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authorChristoph Hellwig <hch@infradead.org>2009-07-18 18:14:53 -0400
committerFelix Blyakher <felixb@sgi.com>2009-08-12 01:06:51 -0500
commit0cc6eee130b0c062feec8446d9cecdb17d2cfad3 (patch)
tree488cbdb1fb8623285c4fb7c3a913516d7b7905d2
parentc8a4051c3731b6db224482218cfd535ab9393ff8 (diff)
downloadconfigs-0cc6eee130b0c062feec8446d9cecdb17d2cfad3.tar.gz
xfs: avoid memory allocation under m_peraglock in growfs code
Allocate the memory for the larger m_perag array before taking the per-AG lock as the per-AG lock can be taken under the i_lock which can be taken from reclaim context. Reported by the new reclaim context tracing in lockdep. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Felix Blyakher <felixb@sgi.com> Signed-off-by: Felix Blyakher <felixb@sgi.com>
-rw-r--r--fs/xfs/xfs_fsops.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index cbd451bb484..2d0b3e1da9e 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -167,17 +167,25 @@ xfs_growfs_data_private(
new = nb - mp->m_sb.sb_dblocks;
oagcount = mp->m_sb.sb_agcount;
if (nagcount > oagcount) {
+ void *new_perag, *old_perag;
+
xfs_filestream_flush(mp);
+
+ new_perag = kmem_zalloc(sizeof(xfs_perag_t) * nagcount,
+ KM_MAYFAIL);
+ if (!new_perag)
+ return XFS_ERROR(ENOMEM);
+
down_write(&mp->m_peraglock);
- mp->m_perag = kmem_realloc(mp->m_perag,
- sizeof(xfs_perag_t) * nagcount,
- sizeof(xfs_perag_t) * oagcount,
- KM_SLEEP);
- memset(&mp->m_perag[oagcount], 0,
- (nagcount - oagcount) * sizeof(xfs_perag_t));
+ memcpy(new_perag, mp->m_perag, sizeof(xfs_perag_t) * oagcount);
+ old_perag = mp->m_perag;
+ mp->m_perag = new_perag;
+
mp->m_flags |= XFS_MOUNT_32BITINODES;
nagimax = xfs_initialize_perag(mp, nagcount);
up_write(&mp->m_peraglock);
+
+ kmem_free(old_perag);
}
tp = xfs_trans_alloc(mp, XFS_TRANS_GROWFS);
tp->t_flags |= XFS_TRANS_RESERVE;