We got issue as follows: WARNING: CPU: 2 PID: 1936 at fs/ext4/inode.c:1511 ext4_da_release_space+0x1b9/0x266 Modules linked in: CPU: 2 PID: 1936 Comm: dd Not tainted 5.10.0+ #344 RIP: 0010:ext4_da_release_space+0x1b9/0x266 RSP: 0018:ffff888127307848 EFLAGS: 00010292 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff843f67cc RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffed1024e60ed9 RBP: ffff888124dc8140 R08: 0000000000000083 R09: ffffed1075da6d23 R10: ffff8883aed36917 R11: ffffed1075da6d22 R12: ffff888124dc83f0 R13: ffff888124dc844c R14: ffff888124dc8168 R15: 000000000000000c FS: 00007f6b7247d740(0000) GS:ffff8883aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc1a0b7dd8 CR3: 00000001065ce000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_es_remove_extent+0x187/0x230 mpage_release_unused_pages+0x3af/0x470 ext4_writepages+0xb9b/0x1160 do_writepages+0xbb/0x1e0 __filemap_fdatawrite_range+0x1b1/0x1f0 file_write_and_wait_range+0x80/0xe0 ext4_sync_file+0x13d/0x800 vfs_fsync_range+0x75/0x140 do_fsync+0x4d/0x90 __x64_sys_fsync+0x1d/0x30 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Above issue may happens as follows: process1 process2 ext4_da_write_begin ext4_da_reserve_space ext4_es_insert_delayed_block[1/1] ext4_da_write_begin ext4_es_insert_delayed_block[0/1] ext4_writepages ****Delayed block allocation failed**** mpage_release_unused_pages ext4_es_remove_extent[1/1] ext4_da_release_space [reserved 0] ext4_da_write_begin ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk) ->As there exist [0, 1] extent, so will return true ext4_writepages ****Delayed block allocation failed**** mpage_release_unused_pages ext4_es_remove_extent[0/1] ext4_da_release_space [reserved 1] ei->i_reserved_data_blocks [1->0] ext4_es_insert_delayed_block[1/1] ext4_writepages ****Delayed block allocation failed**** mpage_release_unused_pages ext4_es_remove_extent[1/1] ext4_da_release_space [reserved 1] ei->i_reserved_data_blocks[0, -1] ->As ei->i_reserved_data_blocks already is zero but to_free is 1, will trigger warning. To solve above issue, introduce i_clu_lock to protect insert delayed block and remove block under cluster delay allocate mode. Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> --- fs/ext4/ext4.h | 3 +++ fs/ext4/extents_status.c | 5 +++++ fs/ext4/inode.c | 11 +++++++++-- fs/ext4/super.c | 1 + 4 files changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index bcd3b9bf8069..47c88ac4d4a8 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1169,6 +1169,9 @@ struct ext4_inode_info { __u32 i_csum_seed; kprojid_t i_projid; + + /* Protect concurrent add cluster delayed block and remove block */ + struct mutex i_clu_lock; }; /* diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 9a3a8996aacf..dd679014db98 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -1433,6 +1433,7 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk, int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len) { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); ext4_lblk_t end; int err = 0; int reserved = 0; @@ -1455,9 +1456,13 @@ int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk, * so that we are sure __es_shrink() is done with the inode before it * is reclaimed. */ + if (sbi->s_cluster_ratio != 1) + mutex_lock(&EXT4_I(inode)->i_clu_lock); write_lock(&EXT4_I(inode)->i_es_lock); err = __es_remove_extent(inode, lblk, end, &reserved); write_unlock(&EXT4_I(inode)->i_es_lock); + if (sbi->s_cluster_ratio != 1) + mutex_unlock(&EXT4_I(inode)->i_clu_lock); ext4_es_print_tree(inode); ext4_da_release_space(inode, reserved); return err; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 01c9e4f743ba..1109d77ad60b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1649,17 +1649,22 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) goto errout; reserved = true; } else { /* bigalloc */ + mutex_lock(&EXT4_I(inode)->i_clu_lock); if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) { if (!ext4_es_scan_clu(inode, &ext4_es_is_mapped, lblk)) { ret = ext4_clu_mapped(inode, EXT4_B2C(sbi, lblk)); - if (ret < 0) + if (ret < 0) { + mutex_unlock(&EXT4_I(inode)->i_clu_lock); goto errout; + } if (ret == 0) { ret = ext4_da_reserve_space(inode); - if (ret != 0) /* ENOSPC */ + if (ret != 0) { /* ENOSPC */ + mutex_unlock(&EXT4_I(inode)->i_clu_lock); goto errout; + } reserved = true; } else { allocated = true; @@ -1671,6 +1676,8 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk) } ret = ext4_es_insert_delayed_block(inode, lblk, allocated); + if (sbi->s_cluster_ratio != 1) + mutex_unlock(&EXT4_I(inode)->i_clu_lock); if (ret && reserved) ext4_da_release_space(inode, 1); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index c5021ca0a28a..aa6f2a68bf41 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1347,6 +1347,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work); ext4_fc_init_inode(&ei->vfs_inode); mutex_init(&ei->i_fc_lock); + mutex_init(&ei->i_clu_lock); return &ei->vfs_inode; } -- 2.31.1