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xfs: reallocate realtime summary cache on growfs

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At mount time, we allocate m_rsum_cache with the number of realtime
bitmap blocks. However, xfs_growfs_rt() can increase the number of
realtime bitmap blocks. Using the cache after this happens may access
out of the bounds of the cache. Fix it by reallocating the cache in this
case.

Fixes: 355e353213 ("xfs: cache minimum realtime summary level")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Omar Sandoval 2018-12-21 18:45:18 -08:00 committed by Darrick J. Wong
parent 86d163dbfe
commit 65eed012d1
1 changed files with 36 additions and 8 deletions
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44
fs/xfs/xfs_rtalloc.c
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@ -861,6 +861,21 @@ out_trans_cancel:
return error;
}
static void
xfs_alloc_rsum_cache(
xfs_mount_t *mp, /* file system mount structure */
xfs_extlen_t rbmblocks) /* number of rt bitmap blocks */
{
/*
* The rsum cache is initialized to all zeroes, which is trivially a
* lower bound on the minimum level with any free extents. We can
* continue without the cache if it couldn't be allocated.
*/
mp->m_rsum_cache = kmem_zalloc_large(rbmblocks, KM_SLEEP);
if (!mp->m_rsum_cache)
xfs_warn(mp, "could not allocate realtime summary cache");
}
/*
* Visible (exported) functions.
*/
@ -889,6 +904,7 @@ xfs_growfs_rt(
xfs_extlen_t rsumblocks; /* current number of rt summary blks */
xfs_sb_t *sbp; /* old superblock */
xfs_fsblock_t sumbno; /* summary block number */
uint8_t *rsum_cache; /* old summary cache */
sbp = &mp->m_sb;
/*
@ -945,6 +961,11 @@ xfs_growfs_rt(
error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip);
if (error)
return error;
rsum_cache = mp->m_rsum_cache;
if (nrbmblocks != sbp->sb_rbmblocks)
xfs_alloc_rsum_cache(mp, nrbmblocks);
/*
* Allocate a new (fake) mount/sb.
*/
@ -1070,6 +1091,20 @@ error_cancel:
*/
kmem_free(nmp);
/*
* If we had to allocate a new rsum_cache, we either need to free the
* old one (if we succeeded) or free the new one and restore the old one
* (if there was an error).
*/
if (rsum_cache != mp->m_rsum_cache) {
if (error) {
kmem_free(mp->m_rsum_cache);
mp->m_rsum_cache = rsum_cache;
} else {
kmem_free(rsum_cache);
}
}
return error;
}
@ -1217,14 +1252,7 @@ xfs_rtmount_inodes(
return error;
}
ASSERT(mp->m_rsumip != NULL);
/*
* The rsum cache is initialized to all zeroes, which is trivially a
* lower bound on the minimum level with any free extents. We can
* continue without the cache if it couldn't be allocated.
*/
mp->m_rsum_cache = kmem_zalloc_large(sbp->sb_rbmblocks, KM_SLEEP);
if (!mp->m_rsum_cache)
xfs_warn(mp, "could not allocate realtime summary cache");
xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks);
return 0;
}