6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chao Yu chao@kernel.org
[ Upstream commit ba8dac350faf16afc129ce6303ca4feaf083ccb1 ]
fstest reports a f2fs bug:
#generic/363 42s ... [failed, exit status 1]- output mismatch (see /share/git/fstests/results//generic/363.out.bad) # --- tests/generic/363.out 2025-01-12 21:57:40.271440542 +0800 # +++ /share/git/fstests/results//generic/363.out.bad 2025-05-19 19:55:58.000000000 +0800 # @@ -1,2 +1,78 @@ # QA output created by 363 # fsx -q -S 0 -e 1 -N 100000 # +READ BAD DATA: offset = 0xd6fb, size = 0xf044, fname = /mnt/f2fs/junk # +OFFSET GOOD BAD RANGE # +0x1540d 0x0000 0x2a25 0x0 # +operation# (mod 256) for the bad data may be 37 # +0x1540e 0x0000 0x2527 0x1 # ... # (Run 'diff -u /share/git/fstests/tests/generic/363.out /share/git/fstests/results//generic/363.out.bad' to see the entire diff) Ran: generic/363 Failures: generic/363 Failed 1 of 1 tests
The root cause is user can update post-eof page via mmap [1], however, f2fs missed to zero post-eof page in below operations, so, once it expands i_size, then it will include dummy data locates previous post-eof page, so during below operations, we need to zero post-eof page.
Operations which can include dummy data after previous i_size after expanding i_size: - write - mapwrite [1] - truncate - fallocate * preallocate * zero_range * insert_range * collapse_range - clone_range (doesn’t support in f2fs) - copy_range (doesn’t support in f2fs)
[1] https://man7.org/linux/man-pages/man2/mmap.2.html 'BUG section'
Cc: stable@kernel.org Signed-off-by: Chao Yu chao@kernel.org Reviewed-by: Zhiguo Niu zhiguo.niu@unisoc.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/file.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 121849a4dcfda..b73d40f981916 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -36,6 +36,17 @@ #include <trace/events/f2fs.h> #include <uapi/linux/f2fs.h>
+static void f2fs_zero_post_eof_page(struct inode *inode, loff_t new_size) +{ + loff_t old_size = i_size_read(inode); + + if (old_size >= new_size) + return; + + /* zero or drop pages only in range of [old_size, new_size] */ + truncate_pagecache(inode, old_size); +} + static vm_fault_t f2fs_filemap_fault(struct vm_fault *vmf) { struct inode *inode = file_inode(vmf->vma->vm_file); @@ -103,8 +114,13 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
+ filemap_invalidate_lock(inode->i_mapping); + f2fs_zero_post_eof_page(inode, (folio->index + 1) << PAGE_SHIFT); + filemap_invalidate_unlock(inode->i_mapping); + file_update_time(vmf->vma->vm_file); filemap_invalidate_lock_shared(inode->i_mapping); + folio_lock(folio); if (unlikely(folio->mapping != inode->i_mapping || folio_pos(folio) > i_size_read(inode) || @@ -1051,6 +1067,8 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry, f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); filemap_invalidate_lock(inode->i_mapping);
+ if (attr->ia_size > old_size) + f2fs_zero_post_eof_page(inode, attr->ia_size); truncate_setsize(inode, attr->ia_size);
if (attr->ia_size <= old_size) @@ -1169,6 +1187,10 @@ static int f2fs_punch_hole(struct inode *inode, loff_t offset, loff_t len) if (ret) return ret;
+ filemap_invalidate_lock(inode->i_mapping); + f2fs_zero_post_eof_page(inode, offset + len); + filemap_invalidate_unlock(inode->i_mapping); + pg_start = ((unsigned long long) offset) >> PAGE_SHIFT; pg_end = ((unsigned long long) offset + len) >> PAGE_SHIFT;
@@ -1453,6 +1475,8 @@ static int f2fs_do_collapse(struct inode *inode, loff_t offset, loff_t len) f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); filemap_invalidate_lock(inode->i_mapping);
+ f2fs_zero_post_eof_page(inode, offset + len); + f2fs_lock_op(sbi); f2fs_drop_extent_tree(inode); truncate_pagecache(inode, offset); @@ -1575,6 +1599,10 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len, if (ret) return ret;
+ filemap_invalidate_lock(mapping); + f2fs_zero_post_eof_page(inode, offset + len); + filemap_invalidate_unlock(mapping); + pg_start = ((unsigned long long) offset) >> PAGE_SHIFT; pg_end = ((unsigned long long) offset + len) >> PAGE_SHIFT;
@@ -1706,6 +1734,8 @@ static int f2fs_insert_range(struct inode *inode, loff_t offset, loff_t len) /* avoid gc operation during block exchange */ f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); filemap_invalidate_lock(mapping); + + f2fs_zero_post_eof_page(inode, offset + len); truncate_pagecache(inode, offset);
while (!ret && idx > pg_start) { @@ -1761,6 +1791,10 @@ static int f2fs_expand_inode_data(struct inode *inode, loff_t offset, if (err) return err;
+ filemap_invalidate_lock(inode->i_mapping); + f2fs_zero_post_eof_page(inode, offset + len); + filemap_invalidate_unlock(inode->i_mapping); + f2fs_balance_fs(sbi, true);
pg_start = ((unsigned long long)offset) >> PAGE_SHIFT; @@ -4674,6 +4708,10 @@ static ssize_t f2fs_write_checks(struct kiocb *iocb, struct iov_iter *from) err = file_modified(file); if (err) return err; + + filemap_invalidate_lock(inode->i_mapping); + f2fs_zero_post_eof_page(inode, iocb->ki_pos + iov_iter_count(from)); + filemap_invalidate_unlock(inode->i_mapping); return count; }