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| author |   zhangyi (F) <yi.zhang@huawei.com> | 2020-06-20 10:54:23 +0800 |
|---|---|---|
| committer |   Theodore Ts'o <tytso@mit.edu> | 2020-08-07 14:12:34 -0400 |
| commit | bc71726c725767205757821df364acff87f92ac5 (patch) | |
| tree | 091fcc3c180953f83a0e6627902ece509e34f109 /fs/ext4/super.c | |
| parent | ext4: skip non-loaded groups at cr=0/1 when scanning for good groups (diff) | |
| download | linux-dev-bc71726c725767205757821df364acff87f92ac5.tar.xz linux-dev-bc71726c725767205757821df364acff87f92ac5.zip | |
ext4: abort the filesystem if failed to async write metadata buffer
There is a risk of filesystem inconsistency if we failed to async write
back metadata buffer in the background. Because of current buffer's end
io procedure is handled by end_buffer_async_write() in the block layer,
and it only clear the buffer's uptodate flag and mark the write_io_error
flag, so ext4 cannot detect such failure immediately. In most cases of
getting metadata buffer (e.g. ext4_read_inode_bitmap()), although the
buffer's data is actually uptodate, it may still read data from disk
because the buffer's uptodate flag has been cleared. Finally, it may
lead to on-disk filesystem inconsistency if reading old data from the
disk successfully and write them out again.
This patch detect bdev mapping->wb_err when getting journal's write
access and mark the filesystem error if bdev's mapping->wb_err was
increased, this could prevent further writing and potential
inconsistency.
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200620025427.1756360-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index dda967efcbc2..c77b10257b36 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4765,6 +4765,15 @@ no_journal: } #endif /* CONFIG_QUOTA */ + /* + * Save the original bdev mapping's wb_err value which could be + * used to detect the metadata async write error. + */ + spin_lock_init(&sbi->s_bdev_wb_lock); + if (!sb_rdonly(sb)) + errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err, + &sbi->s_bdev_wb_err); + sb->s_bdev->bd_super = sb; EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS; ext4_orphan_cleanup(sb, es); EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS; @@ -5655,6 +5664,14 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) } /* + * Update the original bdev mapping's wb_err value + * which could be used to detect the metadata async + * write error. + */ + errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err, + &sbi->s_bdev_wb_err); + + /* * Mounting a RDONLY partition read-write, so reread * and store the current valid flag. (It may have * been changed by e2fsck since we originally mounted |