xfs: add O_TMPFILE support

Add two functions xfs_create_tmpfile() and xfs_vn_tmpfile()
to support O_TMPFILE file creation.

In contrast to xfs_create(), xfs_create_tmpfile() has a different
log reservation to the regular file creation because there is no
directory modification, and doesn't check if an entry can be added
to the directory, but the reservation quotas is required appropriately,
and finally its inode is added to the unlinked list.

xfs_vn_tmpfile() add one O_TMPFILE method to VFS interface and directly
invoke xfs_create_tmpfile().

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/xfs/xfs_shared.h b/fs/xfs/xfs_shared.h
index 8c5035a13df1..4484e5151395 100644
--- a/fs/xfs/xfs_shared.h
+++ b/fs/xfs/xfs_shared.h
@@ -104,7 +104,8 @@ extern const struct xfs_buf_ops xfs_symlink_buf_ops;
 #define XFS_TRANS_SB_COUNT              41
 #define XFS_TRANS_CHECKPOINT            42
 #define XFS_TRANS_ICREATE               43
-#define XFS_TRANS_TYPE_MAX              43
+#define XFS_TRANS_CREATE_TMPFILE        44
+#define XFS_TRANS_TYPE_MAX              44
 /* new transaction types need to be reflected in xfs_logprint(8) */
 
 #define XFS_TRANS_TYPES \
@@ -112,6 +113,7 @@ extern const struct xfs_buf_ops xfs_symlink_buf_ops;
         { XFS_TRANS_SETATTR_SIZE,       "SETATTR_SIZE" }, \
         { XFS_TRANS_INACTIVE,           "INACTIVE" }, \
         { XFS_TRANS_CREATE,             "CREATE" }, \
+        { XFS_TRANS_CREATE_TMPFILE,     "CREATE_TMPFILE" }, \
         { XFS_TRANS_CREATE_TRUNC,       "CREATE_TRUNC" }, \
         { XFS_TRANS_TRUNCATE_FILE,      "TRUNCATE_FILE" }, \
         { XFS_TRANS_REMOVE,             "REMOVE" }, \