(&fs_info->delalloc_root_lock);

7 years, 5 months

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FAILED: patch "[PATCH] btrfs: Fix delalloc inodes invalidation during transaction" failed to apply to 4.16-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From fe816d0f1d4c31c4c31d42ca78a87660565fc800 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov <nborisov(a)suse.com> Date: Fri, 27 Apr 2018 12:21:53 +0300 Subject: [PATCH] btrfs: Fix delalloc inodes invalidation during transaction abort When a transaction is aborted btrfs_cleanup_transaction is called to cleanup all the various in-flight bits and pieces which migth be active. One of those is delalloc inodes - inodes which have dirty pages which haven't been persisted yet. Currently the process of freeing such delalloc inodes in exceptional circumstances such as transaction abort boiled down to calling btrfs_invalidate_inodes whose sole job is to invalidate the dentries for all inodes related to a root. This is in fact wrong and insufficient since such delalloc inodes will likely have pending pages or ordered-extents and will be linked to the sb->s_inode_list. This means that unmounting a btrfs instance with an aborted transaction could potentially lead inodes/their pages visible to the system long after their superblock has been freed. This in turn leads to a "use-after-free" situation once page shrink is triggered. This situation could be simulated by running generic/019 which would cause such inodes to be left hanging, followed by generic/176 which causes memory pressure and page eviction which lead to touching the freed super block instance. This situation is additionally detected by the unmount code of VFS with the following message: "VFS: Busy inodes after unmount of Self-destruct in 5 seconds. Have a nice day..." Additionally btrfs hits WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); in free_fs_root for the same reason. This patch aims to rectify the sitaution by doing the following: 1. Change btrfs_destroy_delalloc_inodes so that it calls invalidate_inode_pages2 for every inode on the delalloc list, this ensures that all the pages of the inode are released. This function boils down to calling btrfs_releasepage. During test I observed cases where inodes on the delalloc list were having an i_count of 0, so this necessitates using igrab to be sure we are working on a non-freed inode. 2. Since calling btrfs_releasepage might queue delayed iputs move the call out to btrfs_cleanup_transaction in btrfs_error_commit_super before calling run_delayed_iputs for the last time. This is necessary to ensure that delayed iputs are run. Note: this patch is tagged for 4.14 stable but the fix applies to older versions too but needs to be backported manually due to conflicts. CC: stable(a)vger.kernel.org # 4.14.x: 2b8773313494: btrfs: Split btrfs_del_delalloc_inode into 2 functions CC: stable(a)vger.kernel.org # 4.14.x Signed-off-by: Nikolay Borisov <nborisov(a)suse.com> Reviewed-by: David Sterba <dsterba(a)suse.com> [ add comment to igrab ] Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 60caa68c3618..c3504b4d281b 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3818,6 +3818,7 @@ void close_ctree(struct btrfs_fs_info *fs_info) set_bit(BTRFS_FS_CLOSING_DONE, &fs_info->flags); btrfs_free_qgroup_config(fs_info); + ASSERT(list_empty(&fs_info->delalloc_roots)); if (percpu_counter_sum(&fs_info->delalloc_bytes)) { btrfs_info(fs_info, "at unmount delalloc count %lld", @@ -4125,15 +4126,15 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info) static void btrfs_error_commit_super(struct btrfs_fs_info *fs_info) { + /* cleanup FS via transaction */ + btrfs_cleanup_transaction(fs_info); + mutex_lock(&fs_info->cleaner_mutex); btrfs_run_delayed_iputs(fs_info); mutex_unlock(&fs_info->cleaner_mutex); down_write(&fs_info->cleanup_work_sem); up_write(&fs_info->cleanup_work_sem); - - /* cleanup FS via transaction */ - btrfs_cleanup_transaction(fs_info); } static void btrfs_destroy_ordered_extents(struct btrfs_root *root) @@ -4258,19 +4259,23 @@ static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root) list_splice_init(&root->delalloc_inodes, &splice); while (!list_empty(&splice)) { + struct inode *inode = NULL; btrfs_inode = list_first_entry(&splice, struct btrfs_inode, delalloc_inodes); - - list_del_init(&btrfs_inode->delalloc_inodes); - clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, - &btrfs_inode->runtime_flags); + __btrfs_del_delalloc_inode(root, btrfs_inode); spin_unlock(&root->delalloc_lock); - btrfs_invalidate_inodes(btrfs_inode->root); - + /* + * Make sure we get a live inode and that it'll not disappear + * meanwhile. + */ + inode = igrab(&btrfs_inode->vfs_inode); + if (inode) { + invalidate_inode_pages2(inode->i_mapping); + iput(inode); + } spin_lock(&root->delalloc_lock); } - spin_unlock(&root->delalloc_lock); } @@ -4286,7 +4291,6 @@ static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info) while (!list_empty(&splice)) { root = list_first_entry(&splice, struct btrfs_root, delalloc_root); - list_del_init(&root->delalloc_root); root = btrfs_grab_fs_root(root); BUG_ON(!root); spin_unlock(&fs_info->delalloc_root_lock);

