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>
This commit is contained in:
Theodore Ts'o 2015-06-21 01:25:29 -04:00
parent 89d96a6f8e
commit c5e298ae53
5 changed files with 17 additions and 7 deletions

View File

@ -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;

View File

@ -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);

View File

@ -731,18 +731,18 @@ int ext4_get_block(struct inode *inode, sector_t iblock,
* `handle' can be NULL if create is zero
*/
struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
ext4_lblk_t block, int create)
ext4_lblk_t block, int map_flags)
{
struct ext4_map_blocks map;
struct buffer_head *bh;
int create = map_flags & EXT4_GET_BLOCKS_CREATE;
int err;
J_ASSERT(handle != NULL || create == 0);
map.m_lblk = block;
map.m_len = 1;
err = ext4_map_blocks(handle, inode, &map,
create ? EXT4_GET_BLOCKS_CREATE : 0);
err = ext4_map_blocks(handle, inode, &map, map_flags);
if (err == 0)
return create ? ERR_PTR(-ENOSPC) : NULL;
@ -788,11 +788,11 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
}
struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
ext4_lblk_t block, int create)
ext4_lblk_t block, int map_flags)
{
struct buffer_head *bh;
bh = ext4_getblk(handle, inode, block, create);
bh = ext4_getblk(handle, inode, block, map_flags);
if (IS_ERR(bh))
return bh;
if (!bh || buffer_uptodate(bh))

View File

@ -61,7 +61,7 @@ static struct buffer_head *ext4_append(handle_t *handle,
*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
bh = ext4_bread(handle, inode, *block, 1);
bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
if (IS_ERR(bh))
return bh;
inode->i_size += inode->i_sb->s_blocksize;

View File

@ -5438,6 +5438,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
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 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
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)