6.6-stable review patch. If anyone has any objections, please let me know.
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From: Chao Yu chao@kernel.org
[ Upstream commit c5d3f9b7649abb20aa5ab3ebff9421a171eaeb22 ]
With below mount option and testcase, it hangs kernel.
1. mount -t f2fs -o compress_log_size=5 /dev/vdb /mnt/f2fs 2. touch /mnt/f2fs/file 3. chattr +c /mnt/f2fs/file 4. dd if=/dev/zero of=/mnt/f2fs/file bs=1MB count=1 5. sync 6. dd if=/dev/zero of=/mnt/f2fs/file bs=111 count=11 conv=notrunc 7. sync
INFO: task sync:4788 blocked for more than 120 seconds. Not tainted 6.5.0-rc1+ #322 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:sync state:D stack:0 pid:4788 ppid:509 flags:0x00000002 Call Trace: <TASK> __schedule+0x335/0xf80 schedule+0x6f/0xf0 wb_wait_for_completion+0x5e/0x90 sync_inodes_sb+0xd8/0x2a0 sync_inodes_one_sb+0x1d/0x30 iterate_supers+0x99/0xf0 ksys_sync+0x46/0xb0 __do_sys_sync+0x12/0x20 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
The reason is f2fs_all_cluster_page_ready() assumes that pages array should cover at least one cluster, otherwise, it will always return false, result in deadloop.
By default, pages array size is 16, and it can cover the case cluster_size is equal or less than 16, for the case cluster_size is larger than 16, let's allocate memory of pages array dynamically.
Fixes: 4c8ff7095bef ("f2fs: support data compression") Signed-off-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/data.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 916e317ac925f..3f33e14dc7f81 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3023,7 +3023,8 @@ static int f2fs_write_cache_pages(struct address_space *mapping, { int ret = 0; int done = 0, retry = 0; - struct page *pages[F2FS_ONSTACK_PAGES]; + struct page *pages_local[F2FS_ONSTACK_PAGES]; + struct page **pages = pages_local; struct folio_batch fbatch; struct f2fs_sb_info *sbi = F2FS_M_SB(mapping); struct bio *bio = NULL; @@ -3047,6 +3048,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping, #endif int nr_folios, p, idx; int nr_pages; + unsigned int max_pages = F2FS_ONSTACK_PAGES; pgoff_t index; pgoff_t end; /* Inclusive */ pgoff_t done_index; @@ -3056,6 +3058,15 @@ static int f2fs_write_cache_pages(struct address_space *mapping, int submitted = 0; int i;
+#ifdef CONFIG_F2FS_FS_COMPRESSION + if (f2fs_compressed_file(inode) && + 1 << cc.log_cluster_size > F2FS_ONSTACK_PAGES) { + pages = f2fs_kzalloc(sbi, sizeof(struct page *) << + cc.log_cluster_size, GFP_NOFS | __GFP_NOFAIL); + max_pages = 1 << cc.log_cluster_size; + } +#endif + folio_batch_init(&fbatch);
if (get_dirty_pages(mapping->host) <= @@ -3101,7 +3112,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping, add_more: pages[nr_pages] = folio_page(folio, idx); folio_get(folio); - if (++nr_pages == F2FS_ONSTACK_PAGES) { + if (++nr_pages == max_pages) { index = folio->index + idx + 1; folio_batch_release(&fbatch); goto write; @@ -3283,6 +3294,11 @@ static int f2fs_write_cache_pages(struct address_space *mapping, if (bio) f2fs_submit_merged_ipu_write(sbi, &bio, NULL);
+#ifdef CONFIG_F2FS_FS_COMPRESSION + if (pages != pages_local) + kfree(pages); +#endif + return ret; }