7 years, 5 months

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FAILED: patch "[PATCH] Btrfs: send, fix invalid access to commit roots due to" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6f2f0b394b54e2b159ef969a0b5274e9bbf82ff2 Mon Sep 17 00:00:00 2001 From: Robbie Ko <robbieko(a)synology.com> Date: Mon, 14 May 2018 10:51:34 +0800 Subject: [PATCH] Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting [BUG] btrfs incremental send BUG happens when creating a snapshot of snapshot that is being used by send. [REASON] The problem can happen if while we are doing a send one of the snapshots used (parent or send) is snapshotted, because snapshoting implies COWing the root of the source subvolume/snapshot. 1. When doing an incremental send, the send process will get the commit roots from the parent and send snapshots, and add references to them through extent_buffer_get(). 2. When a snapshot/subvolume is snapshotted, its root node is COWed (transaction.c:create_pending_snapshot()). 3. COWing releases the space used by the node immediately, through: __btrfs_cow_block() --btrfs_free_tree_block() ----btrfs_add_free_space(bytenr of node) 4. Because send doesn't hold a transaction open, it's possible that the transaction used to create the snapshot commits, switches the commit root and the old space used by the previous root node gets assigned to some other node allocation. Allocation of a new node will use the existing extent buffer found in memory, which we previously got a reference through extent_buffer_get(), and allow the extent buffer's content (pages) to be modified: btrfs_alloc_tree_block --btrfs_reserve_extent ----find_free_extent (get bytenr of old node) --btrfs_init_new_buffer (use bytenr of old node) ----btrfs_find_create_tree_block ------alloc_extent_buffer --------find_extent_buffer (get old node) 5. So send can access invalid memory content and have unpredictable behaviour. [FIX] So we fix the problem by copying the commit roots of the send and parent snapshots and use those copies. CallTrace looks like this: ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:1861! invalid opcode: 0000 [#1] SMP CPU: 6 PID: 24235 Comm: btrfs Tainted: P O 3.10.105 #23721 ffff88046652d680 ti: ffff88041b720000 task.ti: ffff88041b720000 RIP: 0010:[<ffffffffa08dd0e8>] read_node_slot+0x108/0x110 [btrfs] RSP: 0018:ffff88041b723b68 EFLAGS: 00010246 RAX: ffff88043ca6b000 RBX: ffff88041b723c50 RCX: ffff880000000000 RDX: 000000000000004c RSI: ffff880314b133f8 RDI: ffff880458b24000 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88041b723c66 R10: 0000000000000001 R11: 0000000000001000 R12: ffff8803f3e48890 R13: ffff8803f3e48880 R14: ffff880466351800 R15: 0000000000000001 FS: 00007f8c321dc8c0(0000) GS:ffff88047fcc0000(0000) CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 R2: 00007efd1006d000 CR3: 0000000213a24000 CR4: 00000000003407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff88041b723c50 ffff8803f3e48880 ffff8803f3e48890 ffff8803f3e48880 ffff880466351800 0000000000000001 ffffffffa08dd9d7 ffff88041b723c50 ffff8803f3e48880 ffff88041b723c66 ffffffffa08dde85 a9ff88042d2c4400 Call Trace: [<ffffffffa08dd9d7>] ? tree_move_down.isra.33+0x27/0x50 [btrfs] [<ffffffffa08dde85>] ? tree_advance+0xb5/0xc0 [btrfs] [<ffffffffa08e83d4>] ? btrfs_compare_trees+0x2d4/0x760 [btrfs] [<ffffffffa0982050>] ? finish_inode_if_needed+0x870/0x870 [btrfs] [<ffffffffa09841ea>] ? btrfs_ioctl_send+0xeda/0x1050 [btrfs] [<ffffffffa094bd3d>] ? btrfs_ioctl+0x1e3d/0x33f0 [btrfs] [<ffffffff81111133>] ? handle_pte_fault+0x373/0x990 [<ffffffff8153a096>] ? atomic_notifier_call_chain+0x16/0x20 [<ffffffff81063256>] ? set_task_cpu+0xb6/0x1d0 [<ffffffff811122c3>] ? handle_mm_fault+0x143/0x2a0 [<ffffffff81539cc0>] ? __do_page_fault+0x1d0/0x500 [<ffffffff81062f07>] ? check_preempt_curr+0x57/0x90 [<ffffffff8115075a>] ? do_vfs_ioctl+0x4aa/0x990 [<ffffffff81034f83>] ? do_fork+0x113/0x3b0 [<ffffffff812dd7d7>] ? trace_hardirqs_off_thunk+0x3a/0x6c [<ffffffff81150cc8>] ? SyS_ioctl+0x88/0xa0 [<ffffffff8153e422>] ? system_call_fastpath+0x16/0x1b ---[ end trace 29576629ee80b2e1 ]--- Fixes: 7069830a9e38 ("Btrfs: add btrfs_compare_trees function") CC: stable(a)vger.kernel.org # 3.6+ Signed-off-by: Robbie Ko <robbieko(a)synology.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 3fd44835b386..63488f0b850f 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -5414,12 +5414,24 @@ int btrfs_compare_trees(struct btrfs_root *left_root, down_read(&fs_info->commit_root_sem); left_level = btrfs_header_level(left_root->commit_root); left_root_level = left_level; - left_path->nodes[left_level] = left_root->commit_root; + left_path->nodes[left_level] = + btrfs_clone_extent_buffer(left_root->commit_root); + if (!left_path->nodes[left_level]) { + up_read(&fs_info->commit_root_sem); + ret = -ENOMEM; + goto out; + } extent_buffer_get(left_path->nodes[left_level]); right_level = btrfs_header_level(right_root->commit_root); right_root_level = right_level; - right_path->nodes[right_level] = right_root->commit_root; + right_path->nodes[right_level] = + btrfs_clone_extent_buffer(right_root->commit_root); + if (!right_path->nodes[right_level]) { + up_read(&fs_info->commit_root_sem); + ret = -ENOMEM; + goto out; + } extent_buffer_get(right_path->nodes[right_level]); up_read(&fs_info->commit_root_sem);

