6.14-stable review patch. If anyone has any objections, please let me know.
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From: Heming Zhao heming.zhao@suse.com
commit bd1261b16d9131d79723d982d54295e7f309797a upstream.
commit 4eb7b93e0310 ("ocfs2: improve write IO performance when fragmentation is high") introduced another regression.
The following ocfs2-test case can trigger this issue:
discontig_runner.sh => activate_discontig_bg.sh => resv_unwritten: ${RESV_UNWRITTEN_BIN} -f ${WORK_PLACE}/large_testfile -s 0 -l \ $((${FILE_MAJOR_SIZE_M}*1024*1024))
In my env, test disk size (by "fdisk -l <dev>"):
53687091200 bytes, 104857600 sectors.
Above command is:
/usr/local/ocfs2-test/bin/resv_unwritten -f \ /mnt/ocfs2/ocfs2-activate-discontig-bg-dir/large_testfile -s 0 -l \ 53187969024
Error log:
[*] Reserve 50724M space for a LARGE file, reserve 200M space for future test. ioctl error 28: "No space left on device" resv allocation failed Unknown error -1 reserve unwritten region from 0 to 53187969024.
Call flow: __ocfs2_change_file_space //by ioctl OCFS2_IOC_RESVSP64 ocfs2_allocate_unwritten_extents //start:0 len:53187969024 while() + ocfs2_get_clusters //cpos:0, alloc_size:1623168 (cluster number) + ocfs2_extend_allocation + ocfs2_lock_allocators | + choose OCFS2_AC_USE_MAIN & ocfs2_cluster_group_search | + ocfs2_add_inode_data ocfs2_add_clusters_in_btree __ocfs2_claim_clusters ocfs2_claim_suballoc_bits + During the allocation of the final part of the large file (after ~47GB), no chain had the required contiguous bits_wanted. Consequently, the allocation failed.
How to fix: When OCFS2 is encountering fragmented allocation, the file system should stop attempting bits_wanted contiguous allocation and instead provide the largest available contiguous free bits from the cluster groups.
Link: https://lkml.kernel.org/r/20250414060125.19938-2-heming.zhao@suse.com Fixes: 4eb7b93e0310 ("ocfs2: improve write IO performance when fragmentation is high") Signed-off-by: Heming Zhao heming.zhao@suse.com Reported-by: Gautham Ananthakrishna gautham.ananthakrishna@oracle.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Cc: Mark Fasheh mark@fasheh.com Cc: Joel Becker jlbec@evilplan.org Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Changwei Ge gechangwei@live.cn Cc: Jun Piao piaojun@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ocfs2/suballoc.c | 38 ++++++++++++++++++++++++++++++++------ fs/ocfs2/suballoc.h | 1 + 2 files changed, 33 insertions(+), 6 deletions(-)
--- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -698,10 +698,12 @@ static int ocfs2_block_group_alloc(struc
bg_bh = ocfs2_block_group_alloc_contig(osb, handle, alloc_inode, ac, cl); - if (PTR_ERR(bg_bh) == -ENOSPC) + if (PTR_ERR(bg_bh) == -ENOSPC) { + ac->ac_which = OCFS2_AC_USE_MAIN_DISCONTIG; bg_bh = ocfs2_block_group_alloc_discontig(handle, alloc_inode, ac, cl); + } if (IS_ERR(bg_bh)) { status = PTR_ERR(bg_bh); bg_bh = NULL; @@ -1794,6 +1796,7 @@ static int ocfs2_search_chain(struct ocf { int status; u16 chain; + u32 contig_bits; u64 next_group; struct inode *alloc_inode = ac->ac_inode; struct buffer_head *group_bh = NULL; @@ -1819,10 +1822,21 @@ static int ocfs2_search_chain(struct ocf status = -ENOSPC; /* for now, the chain search is a bit simplistic. We just use * the 1st group with any empty bits. */ - while ((status = ac->ac_group_search(alloc_inode, group_bh, - bits_wanted, min_bits, - ac->ac_max_block, - res)) == -ENOSPC) { + while (1) { + if (ac->ac_which == OCFS2_AC_USE_MAIN_DISCONTIG) { + contig_bits = le16_to_cpu(bg->bg_contig_free_bits); + if (!contig_bits) + contig_bits = ocfs2_find_max_contig_free_bits(bg->bg_bitmap, + le16_to_cpu(bg->bg_bits), 0); + if (bits_wanted > contig_bits && contig_bits >= min_bits) + bits_wanted = contig_bits; + } + + status = ac->ac_group_search(alloc_inode, group_bh, + bits_wanted, min_bits, + ac->ac_max_block, res); + if (status != -ENOSPC) + break; if (!bg->bg_next_group) break;
@@ -1982,6 +1996,7 @@ static int ocfs2_claim_suballoc_bits(str victim = ocfs2_find_victim_chain(cl); ac->ac_chain = victim;
+search: status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, res, &bits_left); if (!status) { @@ -2022,6 +2037,16 @@ static int ocfs2_claim_suballoc_bits(str } }
+ /* Chains can't supply the bits_wanted contiguous space. + * We should switch to using every single bit when allocating + * from the global bitmap. */ + if (i == le16_to_cpu(cl->cl_next_free_rec) && + status == -ENOSPC && ac->ac_which == OCFS2_AC_USE_MAIN) { + ac->ac_which = OCFS2_AC_USE_MAIN_DISCONTIG; + ac->ac_chain = victim; + goto search; + } + set_hint: if (status != -ENOSPC) { /* If the next search of this group is not likely to @@ -2365,7 +2390,8 @@ int __ocfs2_claim_clusters(handle_t *han BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL - && ac->ac_which != OCFS2_AC_USE_MAIN); + && ac->ac_which != OCFS2_AC_USE_MAIN + && ac->ac_which != OCFS2_AC_USE_MAIN_DISCONTIG);
if (ac->ac_which == OCFS2_AC_USE_LOCAL) { WARN_ON(min_clusters > 1); --- a/fs/ocfs2/suballoc.h +++ b/fs/ocfs2/suballoc.h @@ -29,6 +29,7 @@ struct ocfs2_alloc_context { #define OCFS2_AC_USE_MAIN 2 #define OCFS2_AC_USE_INODE 3 #define OCFS2_AC_USE_META 4 +#define OCFS2_AC_USE_MAIN_DISCONTIG 5 u32 ac_which;
/* these are used by the chain search */