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/extents.c b/fs/ext4/extents.c
index 1ba8b4a..d86d262 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4456,6 +4456,8 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
                ar.flags |= EXT4_MB_HINT_NOPREALLOC;
        if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
                ar.flags |= EXT4_MB_DELALLOC_RESERVED;
+       if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+               ar.flags |= EXT4_MB_USE_RESERVED;
        newblock = ext4_mb_new_blocks(handle, &ar, &err);
        if (!newblock)
                goto out2;

diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index 9588240..9962d57 100644 (file)
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -576,6 +576,8 @@ int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
                ar.flags = EXT4_MB_HINT_DATA;
        if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
                ar.flags |= EXT4_MB_DELALLOC_RESERVED;
+       if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+               ar.flags |= EXT4_MB_USE_RESERVED;
 
        ar.goal = ext4_find_goal(inode, map->m_lblk, partial);
 

diff --cc fs/ext4/inode.c
Simple merge

diff --cc fs/ext4/namei.c
Simple merge

diff --cc fs/ext4/super.c
Simple merge