7 years, 5 months

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FAILED: patch "[PATCH] Btrfs: send, fix invalid access to commit roots due to" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6f2f0b394b54e2b159ef969a0b5274e9bbf82ff2 Mon Sep 17 00:00:00 2001 From: Robbie Ko <robbieko(a)synology.com> Date: Mon, 14 May 2018 10:51:34 +0800 Subject: [PATCH] Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting [BUG] btrfs incremental send BUG happens when creating a snapshot of snapshot that is being used by send. [REASON] The problem can happen if while we are doing a send one of the snapshots used (parent or send) is snapshotted, because snapshoting implies COWing the root of the source subvolume/snapshot. 1. When doing an incremental send, the send process will get the commit roots from the parent and send snapshots, and add references to them through extent_buffer_get(). 2. When a snapshot/subvolume is snapshotted, its root node is COWed (transaction.c:create_pending_snapshot()). 3. COWing releases the space used by the node immediately, through: __btrfs_cow_block() --btrfs_free_tree_block() ----btrfs_add_free_space(bytenr of node) 4. Because send doesn't hold a transaction open, it's possible that the transaction used to create the snapshot commits, switches the commit root and the old space used by the previous root node gets assigned to some other node allocation. Allocation of a new node will use the existing extent buffer found in memory, which we previously got a reference through extent_buffer_get(), and allow the extent buffer's content (pages) to be modified: btrfs_alloc_tree_block --btrfs_reserve_extent ----find_free_extent (get bytenr of old node) --btrfs_init_new_buffer (use bytenr of old node) ----btrfs_find_create_tree_block ------alloc_extent_buffer --------find_extent_buffer (get old node) 5. So send can access invalid memory content and have unpredictable behaviour. [FIX] So we fix the problem by copying the commit roots of the send and parent snapshots and use those copies. CallTrace looks like this: ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:1861! invalid opcode: 0000 [#1] SMP CPU: 6 PID: 24235 Comm: btrfs Tainted: P O 3.10.105 #23721 ffff88046652d680 ti: ffff88041b720000 task.ti: ffff88041b720000 RIP: 0010:[<ffffffffa08dd0e8>] read_node_slot+0x108/0x110 [btrfs] RSP: 0018:ffff88041b723b68 EFLAGS: 00010246 RAX: ffff88043ca6b000 RBX: ffff88041b723c50 RCX: ffff880000000000 RDX: 000000000000004c RSI: ffff880314b133f8 RDI: ffff880458b24000 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88041b723c66 R10: 0000000000000001 R11: 0000000000001000 R12: ffff8803f3e48890 R13: ffff8803f3e48880 R14: ffff880466351800 R15: 0000000000000001 FS: 00007f8c321dc8c0(0000) GS:ffff88047fcc0000(0000) CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 R2: 00007efd1006d000 CR3: 0000000213a24000 CR4: 00000000003407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff88041b723c50 ffff8803f3e48880 ffff8803f3e48890 ffff8803f3e48880 ffff880466351800 0000000000000001 ffffffffa08dd9d7 ffff88041b723c50 ffff8803f3e48880 ffff88041b723c66 ffffffffa08dde85 a9ff88042d2c4400 Call Trace: [<ffffffffa08dd9d7>] ? tree_move_down.isra.33+0x27/0x50 [btrfs] [<ffffffffa08dde85>] ? tree_advance+0xb5/0xc0 [btrfs] [<ffffffffa08e83d4>] ? btrfs_compare_trees+0x2d4/0x760 [btrfs] [<ffffffffa0982050>] ? finish_inode_if_needed+0x870/0x870 [btrfs] [<ffffffffa09841ea>] ? btrfs_ioctl_send+0xeda/0x1050 [btrfs] [<ffffffffa094bd3d>] ? btrfs_ioctl+0x1e3d/0x33f0 [btrfs] [<ffffffff81111133>] ? handle_pte_fault+0x373/0x990 [<ffffffff8153a096>] ? atomic_notifier_call_chain+0x16/0x20 [<ffffffff81063256>] ? set_task_cpu+0xb6/0x1d0 [<ffffffff811122c3>] ? handle_mm_fault+0x143/0x2a0 [<ffffffff81539cc0>] ? __do_page_fault+0x1d0/0x500 [<ffffffff81062f07>] ? check_preempt_curr+0x57/0x90 [<ffffffff8115075a>] ? do_vfs_ioctl+0x4aa/0x990 [<ffffffff81034f83>] ? do_fork+0x113/0x3b0 [<ffffffff812dd7d7>] ? trace_hardirqs_off_thunk+0x3a/0x6c [<ffffffff81150cc8>] ? SyS_ioctl+0x88/0xa0 [<ffffffff8153e422>] ? system_call_fastpath+0x16/0x1b ---[ end trace 29576629ee80b2e1 ]--- Fixes: 7069830a9e38 ("Btrfs: add btrfs_compare_trees function") CC: stable(a)vger.kernel.org # 3.6+ Signed-off-by: Robbie Ko <robbieko(a)synology.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 3fd44835b386..63488f0b850f 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -5414,12 +5414,24 @@ int btrfs_compare_trees(struct btrfs_root *left_root, down_read(&fs_info->commit_root_sem); left_level = btrfs_header_level(left_root->commit_root); left_root_level = left_level; - left_path->nodes[left_level] = left_root->commit_root; + left_path->nodes[left_level] = + btrfs_clone_extent_buffer(left_root->commit_root); + if (!left_path->nodes[left_level]) { + up_read(&fs_info->commit_root_sem); + ret = -ENOMEM; + goto out; + } extent_buffer_get(left_path->nodes[left_level]); right_level = btrfs_header_level(right_root->commit_root); right_root_level = right_level; - right_path->nodes[right_level] = right_root->commit_root; + right_path->nodes[right_level] = + btrfs_clone_extent_buffer(right_root->commit_root); + if (!right_path->nodes[right_level]) { + up_read(&fs_info->commit_root_sem); + ret = -ENOMEM; + goto out; + } extent_buffer_get(right_path->nodes[right_level]); up_read(&fs_info->commit_root_sem);

7 years, 5 months

1
0
0 0

FAILED: patch "[PATCH] Btrfs: send, fix invalid access to commit roots due to" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6f2f0b394b54e2b159ef969a0b5274e9bbf82ff2 Mon Sep 17 00:00:00 2001 From: Robbie Ko <robbieko(a)synology.com> Date: Mon, 14 May 2018 10:51:34 +0800 Subject: [PATCH] Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting [BUG] btrfs incremental send BUG happens when creating a snapshot of snapshot that is being used by send. [REASON] The problem can happen if while we are doing a send one of the snapshots used (parent or send) is snapshotted, because snapshoting implies COWing the root of the source subvolume/snapshot. 1. When doing an incremental send, the send process will get the commit roots from the parent and send snapshots, and add references to them through extent_buffer_get(). 2. When a snapshot/subvolume is snapshotted, its root node is COWed (transaction.c:create_pending_snapshot()). 3. COWing releases the space used by the node immediately, through: __btrfs_cow_block() --btrfs_free_tree_block() ----btrfs_add_free_space(bytenr of node) 4. Because send doesn't hold a transaction open, it's possible that the transaction used to create the snapshot commits, switches the commit root and the old space used by the previous root node gets assigned to some other node allocation. Allocation of a new node will use the existing extent buffer found in memory, which we previously got a reference through extent_buffer_get(), and allow the extent buffer's content (pages) to be modified: btrfs_alloc_tree_block --btrfs_reserve_extent ----find_free_extent (get bytenr of old node) --btrfs_init_new_buffer (use bytenr of old node) ----btrfs_find_create_tree_block ------alloc_extent_buffer --------find_extent_buffer (get old node) 5. So send can access invalid memory content and have unpredictable behaviour. [FIX] So we fix the problem by copying the commit roots of the send and parent snapshots and use those copies. CallTrace looks like this: ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:1861! invalid opcode: 0000 [#1] SMP CPU: 6 PID: 24235 Comm: btrfs Tainted: P O 3.10.105 #23721 ffff88046652d680 ti: ffff88041b720000 task.ti: ffff88041b720000 RIP: 0010:[<ffffffffa08dd0e8>] read_node_slot+0x108/0x110 [btrfs] RSP: 0018:ffff88041b723b68 EFLAGS: 00010246 RAX: ffff88043ca6b000 RBX: ffff88041b723c50 RCX: ffff880000000000 RDX: 000000000000004c RSI: ffff880314b133f8 RDI: ffff880458b24000 RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88041b723c66 R10: 0000000000000001 R11: 0000000000001000 R12: ffff8803f3e48890 R13: ffff8803f3e48880 R14: ffff880466351800 R15: 0000000000000001 FS: 00007f8c321dc8c0(0000) GS:ffff88047fcc0000(0000) CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 R2: 00007efd1006d000 CR3: 0000000213a24000 CR4: 00000000003407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff88041b723c50 ffff8803f3e48880 ffff8803f3e48890 ffff8803f3e48880 ffff880466351800 0000000000000001 ffffffffa08dd9d7 ffff88041b723c50 ffff8803f3e48880 ffff88041b723c66 ffffffffa08dde85 a9ff88042d2c4400 Call Trace: [<ffffffffa08dd9d7>] ? tree_move_down.isra.33+0x27/0x50 [btrfs] [<ffffffffa08dde85>] ? tree_advance+0xb5/0xc0 [btrfs] [<ffffffffa08e83d4>] ? btrfs_compare_trees+0x2d4/0x760 [btrfs] [<ffffffffa0982050>] ? finish_inode_if_needed+0x870/0x870 [btrfs] [<ffffffffa09841ea>] ? btrfs_ioctl_send+0xeda/0x1050 [btrfs] [<ffffffffa094bd3d>] ? btrfs_ioctl+0x1e3d/0x33f0 [btrfs] [<ffffffff81111133>] ? handle_pte_fault+0x373/0x990 [<ffffffff8153a096>] ? atomic_notifier_call_chain+0x16/0x20 [<ffffffff81063256>] ? set_task_cpu+0xb6/0x1d0 [<ffffffff811122c3>] ? handle_mm_fault+0x143/0x2a0 [<ffffffff81539cc0>] ? __do_page_fault+0x1d0/0x500 [<ffffffff81062f07>] ? check_preempt_curr+0x57/0x90 [<ffffffff8115075a>] ? do_vfs_ioctl+0x4aa/0x990 [<ffffffff81034f83>] ? do_fork+0x113/0x3b0 [<ffffffff812dd7d7>] ? trace_hardirqs_off_thunk+0x3a/0x6c [<ffffffff81150cc8>] ? SyS_ioctl+0x88/0xa0 [<ffffffff8153e422>] ? system_call_fastpath+0x16/0x1b ---[ end trace 29576629ee80b2e1 ]--- Fixes: 7069830a9e38 ("Btrfs: add btrfs_compare_trees function") CC: stable(a)vger.kernel.org # 3.6+ Signed-off-by: Robbie Ko <robbieko(a)synology.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 3fd44835b386..63488f0b850f 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -5414,12 +5414,24 @@ int btrfs_compare_trees(struct btrfs_root *left_root, down_read(&fs_info->commit_root_sem); left_level = btrfs_header_level(left_root->commit_root); left_root_level = left_level; - left_path->nodes[left_level] = left_root->commit_root; + left_path->nodes[left_level] = + btrfs_clone_extent_buffer(left_root->commit_root); + if (!left_path->nodes[left_level]) { + up_read(&fs_info->commit_root_sem); + ret = -ENOMEM; + goto out; + } extent_buffer_get(left_path->nodes[left_level]); right_level = btrfs_header_level(right_root->commit_root); right_root_level = right_level; - right_path->nodes[right_level] = right_root->commit_root; + right_path->nodes[right_level] = + btrfs_clone_extent_buffer(right_root->commit_root); + if (!right_path->nodes[right_level]) { + up_read(&fs_info->commit_root_sem); + ret = -ENOMEM; + goto out; + } extent_buffer_get(right_path->nodes[right_level]); up_read(&fs_info->commit_root_sem);

