xfs: refactor swapext code
authorDarrick J. Wong <darrick.wong@oracle.com>
Mon, 3 Oct 2016 16:11:53 +0000 (09:11 -0700)
committerDarrick J. Wong <darrick.wong@oracle.com>
Wed, 5 Oct 2016 23:26:32 +0000 (16:26 -0700)
Refactor the swapext function to pull out the fork swapping piece
into a separate function.  In the next patch we'll add in the bit
we need to make it work with rmap filesystems.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
fs/xfs/xfs_bmap_util.c

index 9481e5fc247a45e64b93c5f50ef9f31538e06a2b..b278d62b7152f9dafebf96253f9209ef508e754b 100644 (file)
@@ -1649,127 +1649,37 @@ xfs_swap_extent_flush(
        return 0;
 }
 
-int
-xfs_swap_extents(
-       struct xfs_inode        *ip,    /* target inode */
-       struct xfs_inode        *tip,   /* tmp inode */
-       struct xfs_swapext      *sxp)
+/* Swap the extents of two files by swapping data forks. */
+STATIC int
+xfs_swap_extent_forks(
+       struct xfs_trans        *tp,
+       struct xfs_inode        *ip,
+       struct xfs_inode        *tip,
+       int                     *src_log_flags,
+       int                     *target_log_flags)
 {
-       struct xfs_mount        *mp = ip->i_mount;
-       struct xfs_trans        *tp;
-       struct xfs_bstat        *sbp = &sxp->sx_stat;
-       struct xfs_ifork        *tempifp, *ifp, *tifp;
-       int                     src_log_flags, target_log_flags;
-       int                     error = 0;
+       struct xfs_ifork        tempifp, *ifp, *tifp;
        int                     aforkblks = 0;
        int                     taforkblks = 0;
        __uint64_t              tmp;
-       int                     lock_flags;
-       struct xfs_ifork        *cowfp;
-       __uint64_t              f;
-
-       /* XXX: we can't do this with rmap, will fix later */
-       if (xfs_sb_version_hasrmapbt(&mp->m_sb))
-               return -EOPNOTSUPP;
-
-       tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
-       if (!tempifp) {
-               error = -ENOMEM;
-               goto out;
-       }
-
-       /*
-        * Lock the inodes against other IO, page faults and truncate to
-        * begin with.  Then we can ensure the inodes are flushed and have no
-        * page cache safely. Once we have done this we can take the ilocks and
-        * do the rest of the checks.
-        */
-       lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
-       xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
-       xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);
-
-       /* Verify that both files have the same format */
-       if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
-               error = -EINVAL;
-               goto out_unlock;
-       }
-
-       /* Verify both files are either real-time or non-realtime */
-       if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
-               error = -EINVAL;
-               goto out_unlock;
-       }
-
-       error = xfs_swap_extent_flush(ip);
-       if (error)
-               goto out_unlock;
-       error = xfs_swap_extent_flush(tip);
-       if (error)
-               goto out_unlock;
-
-       error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
-       if (error)
-               goto out_unlock;
-
-       /*
-        * Lock and join the inodes to the tansaction so that transaction commit
-        * or cancel will unlock the inodes from this point onwards.
-        */
-       xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
-       lock_flags |= XFS_ILOCK_EXCL;
-       xfs_trans_ijoin(tp, ip, lock_flags);
-       xfs_trans_ijoin(tp, tip, lock_flags);
-
-
-       /* Verify all data are being swapped */
-       if (sxp->sx_offset != 0 ||
-           sxp->sx_length != ip->i_d.di_size ||
-           sxp->sx_length != tip->i_d.di_size) {
-               error = -EFAULT;
-               goto out_trans_cancel;
-       }
-
-       trace_xfs_swap_extent_before(ip, 0);
-       trace_xfs_swap_extent_before(tip, 1);
-
-       /* check inode formats now that data is flushed */
-       error = xfs_swap_extents_check_format(ip, tip);
-       if (error) {
-               xfs_notice(mp,
-                   "%s: inode 0x%llx format is incompatible for exchanging.",
-                               __func__, ip->i_ino);
-               goto out_trans_cancel;
-       }
+       int                     error;
 
