[PATCH] xfs: use inode_init_always_gfp with __GFP_NOFAIL in xfs_inode_alloc

[Christoph Hellwig <hch@lst.de>]

Just like the inode allocation itself, allocation of the security data
inside of inode_init_always(_gfp) must not fail here as we can be inside
an already dirty transaction context.  Note that we do not have to pass
GFP_NOFS explicitly as we are already in a nofs context when in a
transaction, as seen by the call to alloc_inode_sb.

Also update the comment about this a bit to be more clear.

Fixes: bf904248a2ad ("[XFS] Combine the XFS and Linux inodes")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_icache.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 9d8dd30bd927..a857b8aa255c 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -82,24 +82,20 @@ static inline xa_mark_t ici_tag_to_mark(unsigned int tag)
 
 /*
  * Allocate and initialise an xfs_inode.
+ *
+ * This can happen in context of already dirtied transactions, so the memory
+ * allocations must not fail.
  */
 struct xfs_inode *
 xfs_inode_alloc(
 	struct xfs_mount	*mp,
 	xfs_ino_t		ino)
 {
+	gfp_t			gfp = GFP_KERNEL | __GFP_NOFAIL;
 	struct xfs_inode	*ip;
 
-	/*
-	 * XXX: If this didn't occur in transactions, we could drop GFP_NOFAIL
-	 * and return NULL here on ENOMEM.
-	 */
-	ip = alloc_inode_sb(mp->m_super, xfs_inode_cache, GFP_KERNEL | __GFP_NOFAIL);
-
-	if (inode_init_always(mp->m_super, VFS_I(ip))) {
-		kmem_cache_free(xfs_inode_cache, ip);
-		return NULL;
-	}
+	ip = alloc_inode_sb(mp->m_super, xfs_inode_cache, gfp);
+	inode_init_always_gfp(mp->m_super, VFS_I(ip), gfp);
 
 	VFS_I(ip)->i_ino = ino;
 	/* VFS doesn't initialise i_mode! */
-- 
2.53.0