7 years, 5 months

1
0
0 0

FAILED: patch "[PATCH] btrfs: fix reading stale metadata blocks after degraded raid1" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 02a3307aa9c20b4f6626255b028f07f6cfa16feb Mon Sep 17 00:00:00 2001 From: Liu Bo <bo.liu(a)linux.alibaba.com> Date: Wed, 16 May 2018 01:37:36 +0800 Subject: [PATCH] btrfs: fix reading stale metadata blocks after degraded raid1 mounts If a btree block, aka. extent buffer, is not available in the extent buffer cache, it'll be read out from the disk instead, i.e. btrfs_search_slot() read_block_for_search() # hold parent and its lock, go to read child btrfs_release_path() read_tree_block() # read child Unfortunately, the parent lock got released before reading child, so commit 5bdd3536cbbe ("Btrfs: Fix block generation verification race") had used 0 as parent transid to read the child block. It forces read_tree_block() not to check if parent transid is different with the generation id of the child that it reads out from disk. A simple PoC is included in btrfs/124, 0. A two-disk raid1 btrfs, 1. Right after mkfs.btrfs, block A is allocated to be device tree's root. 2. Mount this filesystem and put it in use, after a while, device tree's root got COW but block A hasn't been allocated/overwritten yet. 3. Umount it and reload the btrfs module to remove both disks from the global @fs_devices list. 4. mount -odegraded dev1 and write some data, so now block A is allocated to be a leaf in checksum tree. Note that only dev1 has the latest metadata of this filesystem. 5. Umount it and mount it again normally (with both disks), since raid1 can pick up one disk by the writer task's pid, if btrfs_search_slot() needs to read block A, dev2 which does NOT have the latest metadata might be read for block A, then we got a stale block A. 6. As parent transid is not checked, block A is marked as uptodate and put into the extent buffer cache, so the future search won't bother to read disk again, which means it'll make changes on this stale one and make it dirty and flush it onto disk. To avoid the problem, parent transid needs to be passed to read_tree_block(). In order to get a valid parent transid, we need to hold the parent's lock until finishing reading child. This patch needs to be slightly adapted for stable kernels, the &first_key parameter added to read_tree_block() is from 4.16+ (581c1760415c4). The fix is to replace 0 by 'gen'. Fixes: 5bdd3536cbbe ("Btrfs: Fix block generation verification race") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Liu Bo <bo.liu(a)linux.alibaba.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 63488f0b850f..8c68961925b1 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2436,10 +2436,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, if (p->reada != READA_NONE) reada_for_search(fs_info, p, level, slot, key->objectid); - btrfs_release_path(p); - ret = -EAGAIN; - tmp = read_tree_block(fs_info, blocknr, 0, parent_level - 1, + tmp = read_tree_block(fs_info, blocknr, gen, parent_level - 1, &first_key); if (!IS_ERR(tmp)) { /* @@ -2454,6 +2452,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, } else { ret = PTR_ERR(tmp); } + + btrfs_release_path(p); return ret; }

7 years, 5 months

1
0
0 0

FAILED: patch "[PATCH] btrfs: fix reading stale metadata blocks after degraded raid1" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 02a3307aa9c20b4f6626255b028f07f6cfa16feb Mon Sep 17 00:00:00 2001 From: Liu Bo <bo.liu(a)linux.alibaba.com> Date: Wed, 16 May 2018 01:37:36 +0800 Subject: [PATCH] btrfs: fix reading stale metadata blocks after degraded raid1 mounts If a btree block, aka. extent buffer, is not available in the extent buffer cache, it'll be read out from the disk instead, i.e. btrfs_search_slot() read_block_for_search() # hold parent and its lock, go to read child btrfs_release_path() read_tree_block() # read child Unfortunately, the parent lock got released before reading child, so commit 5bdd3536cbbe ("Btrfs: Fix block generation verification race") had used 0 as parent transid to read the child block. It forces read_tree_block() not to check if parent transid is different with the generation id of the child that it reads out from disk. A simple PoC is included in btrfs/124, 0. A two-disk raid1 btrfs, 1. Right after mkfs.btrfs, block A is allocated to be device tree's root. 2. Mount this filesystem and put it in use, after a while, device tree's root got COW but block A hasn't been allocated/overwritten yet. 3. Umount it and reload the btrfs module to remove both disks from the global @fs_devices list. 4. mount -odegraded dev1 and write some data, so now block A is allocated to be a leaf in checksum tree. Note that only dev1 has the latest metadata of this filesystem. 5. Umount it and mount it again normally (with both disks), since raid1 can pick up one disk by the writer task's pid, if btrfs_search_slot() needs to read block A, dev2 which does NOT have the latest metadata might be read for block A, then we got a stale block A. 6. As parent transid is not checked, block A is marked as uptodate and put into the extent buffer cache, so the future search won't bother to read disk again, which means it'll make changes on this stale one and make it dirty and flush it onto disk. To avoid the problem, parent transid needs to be passed to read_tree_block(). In order to get a valid parent transid, we need to hold the parent's lock until finishing reading child. This patch needs to be slightly adapted for stable kernels, the &first_key parameter added to read_tree_block() is from 4.16+ (581c1760415c4). The fix is to replace 0 by 'gen'. Fixes: 5bdd3536cbbe ("Btrfs: Fix block generation verification race") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Liu Bo <bo.liu(a)linux.alibaba.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 63488f0b850f..8c68961925b1 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2436,10 +2436,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, if (p->reada != READA_NONE) reada_for_search(fs_info, p, level, slot, key->objectid); - btrfs_release_path(p); - ret = -EAGAIN; - tmp = read_tree_block(fs_info, blocknr, 0, parent_level - 1, + tmp = read_tree_block(fs_info, blocknr, gen, parent_level - 1, &first_key); if (!IS_ERR(tmp)) { /* @@ -2454,6 +2452,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, } else { ret = PTR_ERR(tmp); } + + btrfs_release_path(p); return ret; }

