xfs: handle ENOMEM correctly during initialisation of perag structures
Add proper error handling in case an error occurs while initializing
new perag structures for a mount point. The mount structure is
restored to its previous state by deleting and freeing any perag
structures added during the call.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 049dbc7..be643e5 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -432,11 +432,13 @@
xfs_agnumber_t *maxagi)
{
xfs_agnumber_t index, max_metadata;
+ xfs_agnumber_t first_initialised = 0;
xfs_perag_t *pag;
xfs_agino_t agino;
xfs_ino_t ino;
xfs_sb_t *sbp = &mp->m_sb;
xfs_ino_t max_inum = XFS_MAXINUMBER_32;
+ int error = -ENOMEM;
/* Check to see if the filesystem can overflow 32 bit inodes */
agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
@@ -453,17 +455,20 @@
xfs_perag_put(pag);
continue;
}
+ if (!first_initialised)
+ first_initialised = index;
pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
if (!pag)
- return -ENOMEM;
+ goto out_unwind;
if (radix_tree_preload(GFP_NOFS))
- return -ENOMEM;
+ goto out_unwind;
spin_lock(&mp->m_perag_lock);
if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
BUG();
spin_unlock(&mp->m_perag_lock);
- kmem_free(pag);
- return -EEXIST;
+ radix_tree_preload_end();
+ error = -EEXIST;
+ goto out_unwind;
}
pag->pag_agno = index;
pag->pag_mount = mp;
@@ -523,6 +528,14 @@
if (maxagi)
*maxagi = index;
return 0;
+
+out_unwind:
+ kmem_free(pag);
+ for (; index > first_initialised; index--) {
+ pag = radix_tree_delete(&mp->m_perag_tree, index);
+ kmem_free(pag);
+ }
+ return error;
}
void