xfs: remove obsolete osyncisosync mount option

Since Linux 2.6.33 the kernel has support for real O_SYNC, which made
the osyncisosync option a no-op.  Warn the users about this and remove
the mount flag for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

3 files changed, 4 insertions, 19 deletions

diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
index 9878f50d6ed6..7bff3e4f35df 100644
--- a/Documentation/filesystems/xfs.txt
+++ b/Documentation/filesystems/xfs.txt
@@ -131,17 +131,6 @@ When mounting an XFS filesystem, the following options are accepted.
         Don't check for double mounted file systems using the file system uuid.
         This is useful to mount LVM snapshot volumes.
 
-  osyncisosync
-        Make O_SYNC writes implement true O_SYNC.  WITHOUT this option,
-        Linux XFS behaves as if an "osyncisdsync" option is used,
-        which will make writes to files opened with the O_SYNC flag set
-        behave as if the O_DSYNC flag had been used instead.
-        This can result in better performance without compromising
-        data safety.
-        However if this option is not in effect, timestamp updates from
-        O_SYNC writes can be lost if the system crashes.
-        If timestamp updates are critical, use the osyncisosync option.
-
   uquota/usrquota/uqnoenforce/quota
         User disk quota accounting enabled, and limits (optionally)
         enforced.  Refer to xfs_quota(8) for further details.
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 8c4f4476e5c2..758df94690ed 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -90,7 +90,6 @@ mempool_t *xfs_ioend_pool;
 #define MNTOPT_BARRIER  "barrier"       /* use writer barriers for log write and
                                          * unwritten extent conversion */
 #define MNTOPT_NOBARRIER "nobarrier"    /* .. disable */
-#define MNTOPT_OSYNCISOSYNC "osyncisosync" /* o_sync is REALLY o_sync */
 #define MNTOPT_64BITINODE   "inode64"   /* inodes can be allocated anywhere */
 #define MNTOPT_IKEEP    "ikeep"         /* do not free empty inode clusters */
 #define MNTOPT_NOIKEEP  "noikeep"       /* free empty inode clusters */
@@ -274,8 +273,6 @@ xfs_parseargs(
                         mp->m_flags &= ~XFS_MOUNT_GRPID;
                 } else if (!strcmp(this_char, MNTOPT_WSYNC)) {
                         mp->m_flags |= XFS_MOUNT_WSYNC;
-                } else if (!strcmp(this_char, MNTOPT_OSYNCISOSYNC)) {
-                        mp->m_flags |= XFS_MOUNT_OSYNCISOSYNC;
                 } else if (!strcmp(this_char, MNTOPT_NORECOVERY)) {
                         mp->m_flags |= XFS_MOUNT_NORECOVERY;
                 } else if (!strcmp(this_char, MNTOPT_NOALIGN)) {
@@ -366,9 +363,11 @@ xfs_parseargs(
                         cmn_err(CE_WARN,
         "XFS: ihashsize no longer used, option is deprecated.");
                 } else if (!strcmp(this_char, "osyncisdsync")) {
-                        /* no-op, this is now the default */
                         cmn_err(CE_WARN,
-        "XFS: osyncisdsync is now the default, option is deprecated.");
+        "XFS: osyncisdsync has no effect, option is deprecated.");
+                } else if (!strcmp(this_char, "osyncisosync")) {
+                        cmn_err(CE_WARN,
+        "XFS: osyncisosync has no effect, option is deprecated.");
                 } else if (!strcmp(this_char, "irixsgid")) {
                         cmn_err(CE_WARN,
         "XFS: irixsgid is now a sysctl(2) variable, option is deprecated.");
@@ -500,7 +499,6 @@ xfs_showargs(
                 { XFS_MOUNT_SWALLOC,            "," MNTOPT_SWALLOC },
                 { XFS_MOUNT_NOUUID,             "," MNTOPT_NOUUID },
                 { XFS_MOUNT_NORECOVERY,         "," MNTOPT_NORECOVERY },
-                { XFS_MOUNT_OSYNCISOSYNC,       "," MNTOPT_OSYNCISOSYNC },
                 { XFS_MOUNT_ATTR2,              "," MNTOPT_ATTR2 },
                 { XFS_MOUNT_FILESTREAMS,        "," MNTOPT_FILESTREAM },
                 { XFS_MOUNT_GRPID,              "," MNTOPT_GRPID },
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index e70dc39394ae..622da2179a57 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -220,8 +220,6 @@ typedef struct xfs_mount {
 #define XFS_MOUNT_GRPID         (1ULL << 9)     /* group-ID assigned from directory */
 #define XFS_MOUNT_NORECOVERY    (1ULL << 10)    /* no recovery - dirty fs */
 #define XFS_MOUNT_DFLT_IOSIZE   (1ULL << 12)    /* set default i/o size */
-#define XFS_MOUNT_OSYNCISOSYNC  (1ULL << 13)    /* o_sync is REALLY o_sync */
-                                                /* osyncisdsync is now default*/
 #define XFS_MOUNT_32BITINODES   (1ULL << 14)    /* do not create inodes above
                                                  * 32 bits in size */
 #define XFS_MOUNT_SMALL_INUMS   (1ULL << 15)    /* users wants 32bit inodes */