7 years, 5 months

1
0
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FAILED: patch "[PATCH] btrfs: fix reading stale metadata blocks after degraded raid1" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 02a3307aa9c20b4f6626255b028f07f6cfa16feb Mon Sep 17 00:00:00 2001 From: Liu Bo <bo.liu(a)linux.alibaba.com> Date: Wed, 16 May 2018 01:37:36 +0800 Subject: [PATCH] btrfs: fix reading stale metadata blocks after degraded raid1 mounts If a btree block, aka. extent buffer, is not available in the extent buffer cache, it'll be read out from the disk instead, i.e. btrfs_search_slot() read_block_for_search() # hold parent and its lock, go to read child btrfs_release_path() read_tree_block() # read child Unfortunately, the parent lock got released before reading child, so commit 5bdd3536cbbe ("Btrfs: Fix block generation verification race") had used 0 as parent transid to read the child block. It forces read_tree_block() not to check if parent transid is different with the generation id of the child that it reads out from disk. A simple PoC is included in btrfs/124, 0. A two-disk raid1 btrfs, 1. Right after mkfs.btrfs, block A is allocated to be device tree's root. 2. Mount this filesystem and put it in use, after a while, device tree's root got COW but block A hasn't been allocated/overwritten yet. 3. Umount it and reload the btrfs module to remove both disks from the global @fs_devices list. 4. mount -odegraded dev1 and write some data, so now block A is allocated to be a leaf in checksum tree. Note that only dev1 has the latest metadata of this filesystem. 5. Umount it and mount it again normally (with both disks), since raid1 can pick up one disk by the writer task's pid, if btrfs_search_slot() needs to read block A, dev2 which does NOT have the latest metadata might be read for block A, then we got a stale block A. 6. As parent transid is not checked, block A is marked as uptodate and put into the extent buffer cache, so the future search won't bother to read disk again, which means it'll make changes on this stale one and make it dirty and flush it onto disk. To avoid the problem, parent transid needs to be passed to read_tree_block(). In order to get a valid parent transid, we need to hold the parent's lock until finishing reading child. This patch needs to be slightly adapted for stable kernels, the &first_key parameter added to read_tree_block() is from 4.16+ (581c1760415c4). The fix is to replace 0 by 'gen'. Fixes: 5bdd3536cbbe ("Btrfs: Fix block generation verification race") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Liu Bo <bo.liu(a)linux.alibaba.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 63488f0b850f..8c68961925b1 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2436,10 +2436,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, if (p->reada != READA_NONE) reada_for_search(fs_info, p, level, slot, key->objectid); - btrfs_release_path(p); - ret = -EAGAIN; - tmp = read_tree_block(fs_info, blocknr, 0, parent_level - 1, + tmp = read_tree_block(fs_info, blocknr, gen, parent_level - 1, &first_key); if (!IS_ERR(tmp)) { /* @@ -2454,6 +2452,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, } else { ret = PTR_ERR(tmp); } + + btrfs_release_path(p); return ret; }

7 years, 5 months

1
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FAILED: patch "[PATCH] btrfs: fix reading stale metadata blocks after degraded raid1" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 02a3307aa9c20b4f6626255b028f07f6cfa16feb Mon Sep 17 00:00:00 2001 From: Liu Bo <bo.liu(a)linux.alibaba.com> Date: Wed, 16 May 2018 01:37:36 +0800 Subject: [PATCH] btrfs: fix reading stale metadata blocks after degraded raid1 mounts If a btree block, aka. extent buffer, is not available in the extent buffer cache, it'll be read out from the disk instead, i.e. btrfs_search_slot() read_block_for_search() # hold parent and its lock, go to read child btrfs_release_path() read_tree_block() # read child Unfortunately, the parent lock got released before reading child, so commit 5bdd3536cbbe ("Btrfs: Fix block generation verification race") had used 0 as parent transid to read the child block. It forces read_tree_block() not to check if parent transid is different with the generation id of the child that it reads out from disk. A simple PoC is included in btrfs/124, 0. A two-disk raid1 btrfs, 1. Right after mkfs.btrfs, block A is allocated to be device tree's root. 2. Mount this filesystem and put it in use, after a while, device tree's root got COW but block A hasn't been allocated/overwritten yet. 3. Umount it and reload the btrfs module to remove both disks from the global @fs_devices list. 4. mount -odegraded dev1 and write some data, so now block A is allocated to be a leaf in checksum tree. Note that only dev1 has the latest metadata of this filesystem. 5. Umount it and mount it again normally (with both disks), since raid1 can pick up one disk by the writer task's pid, if btrfs_search_slot() needs to read block A, dev2 which does NOT have the latest metadata might be read for block A, then we got a stale block A. 6. As parent transid is not checked, block A is marked as uptodate and put into the extent buffer cache, so the future search won't bother to read disk again, which means it'll make changes on this stale one and make it dirty and flush it onto disk. To avoid the problem, parent transid needs to be passed to read_tree_block(). In order to get a valid parent transid, we need to hold the parent's lock until finishing reading child. This patch needs to be slightly adapted for stable kernels, the &first_key parameter added to read_tree_block() is from 4.16+ (581c1760415c4). The fix is to replace 0 by 'gen'. Fixes: 5bdd3536cbbe ("Btrfs: Fix block generation verification race") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Liu Bo <bo.liu(a)linux.alibaba.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 63488f0b850f..8c68961925b1 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2436,10 +2436,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, if (p->reada != READA_NONE) reada_for_search(fs_info, p, level, slot, key->objectid); - btrfs_release_path(p); - ret = -EAGAIN; - tmp = read_tree_block(fs_info, blocknr, 0, parent_level - 1, + tmp = read_tree_block(fs_info, blocknr, gen, parent_level - 1, &first_key); if (!IS_ERR(tmp)) { /* @@ -2454,6 +2452,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, } else { ret = PTR_ERR(tmp); } + + btrfs_release_path(p); return ret; }

