[XFS] Make hole punching at EOF atomic.

If hole punching at EOF is done as two steps (i.e. truncate then extend)
the file is in a transient state between the two steps where an
application can see the incorrect file size. Punching a hole to EOF needs
to be treated in teh same way as all other hole punching cases so that the
file size is never seen to change.

SGI-PV: 962012
SGI-Modid: xfs-linux-melb:xfs-kern:28641a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/fs/xfs/xfs_rw.h b/fs/xfs/xfs_rw.h
index 188b296ff50c..ba74000931ec 100644
--- a/fs/xfs/xfs_rw.h
+++ b/fs/xfs/xfs_rw.h
@@ -72,6 +72,12 @@ xfs_fsb_to_db_io(struct xfs_iocore *io, xfs_fsblock_t fsb)
 }
 
 /*
+ * Flags for xfs_free_eofblocks
+ */
+#define XFS_FREE_EOF_LOCK       (1<<0)
+#define XFS_FREE_EOF_NOLOCK     (1<<1)
+
+/*
  * Prototypes for functions in xfs_rw.c.
  */
 extern int xfs_write_clear_setuid(struct xfs_inode *ip);
@@ -91,10 +97,12 @@ extern void xfs_ioerror_alert(char *func, struct xfs_mount *mp,
 extern int xfs_rwlock(bhv_desc_t *bdp, bhv_vrwlock_t write_lock);
 extern void xfs_rwunlock(bhv_desc_t *bdp, bhv_vrwlock_t write_lock);
 extern int xfs_setattr(bhv_desc_t *, bhv_vattr_t *vap, int flags,
-                       cred_t *credp);
+                        cred_t *credp);
 extern int xfs_change_file_space(bhv_desc_t *bdp, int cmd, xfs_flock64_t *bf,
-                                 xfs_off_t offset, cred_t *credp, int flags);
+                        xfs_off_t offset, cred_t *credp, int flags);
 extern int xfs_set_dmattrs(bhv_desc_t *bdp, u_int evmask, u_int16_t state,
-                           cred_t *credp);
+                        cred_t *credp);
+extern int xfs_free_eofblocks(struct xfs_mount *mp, struct xfs_inode *ip,
+                        int flags);
 
 #endif /* __XFS_RW_H__ */