6.15-stable review patch. If anyone has any objections, please let me know.
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From: Chao Yu chao@kernel.org
[ Upstream commit aa1be8dd64163eca4dde7fd2557eb19927a06a47 ]
Jan Prusakowski reported a f2fs bug as below:
f2fs/007 will hang kernel during testing w/ below configs:
kernel 6.12.18 (from pixel-kernel/android16-6.12) export MKFS_OPTIONS="-O encrypt -O extra_attr -O project_quota -O quota" export F2FS_MOUNT_OPTIONS="test_dummy_encryption,discard,fsync_mode=nobarrier,reserve_root=32768,checkpoint_merge,atgc"
cat /proc/<umount_proc_id>/stack f2fs_wait_on_all_pages+0xa3/0x130 do_checkpoint+0x40c/0x5d0 f2fs_write_checkpoint+0x258/0x550 kill_f2fs_super+0x14f/0x190 deactivate_locked_super+0x30/0xb0 cleanup_mnt+0xba/0x150 task_work_run+0x59/0xa0 syscall_exit_to_user_mode+0x12d/0x130 do_syscall_64+0x57/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e
cat /sys/kernel/debug/f2fs/status
- IO_W (CP: -256, Data: 256, Flush: ( 0 0 1), Discard: ( 0 0)) cmd: 0 undiscard: 0
CP IOs reference count becomes negative.
The root cause is:
After 4961acdd65c9 ("f2fs: fix to tag gcing flag on page during block migration"), we will tag page w/ gcing flag for raw page of cluster during its migration.
However, if the inode is both encrypted and compressed, during ioc_decompress(), it will tag page w/ gcing flag, and it increase F2FS_WB_DATA reference count: - f2fs_write_multi_page - f2fs_write_raw_page - f2fs_write_single_page - do_write_page - f2fs_submit_page_write - WB_DATA_TYPE(bio_page, fio->compressed_page) : bio_page is encrypted, so mapping is NULL, and fio->compressed_page is NULL, it returns F2FS_WB_DATA - inc_page_count(.., F2FS_WB_DATA)
Then, during end_io(), it decrease F2FS_WB_CP_DATA reference count: - f2fs_write_end_io - f2fs_compress_write_end_io - fscrypt_pagecache_folio : get raw page from encrypted page - WB_DATA_TYPE(&folio->page, false) : raw page has gcing flag, it returns F2FS_WB_CP_DATA - dec_page_count(.., F2FS_WB_CP_DATA)
In order to fix this issue, we need to detect gcing flag in raw page in f2fs_is_cp_guaranteed().
Fixes: 4961acdd65c9 ("f2fs: fix to tag gcing flag on page during block migration") Reported-by: Jan Prusakowski jprusakowski@google.com 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 5a7888a5923ca..81b25dd15a0b9 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -54,7 +54,7 @@ bool f2fs_is_cp_guaranteed(struct page *page) struct f2fs_sb_info *sbi;
if (fscrypt_is_bounce_page(page)) - return false; + return page_private_gcing(fscrypt_pagecache_page(page));
inode = mapping->host; sbi = F2FS_I_SB(inode);