7 years, 5 months

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FAILED: patch "[PATCH] btrfs: fix reading stale metadata blocks after degraded raid1" failed to apply to 4.16-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 02a3307aa9c20b4f6626255b028f07f6cfa16feb Mon Sep 17 00:00:00 2001 From: Liu Bo <bo.liu(a)linux.alibaba.com> Date: Wed, 16 May 2018 01:37:36 +0800 Subject: [PATCH] btrfs: fix reading stale metadata blocks after degraded raid1 mounts If a btree block, aka. extent buffer, is not available in the extent buffer cache, it'll be read out from the disk instead, i.e. btrfs_search_slot() read_block_for_search() # hold parent and its lock, go to read child btrfs_release_path() read_tree_block() # read child Unfortunately, the parent lock got released before reading child, so commit 5bdd3536cbbe ("Btrfs: Fix block generation verification race") had used 0 as parent transid to read the child block. It forces read_tree_block() not to check if parent transid is different with the generation id of the child that it reads out from disk. A simple PoC is included in btrfs/124, 0. A two-disk raid1 btrfs, 1. Right after mkfs.btrfs, block A is allocated to be device tree's root. 2. Mount this filesystem and put it in use, after a while, device tree's root got COW but block A hasn't been allocated/overwritten yet. 3. Umount it and reload the btrfs module to remove both disks from the global @fs_devices list. 4. mount -odegraded dev1 and write some data, so now block A is allocated to be a leaf in checksum tree. Note that only dev1 has the latest metadata of this filesystem. 5. Umount it and mount it again normally (with both disks), since raid1 can pick up one disk by the writer task's pid, if btrfs_search_slot() needs to read block A, dev2 which does NOT have the latest metadata might be read for block A, then we got a stale block A. 6. As parent transid is not checked, block A is marked as uptodate and put into the extent buffer cache, so the future search won't bother to read disk again, which means it'll make changes on this stale one and make it dirty and flush it onto disk. To avoid the problem, parent transid needs to be passed to read_tree_block(). In order to get a valid parent transid, we need to hold the parent's lock until finishing reading child. This patch needs to be slightly adapted for stable kernels, the &first_key parameter added to read_tree_block() is from 4.16+ (581c1760415c4). The fix is to replace 0 by 'gen'. Fixes: 5bdd3536cbbe ("Btrfs: Fix block generation verification race") CC: stable(a)vger.kernel.org # 4.4+ Signed-off-by: Liu Bo <bo.liu(a)linux.alibaba.com> Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Reviewed-by: Qu Wenruo <wqu(a)suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 63488f0b850f..8c68961925b1 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2436,10 +2436,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, if (p->reada != READA_NONE) reada_for_search(fs_info, p, level, slot, key->objectid); - btrfs_release_path(p); - ret = -EAGAIN; - tmp = read_tree_block(fs_info, blocknr, 0, parent_level - 1, + tmp = read_tree_block(fs_info, blocknr, gen, parent_level - 1, &first_key); if (!IS_ERR(tmp)) { /* @@ -2454,6 +2452,8 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, } else { ret = PTR_ERR(tmp); } + + btrfs_release_path(p); return ret; }

7 years, 5 months

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FAILED: patch "[PATCH] Btrfs: fix duplicate extents after fsync of file with" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 31d11b83b96faaee4bb514d375a09489117c3e8d Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 9 May 2018 16:01:46 +0100 Subject: [PATCH] Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable(a)vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c1509547c762..8f23a94dab77 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4320,6 +4320,110 @@ static int log_one_extent(struct btrfs_trans_handle *trans, return ret; } +/* + * Log all prealloc extents beyond the inode's i_size to make sure we do not + * lose them after doing a fast fsync and replaying the log. We scan the + * subvolume's root instead of iterating the inode's extent map tree because + * otherwise we can log incorrect extent items based on extent map conversion. + * That can happen due to the fact that extent maps are merged when they + * are not in the extent map tree's list of modified extents. + */ +static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key; + const u64 i_size = i_size_read(&inode->vfs_inode); + const u64 ino = btrfs_ino(inode); + struct btrfs_path *dst_path = NULL; + u64 last_extent = (u64)-1; + int ins_nr = 0; + int start_slot; + int ret; + + if (!(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = i_size; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + &last_extent, start_slot, + ins_nr, 1, 0); + if (ret < 0) + goto out; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid > ino) + break; + if (WARN_ON_ONCE(key.objectid < ino) || + key.type < BTRFS_EXTENT_DATA_KEY || + key.offset < i_size) { + path->slots[0]++; + continue; + } + if (last_extent == (u64)-1) { + last_extent = key.offset; + /* + * Avoid logging extent items logged in past fsync calls + * and leading to duplicate keys in the log tree. + */ + do { + ret = btrfs_truncate_inode_items(trans, + root->log_root, + &inode->vfs_inode, + i_size, + BTRFS_EXTENT_DATA_KEY); + } while (ret == -EAGAIN); + if (ret) + goto out; + } + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + if (!dst_path) { + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + } + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, &last_extent, + start_slot, ins_nr, 1, 0); + if (ret > 0) + ret = 0; + } +out: + btrfs_release_path(path); + btrfs_free_path(dst_path); + return ret; +} + static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, @@ -4362,6 +4466,11 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, if (em->generation <= test_gen) continue; + /* We log prealloc extents beyond eof later. */ + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && + em->start >= i_size_read(&inode->vfs_inode)) + continue; + if (em->start < logged_start) logged_start = em->start; if ((em->start + em->len - 1) > logged_end) @@ -4374,31 +4483,6 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, num++; } - /* - * Add all prealloc extents beyond the inode's i_size to make sure we - * don't lose them after doing a fast fsync and replaying the log. - */ - if (inode->flags & BTRFS_INODE_PREALLOC) { - struct rb_node *node; - - for (node = rb_last(&tree->map); node; node = rb_prev(node)) { - em = rb_entry(node, struct extent_map, rb_node); - if (em->start < i_size_read(&inode->vfs_inode)) - break; - if (!list_empty(&em->list)) - continue; - /* Same as above loop. */ - if (++num > 32768) { - list_del_init(&tree->modified_extents); - ret = -EFBIG; - goto process; - } - refcount_inc(&em->refs); - set_bit(EXTENT_FLAG_LOGGING, &em->flags); - list_add_tail(&em->list, &extents); - } - } - list_sort(NULL, &extents, extent_cmp); btrfs_get_logged_extents(inode, logged_list, logged_start, logged_end); /* @@ -4443,6 +4527,9 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, up_write(&inode->dio_sem); btrfs_release_path(path); + if (!ret) + ret = btrfs_log_prealloc_extents(trans, inode, path); + return ret; }