-       /*
-        * Compare the current change & modify times with that
-        * passed in.  If they differ, we abort this swap.
-        * This is the mechanism used to ensure the calling
-        * process that the file was not changed out from
-        * under it.
-        */
-       if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
-           (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
-           (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
-           (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
-               error = -EBUSY;
-               goto out_trans_cancel;
-       }
        /*
         * Count the number of extended attribute blocks
         */
        if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
             (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
-               error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
+               error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK,
+                               &aforkblks);
                if (error)
-                       goto out_trans_cancel;
+                       return error;
        }
        if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
             (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
                error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
-                       &taforkblks);
+                               &taforkblks);
                if (error)
-                       goto out_trans_cancel;
+                       return error;
        }
 
        /*
@@ -1778,31 +1688,23 @@ xfs_swap_extents(
         * buffers, and so the validation done on read will expect the owner
         * field to be correctly set. Once we change the owners, we can swap the
         * inode forks.
-        *
-        * Note the trickiness in setting the log flags - we set the owner log
-        * flag on the opposite inode (i.e. the inode we are setting the new
-        * owner to be) because once we swap the forks and log that, log
-        * recovery is going to see the fork as owned by the swapped inode,
-        * not the pre-swapped inodes.
         */
-       src_log_flags = XFS_ILOG_CORE;
-       target_log_flags = XFS_ILOG_CORE;
        if (ip->i_d.di_version == 3 &&
            ip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
-               target_log_flags |= XFS_ILOG_DOWNER;
+               (*target_log_flags) |= XFS_ILOG_DOWNER;
                error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK,
                                              tip->i_ino, NULL);
                if (error)
-                       goto out_trans_cancel;
+                       return error;
        }
 
        if (tip->i_d.di_version == 3 &&
            tip->i_d.di_format == XFS_DINODE_FMT_BTREE) {
-               src_log_flags |= XFS_ILOG_DOWNER;
+               (*src_log_flags) |= XFS_ILOG_DOWNER;
                error = xfs_bmbt_change_owner(tp, tip, XFS_DATA_FORK,
                                              ip->i_ino, NULL);
                if (error)
-                       goto out_trans_cancel;
+                       return error;
        }
 
        /*
@@ -1810,9 +1712,9 @@ xfs_swap_extents(
         */
        ifp = &ip->i_df;
        tifp = &tip->i_df;
-       *tempifp = *ifp;        /* struct copy */
+       tempifp = *ifp;         /* struct copy */
        *ifp = *tifp;           /* struct copy */
-       *tifp = *tempifp;       /* struct copy */
+       *tifp = tempifp;        /* struct copy */
 
        /*
         * Fix the on-disk inode values
@@ -1852,12 +1754,12 @@ xfs_swap_extents(
                        ifp->if_u1.if_extents =
                                ifp->if_u2.if_inline_ext;
                }
-               src_log_flags |= XFS_ILOG_DEXT;
+               (*src_log_flags) |= XFS_ILOG_DEXT;
                break;
        case XFS_DINODE_FMT_BTREE:
                ASSERT(ip->i_d.di_version < 3 ||
-                      (src_log_flags & XFS_ILOG_DOWNER));
-               src_log_flags |= XFS_ILOG_DBROOT;
+                      (*src_log_flags & XFS_ILOG_DOWNER));
+               (*src_log_flags) |= XFS_ILOG_DBROOT;
                break;
        }
 
@@ -1871,15 +1773,126 @@ xfs_swap_extents(
                        tifp->if_u1.if_extents =
                                tifp->if_u2.if_inline_ext;
                }
-               target_log_flags |= XFS_ILOG_DEXT;
+               (*target_log_flags) |= XFS_ILOG_DEXT;
                break;
        case XFS_DINODE_FMT_BTREE:
-               target_log_flags |= XFS_ILOG_DBROOT;
+               (*target_log_flags) |= XFS_ILOG_DBROOT;
                ASSERT(tip->i_d.di_version < 3 ||
-                      (target_log_flags & XFS_ILOG_DOWNER));
+                      (*target_log_flags & XFS_ILOG_DOWNER));
                break;
        }
 
