xfs: factor out xfs_ioctl_setattr transaciton preamble

The setup of the transaction is done after a random smattering of
checks and before another bunch of ioperations specific
validity checks. Pull all the preamble out into a helper function
that returns a transaction or error.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 55 insertions, 46 deletions

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index b0064bdb7a6e..0f62f5b3e221 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1042,7 +1042,6 @@ xfs_ioctl_setattr_xflags(
             !capable(CAP_LINUX_IMMUTABLE))
                 return -EPERM;
 
-        xfs_trans_ijoin(tp, ip, 0);
         xfs_set_diflags(ip, fa->fsx_xflags);
         xfs_diflags_to_linux(ip);
         xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
@@ -1051,6 +1050,54 @@ xfs_ioctl_setattr_xflags(
         return 0;
 }
 
+/*
+ * Set up the transaction structure for the setattr operation, checking that we
+ * have permission to do so. On success, return a clean transaction and the
+ * inode locked exclusively ready for further operation specific checks. On
+ * failure, return an error without modifying or locking the inode.
+ */
+static struct xfs_trans *
+xfs_ioctl_setattr_get_trans(
+        struct xfs_inode        *ip)
+{
+        struct xfs_mount        *mp = ip->i_mount;
+        struct xfs_trans        *tp;
+        int                     error;
+
+        if (mp->m_flags & XFS_MOUNT_RDONLY)
+                return ERR_PTR(-EROFS);
+        if (XFS_FORCED_SHUTDOWN(mp))
+                return ERR_PTR(-EIO);
+
+        tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
+        error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
+        if (error)
+                goto out_cancel;
+
+        xfs_ilock(ip, XFS_ILOCK_EXCL);
+        xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+        /*
+         * CAP_FOWNER overrides the following restrictions:
+         *
+         * The user ID of the calling process must be equal to the file owner
+         * ID, except in cases where the CAP_FSETID capability is applicable.
+         */
+        if (!inode_owner_or_capable(VFS_I(ip))) {
+                error = -EPERM;
+                goto out_cancel;
+        }
+
+        if (mp->m_flags & XFS_MOUNT_WSYNC)
+                xfs_trans_set_sync(tp);
+
+        return tp;
+
+out_cancel:
+        xfs_trans_cancel(tp, 0);
+        return ERR_PTR(error);
+}
+
 #define FSX_PROJID      1
 #define FSX_EXTSIZE     2
 #define FSX_XFLAGS      4
@@ -1063,7 +1110,6 @@ xfs_ioctl_setattr(
 {
         struct xfs_mount        *mp = ip->i_mount;
         struct xfs_trans        *tp;
-        unsigned int            lock_flags = 0;
         struct xfs_dquot        *udqp = NULL;
         struct xfs_dquot        *pdqp = NULL;
         struct xfs_dquot        *olddquot = NULL;
@@ -1071,11 +1117,6 @@ xfs_ioctl_setattr(
 
         trace_xfs_ioctl_setattr(ip);
 
-        if (mp->m_flags & XFS_MOUNT_RDONLY)
-                return -EROFS;
-        if (XFS_FORCED_SHUTDOWN(mp))
-                return -EIO;
-
         /*
          * Disallow 32bit project ids when projid32bit feature is not enabled.
          */
@@ -1099,28 +1140,10 @@ xfs_ioctl_setattr(
                         return code;
         }
 
-        /*
-         * For the other attributes, we acquire the inode lock and
-         * first do an error checking pass.
-         */
-        tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
-        code = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
-        if (code)
-                goto error_return;
-
-        lock_flags = XFS_ILOCK_EXCL;
-        xfs_ilock(ip, lock_flags);
-
-        /*
-         * CAP_FOWNER overrides the following restrictions:
-         *
-         * The user ID of the calling process must be equal
-         * to the file owner ID, except in cases where the
-         * CAP_FSETID capability is applicable.
-         */
-        if (!inode_owner_or_capable(VFS_I(ip))) {
-                code = -EPERM;
-                goto error_return;
+        tp = xfs_ioctl_setattr_get_trans(ip);
+        if (IS_ERR(tp)) {
+                code = PTR_ERR(tp);
+                goto error_free_dquots;
         }
 
         /*
@@ -1244,20 +1267,7 @@ xfs_ioctl_setattr(
                 ip->i_d.di_extsize = extsize;
         }
 
-        /*
-         * If this is a synchronous mount, make sure that the
-         * transaction goes to disk before returning to the user.
-         * This is slightly sub-optimal in that truncates require
-         * two sync transactions instead of one for wsync filesystems.
-         * One for the truncate and one for the timestamps since we
-         * don't want to change the timestamps unless we're sure the
-         * truncate worked.  Truncates are less than 1% of the laddis
-         * mix so this probably isn't worth the trouble to optimize.
-         */
-        if (mp->m_flags & XFS_MOUNT_WSYNC)
-                xfs_trans_set_sync(tp);
         code = xfs_trans_commit(tp, 0);
-        xfs_iunlock(ip, lock_flags);
 
         /*
          * Release any dquot(s) the inode had kept before chown.
@@ -1268,12 +1278,11 @@ xfs_ioctl_setattr(
 
         return code;
 
- error_return:
+error_return:
+        xfs_trans_cancel(tp, 0);
+error_free_dquots:
         xfs_qm_dqrele(udqp);
         xfs_qm_dqrele(pdqp);
-        xfs_trans_cancel(tp, 0);
-        if (lock_flags)
-                xfs_iunlock(ip, lock_flags);
         return code;
 }