7 years, 5 months

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FAILED: patch "[PATCH] Btrfs: fix duplicate extents after fsync of file with" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 31d11b83b96faaee4bb514d375a09489117c3e8d Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 9 May 2018 16:01:46 +0100 Subject: [PATCH] Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable(a)vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c1509547c762..8f23a94dab77 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4320,6 +4320,110 @@ static int log_one_extent(struct btrfs_trans_handle *trans, return ret; } +/* + * Log all prealloc extents beyond the inode's i_size to make sure we do not + * lose them after doing a fast fsync and replaying the log. We scan the + * subvolume's root instead of iterating the inode's extent map tree because + * otherwise we can log incorrect extent items based on extent map conversion. + * That can happen due to the fact that extent maps are merged when they + * are not in the extent map tree's list of modified extents. + */ +static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key; + const u64 i_size = i_size_read(&inode->vfs_inode); + const u64 ino = btrfs_ino(inode); + struct btrfs_path *dst_path = NULL; + u64 last_extent = (u64)-1; + int ins_nr = 0; + int start_slot; + int ret; + + if (!(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = i_size; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + &last_extent, start_slot, + ins_nr, 1, 0); + if (ret < 0) + goto out; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid > ino) + break; + if (WARN_ON_ONCE(key.objectid < ino) || + key.type < BTRFS_EXTENT_DATA_KEY || + key.offset < i_size) { + path->slots[0]++; + continue; + } + if (last_extent == (u64)-1) { + last_extent = key.offset; + /* + * Avoid logging extent items logged in past fsync calls + * and leading to duplicate keys in the log tree. + */ + do { + ret = btrfs_truncate_inode_items(trans, + root->log_root, + &inode->vfs_inode, + i_size, + BTRFS_EXTENT_DATA_KEY); + } while (ret == -EAGAIN); + if (ret) + goto out; + } + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + if (!dst_path) { + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + } + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, &last_extent, + start_slot, ins_nr, 1, 0); + if (ret > 0) + ret = 0; + } +out: + btrfs_release_path(path); + btrfs_free_path(dst_path); + return ret; +} + static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, @@ -4362,6 +4466,11 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, if (em->generation <= test_gen) continue; + /* We log prealloc extents beyond eof later. */ + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && + em->start >= i_size_read(&inode->vfs_inode)) + continue; + if (em->start < logged_start) logged_start = em->start; if ((em->start + em->len - 1) > logged_end) @@ -4374,31 +4483,6 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, num++; } - /* - * Add all prealloc extents beyond the inode's i_size to make sure we - * don't lose them after doing a fast fsync and replaying the log. - */ - if (inode->flags & BTRFS_INODE_PREALLOC) { - struct rb_node *node; - - for (node = rb_last(&tree->map); node; node = rb_prev(node)) { - em = rb_entry(node, struct extent_map, rb_node); - if (em->start < i_size_read(&inode->vfs_inode)) - break; - if (!list_empty(&em->list)) - continue; - /* Same as above loop. */ - if (++num > 32768) { - list_del_init(&tree->modified_extents); - ret = -EFBIG; - goto process; - } - refcount_inc(&em->refs); - set_bit(EXTENT_FLAG_LOGGING, &em->flags); - list_add_tail(&em->list, &extents); - } - } - list_sort(NULL, &extents, extent_cmp); btrfs_get_logged_extents(inode, logged_list, logged_start, logged_end); /* @@ -4443,6 +4527,9 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, up_write(&inode->dio_sem); btrfs_release_path(path); + if (!ret) + ret = btrfs_log_prealloc_extents(trans, inode, path); + return ret; }

7 years, 5 months

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FAILED: patch "[PATCH] Btrfs: fix duplicate extents after fsync of file with" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 31d11b83b96faaee4bb514d375a09489117c3e8d Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 9 May 2018 16:01:46 +0100 Subject: [PATCH] Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable(a)vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c1509547c762..8f23a94dab77 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4320,6 +4320,110 @@ static int log_one_extent(struct btrfs_trans_handle *trans, return ret; } +/* + * Log all prealloc extents beyond the inode's i_size to make sure we do not + * lose them after doing a fast fsync and replaying the log. We scan the + * subvolume's root instead of iterating the inode's extent map tree because + * otherwise we can log incorrect extent items based on extent map conversion. + * That can happen due to the fact that extent maps are merged when they + * are not in the extent map tree's list of modified extents. + */ +static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key; + const u64 i_size = i_size_read(&inode->vfs_inode); + const u64 ino = btrfs_ino(inode); + struct btrfs_path *dst_path = NULL; + u64 last_extent = (u64)-1; + int ins_nr = 0; + int start_slot; + int ret; + + if (!(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = i_size; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + &last_extent, start_slot, + ins_nr, 1, 0); + if (ret < 0) + goto out; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid > ino) + break; + if (WARN_ON_ONCE(key.objectid < ino) || + key.type < BTRFS_EXTENT_DATA_KEY || + key.offset < i_size) { + path->slots[0]++; + continue; + } + if (last_extent == (u64)-1) { + last_extent = key.offset; + /* + * Avoid logging extent items logged in past fsync calls + * and leading to duplicate keys in the log tree. + */ + do { + ret = btrfs_truncate_inode_items(trans, + root->log_root, + &inode->vfs_inode, + i_size, + BTRFS_EXTENT_DATA_KEY); + } while (ret == -EAGAIN); + if (ret) + goto out; + } + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + if (!dst_path) { + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + } + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, &last_extent, + start_slot, ins_nr, 1, 0); + if (ret > 0) + ret = 0; + } +out: + btrfs_release_path(path); + btrfs_free_path(dst_path); + return ret; +} + static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, @@ -4362,6 +4466,11 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, if (em->generation <= test_gen) continue; + /* We log prealloc extents beyond eof later. */ + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && + em->start >= i_size_read(&inode->vfs_inode)) + continue; + if (em->start < logged_start) logged_start = em->start; if ((em->start + em->len - 1) > logged_end) @@ -4374,31 +4483,6 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, num++; } - /* - * Add all prealloc extents beyond the inode's i_size to make sure we - * don't lose them after doing a fast fsync and replaying the log. - */ - if (inode->flags & BTRFS_INODE_PREALLOC) { - struct rb_node *node; - - for (node = rb_last(&tree->map); node; node = rb_prev(node)) { - em = rb_entry(node, struct extent_map, rb_node); - if (em->start < i_size_read(&inode->vfs_inode)) - break; - if (!list_empty(&em->list)) - continue; - /* Same as above loop. */ - if (++num > 32768) { - list_del_init(&tree->modified_extents); - ret = -EFBIG; - goto process; - } - refcount_inc(&em->refs); - set_bit(EXTENT_FLAG_LOGGING, &em->flags); - list_add_tail(&em->list, &extents); - } - } - list_sort(NULL, &extents, extent_cmp); btrfs_get_logged_extents(inode, logged_list, logged_start, logged_end); /* @@ -4443,6 +4527,9 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, up_write(&inode->dio_sem); btrfs_release_path(path); + if (!ret) + ret = btrfs_log_prealloc_extents(trans, inode, path); + return ret; }