+       return 0;
+}
+
+int
+xfs_swap_extents(
+       struct xfs_inode        *ip,    /* target inode */
+       struct xfs_inode        *tip,   /* tmp inode */
+       struct xfs_swapext      *sxp)
+{
+       struct xfs_mount        *mp = ip->i_mount;
+       struct xfs_trans        *tp;
+       struct xfs_bstat        *sbp = &sxp->sx_stat;
+       int                     src_log_flags, target_log_flags;
+       int                     error = 0;
+       int                     lock_flags;
+       struct xfs_ifork        *cowfp;
+       __uint64_t              f;
+
+       /*
+        * Lock the inodes against other IO, page faults and truncate to
+        * begin with.  Then we can ensure the inodes are flushed and have no
+        * page cache safely. Once we have done this we can take the ilocks and
+        * do the rest of the checks.
+        */
+       lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+       xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
+       xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);
+
+       /* Verify that both files have the same format */
+       if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
+               error = -EINVAL;
+               goto out_unlock;
+       }
+
+       /* Verify both files are either real-time or non-realtime */
+       if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
+               error = -EINVAL;
+               goto out_unlock;
+       }
+
+       error = xfs_swap_extent_flush(ip);
+       if (error)
+               goto out_unlock;
+       error = xfs_swap_extent_flush(tip);
+       if (error)
+               goto out_unlock;
+
+       error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
+       if (error)
+               goto out_unlock;
+
+       /*
+        * Lock and join the inodes to the tansaction so that transaction commit
+        * or cancel will unlock the inodes from this point onwards.
+        */
+       xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
+       lock_flags |= XFS_ILOCK_EXCL;
+       xfs_trans_ijoin(tp, ip, 0);
+       xfs_trans_ijoin(tp, tip, 0);
+
+
+       /* Verify all data are being swapped */
+       if (sxp->sx_offset != 0 ||
+           sxp->sx_length != ip->i_d.di_size ||
+           sxp->sx_length != tip->i_d.di_size) {
+               error = -EFAULT;
+               goto out_trans_cancel;
+       }
+
+       trace_xfs_swap_extent_before(ip, 0);
+       trace_xfs_swap_extent_before(tip, 1);
+
+       /* check inode formats now that data is flushed */
+       error = xfs_swap_extents_check_format(ip, tip);
+       if (error) {
+               xfs_notice(mp,
+                   "%s: inode 0x%llx format is incompatible for exchanging.",
+                               __func__, ip->i_ino);
+               goto out_trans_cancel;
+       }
+
+       /*
+        * Compare the current change & modify times with that
+        * passed in.  If they differ, we abort this swap.
+        * This is the mechanism used to ensure the calling
+        * process that the file was not changed out from
+        * under it.
+        */
+       if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
+           (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
+           (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
+           (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
+               error = -EBUSY;
+               goto out_trans_cancel;
+       }
+
+       /*
+        * Note the trickiness in setting the log flags - we set the owner log
+        * flag on the opposite inode (i.e. the inode we are setting the new
+        * owner to be) because once we swap the forks and log that, log
+        * recovery is going to see the fork as owned by the swapped inode,
+        * not the pre-swapped inodes.
+        */
+       src_log_flags = XFS_ILOG_CORE;
+       target_log_flags = XFS_ILOG_CORE;
+
+       error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,
+                       &target_log_flags);
+       if (error)
+               goto out_trans_cancel;
+
        /* Do we have to swap reflink flags? */
        if ((ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK) ^
            (tip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK)) {
@@ -1909,16 +1922,16 @@ xfs_swap_extents(
 
        trace_xfs_swap_extent_after(ip, 0);
        trace_xfs_swap_extent_after(tip, 1);
-out:
-       kmem_free(tempifp);
-       return error;
 
-out_unlock:
        xfs_iunlock(ip, lock_flags);
        xfs_iunlock(tip, lock_flags);
-       goto out;
+       return error;
 
 out_trans_cancel:
        xfs_trans_cancel(tp);
-       goto out;
+
+out_unlock:
+       xfs_iunlock(ip, lock_flags);
+       xfs_iunlock(tip, lock_flags);
+       return error;
 }