ext4: prevent ext4_quota_write() from failing due to ENOSPC
In order to prevent quota block tracking to be inaccurate when
ext4_quota_write() fails with ENOSPC, we make two changes. The quota
file can now use the reserved block (since the quota file is arguably
file system metadata), and ext4_quota_write() now uses
ext4_should_retry_alloc() to retry the block allocation after a commit
has completed and released some blocks for allocation.
This fixes failures of xfstests generic/270:
Quota error (device vdc): write_blk: dquota write failed
Quota error (device vdc): qtree_write_dquot: Error -28 occurred while creating quota
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 2858ac0..bd4df9d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5438,6 +5438,7 @@
struct inode *inode = sb_dqopt(sb)->files[type];
ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
int err, offset = off & (sb->s_blocksize - 1);
+ int retries = 0;
struct buffer_head *bh;
handle_t *handle = journal_current_handle();
@@ -5458,7 +5459,12 @@
return -EIO;
}
- bh = ext4_bread(handle, inode, blk, 1);
+ do {
+ bh = ext4_bread(handle, inode, blk,
+ EXT4_GET_BLOCKS_CREATE |
+ EXT4_GET_BLOCKS_METADATA_NOFAIL);
+ } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
+ ext4_should_retry_alloc(inode->i_sb, &retries));
if (IS_ERR(bh))
return PTR_ERR(bh);
if (!bh)