7 years, 5 months

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0
0 0

FAILED: patch "[PATCH] Btrfs: fix duplicate extents after fsync of file with" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 31d11b83b96faaee4bb514d375a09489117c3e8d Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 9 May 2018 16:01:46 +0100 Subject: [PATCH] Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable(a)vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c1509547c762..8f23a94dab77 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4320,6 +4320,110 @@ static int log_one_extent(struct btrfs_trans_handle *trans, return ret; } +/* + * Log all prealloc extents beyond the inode's i_size to make sure we do not + * lose them after doing a fast fsync and replaying the log. We scan the + * subvolume's root instead of iterating the inode's extent map tree because + * otherwise we can log incorrect extent items based on extent map conversion. + * That can happen due to the fact that extent maps are merged when they + * are not in the extent map tree's list of modified extents. + */ +static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key; + const u64 i_size = i_size_read(&inode->vfs_inode); + const u64 ino = btrfs_ino(inode); + struct btrfs_path *dst_path = NULL; + u64 last_extent = (u64)-1; + int ins_nr = 0; + int start_slot; + int ret; + + if (!(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = i_size; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + &last_extent, start_slot, + ins_nr, 1, 0); + if (ret < 0) + goto out; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid > ino) + break; + if (WARN_ON_ONCE(key.objectid < ino) || + key.type < BTRFS_EXTENT_DATA_KEY || + key.offset < i_size) { + path->slots[0]++; + continue; + } + if (last_extent == (u64)-1) { + last_extent = key.offset; + /* + * Avoid logging extent items logged in past fsync calls + * and leading to duplicate keys in the log tree. + */ + do { + ret = btrfs_truncate_inode_items(trans, + root->log_root, + &inode->vfs_inode, + i_size, + BTRFS_EXTENT_DATA_KEY); + } while (ret == -EAGAIN); + if (ret) + goto out; + } + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + if (!dst_path) { + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + } + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, &last_extent, + start_slot, ins_nr, 1, 0); + if (ret > 0) + ret = 0; + } +out: + btrfs_release_path(path); + btrfs_free_path(dst_path); + return ret; +} + static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, @@ -4362,6 +4466,11 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, if (em->generation <= test_gen) continue; + /* We log prealloc extents beyond eof later. */ + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && + em->start >= i_size_read(&inode->vfs_inode)) + continue; + if (em->start < logged_start) logged_start = em->start; if ((em->start + em->len - 1) > logged_end) @@ -4374,31 +4483,6 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, num++; } - /* - * Add all prealloc extents beyond the inode's i_size to make sure we - * don't lose them after doing a fast fsync and replaying the log. - */ - if (inode->flags & BTRFS_INODE_PREALLOC) { - struct rb_node *node; - - for (node = rb_last(&tree->map); node; node = rb_prev(node)) { - em = rb_entry(node, struct extent_map, rb_node); - if (em->start < i_size_read(&inode->vfs_inode)) - break; - if (!list_empty(&em->list)) - continue; - /* Same as above loop. */ - if (++num > 32768) { - list_del_init(&tree->modified_extents); - ret = -EFBIG; - goto process; - } - refcount_inc(&em->refs); - set_bit(EXTENT_FLAG_LOGGING, &em->flags); - list_add_tail(&em->list, &extents); - } - } - list_sort(NULL, &extents, extent_cmp); btrfs_get_logged_extents(inode, logged_list, logged_start, logged_end); /* @@ -4443,6 +4527,9 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, up_write(&inode->dio_sem); btrfs_release_path(path); + if (!ret) + ret = btrfs_log_prealloc_extents(trans, inode, path); + return ret; }

7 years, 5 months

1
0
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FAILED: patch "[PATCH] Btrfs: fix duplicate extents after fsync of file with" failed to apply to 4.16-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 31d11b83b96faaee4bb514d375a09489117c3e8d Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Wed, 9 May 2018 16:01:46 +0100 Subject: [PATCH] Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable(a)vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index c1509547c762..8f23a94dab77 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4320,6 +4320,110 @@ static int log_one_extent(struct btrfs_trans_handle *trans, return ret; } +/* + * Log all prealloc extents beyond the inode's i_size to make sure we do not + * lose them after doing a fast fsync and replaying the log. We scan the + * subvolume's root instead of iterating the inode's extent map tree because + * otherwise we can log incorrect extent items based on extent map conversion. + * That can happen due to the fact that extent maps are merged when they + * are not in the extent map tree's list of modified extents. + */ +static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key; + const u64 i_size = i_size_read(&inode->vfs_inode); + const u64 ino = btrfs_ino(inode); + struct btrfs_path *dst_path = NULL; + u64 last_extent = (u64)-1; + int ins_nr = 0; + int start_slot; + int ret; + + if (!(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = i_size; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + &last_extent, start_slot, + ins_nr, 1, 0); + if (ret < 0) + goto out; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid > ino) + break; + if (WARN_ON_ONCE(key.objectid < ino) || + key.type < BTRFS_EXTENT_DATA_KEY || + key.offset < i_size) { + path->slots[0]++; + continue; + } + if (last_extent == (u64)-1) { + last_extent = key.offset; + /* + * Avoid logging extent items logged in past fsync calls + * and leading to duplicate keys in the log tree. + */ + do { + ret = btrfs_truncate_inode_items(trans, + root->log_root, + &inode->vfs_inode, + i_size, + BTRFS_EXTENT_DATA_KEY); + } while (ret == -EAGAIN); + if (ret) + goto out; + } + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + if (!dst_path) { + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + } + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, &last_extent, + start_slot, ins_nr, 1, 0); + if (ret > 0) + ret = 0; + } +out: + btrfs_release_path(path); + btrfs_free_path(dst_path); + return ret; +} + static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_inode *inode, @@ -4362,6 +4466,11 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, if (em->generation <= test_gen) continue; + /* We log prealloc extents beyond eof later. */ + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && + em->start >= i_size_read(&inode->vfs_inode)) + continue; + if (em->start < logged_start) logged_start = em->start; if ((em->start + em->len - 1) > logged_end) @@ -4374,31 +4483,6 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, num++; } - /* - * Add all prealloc extents beyond the inode's i_size to make sure we - * don't lose them after doing a fast fsync and replaying the log. - */ - if (inode->flags & BTRFS_INODE_PREALLOC) { - struct rb_node *node; - - for (node = rb_last(&tree->map); node; node = rb_prev(node)) { - em = rb_entry(node, struct extent_map, rb_node); - if (em->start < i_size_read(&inode->vfs_inode)) - break; - if (!list_empty(&em->list)) - continue; - /* Same as above loop. */ - if (++num > 32768) { - list_del_init(&tree->modified_extents); - ret = -EFBIG; - goto process; - } - refcount_inc(&em->refs); - set_bit(EXTENT_FLAG_LOGGING, &em->flags); - list_add_tail(&em->list, &extents); - } - } - list_sort(NULL, &extents, extent_cmp); btrfs_get_logged_extents(inode, logged_list, logged_start, logged_end); /* @@ -4443,6 +4527,9 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, up_write(&inode->dio_sem); btrfs_release_path(path); + if (!ret) + ret = btrfs_log_prealloc_extents(trans, inode, path); + return ret; }

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