[XFS] sort out opening and closing of the block devices

Currently closing the rt/log block device is done in the wrong spot, and
far too early. So revampt it:

- xfs_blkdev_put moved out of xfs_free_buftarg into the caller so that

it is done after tearing down the buftarg completely.

- call to xfs_unmountfs_close moved from xfs_mountfs into caller so

that it's done after tearing down the filesystem completely.

- xfs_unmountfs_close is renamed to xfs_close_devices and made static

in xfs_super.c

- opening of the block devices is split into a helper xfs_open_devices

that is symetric in use to xfs_close_devices

- xfs_unmountfs can now lose struct cred

- error handling around device opening sanitized in xfs_fs_fill_super

SGI-PV: 981951
SGI-Modid: xfs-linux-melb:xfs-kern:31193a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

4 files changed, 121 insertions, 81 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index ed03c6d3c9c1..9cc8f0213095 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1427,13 +1427,10 @@ xfs_unregister_buftarg(
 
 void
 xfs_free_buftarg(
-        xfs_buftarg_t           *btp,
-        int                     external)
+        xfs_buftarg_t           *btp)
 {
         xfs_flush_buftarg(btp, 1);
         xfs_blkdev_issue_flush(btp);
-        if (external)
-                xfs_blkdev_put(btp->bt_bdev);
         xfs_free_bufhash(btp);
         iput(btp->bt_mapping->host);
 
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index f948ec7ba9a4..29d1d4adc078 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -429,7 +429,7 @@ static inline void xfs_bdwrite(void *mp, xfs_buf_t *bp)
  *      Handling of buftargs.
  */
 extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *, int);
-extern void xfs_free_buftarg(xfs_buftarg_t *, int);
+extern void xfs_free_buftarg(xfs_buftarg_t *);
 extern void xfs_wait_buftarg(xfs_buftarg_t *);
 extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
 extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 4b6ddf88d44e..055faa06ca22 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -766,6 +766,103 @@ xfs_blkdev_issue_flush(
         blkdev_issue_flush(buftarg->bt_bdev, NULL);
 }
 
+STATIC void
+xfs_close_devices(
+        struct xfs_mount        *mp)
+{
+        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
+                xfs_free_buftarg(mp->m_logdev_targp);
+                xfs_blkdev_put(mp->m_logdev_targp->bt_bdev);
+        }
+        if (mp->m_rtdev_targp) {
+                xfs_free_buftarg(mp->m_rtdev_targp);
+                xfs_blkdev_put(mp->m_rtdev_targp->bt_bdev);
+        }
+        xfs_free_buftarg(mp->m_ddev_targp);
+}
+
+/*
+ * The file system configurations are:
+ *      (1) device (partition) with data and internal log
+ *      (2) logical volume with data and log subvolumes.
+ *      (3) logical volume with data, log, and realtime subvolumes.
+ *
+ * We only have to handle opening the log and realtime volumes here if
+ * they are present.  The data subvolume has already been opened by
+ * get_sb_bdev() and is stored in sb->s_bdev.
+ */
+STATIC int
+xfs_open_devices(
+        struct xfs_mount        *mp,
+        struct xfs_mount_args   *args)
+{
+        struct block_device     *ddev = mp->m_super->s_bdev;
+        struct block_device     *logdev = NULL, *rtdev = NULL;
+        int                     error;
+
+        /*
+         * Open real time and log devices - order is important.
+         */
+        if (args->logname[0]) {
+                error = xfs_blkdev_get(mp, args->logname, &logdev);
+                if (error)
+                        goto out;
+        }
+
+        if (args->rtname[0]) {
+                error = xfs_blkdev_get(mp, args->rtname, &rtdev);
+                if (error)
+                        goto out_close_logdev;
+
+                if (rtdev == ddev || rtdev == logdev) {
+                        cmn_err(CE_WARN,
+        "XFS: Cannot mount filesystem with identical rtdev and ddev/logdev.");
+                        error = EINVAL;
+                        goto out_close_rtdev;
+                }
+        }
+
+        /*
+         * Setup xfs_mount buffer target pointers
+         */
+        error = ENOMEM;
+        mp->m_ddev_targp = xfs_alloc_buftarg(ddev, 0);
+        if (!mp->m_ddev_targp)
+                goto out_close_rtdev;
+
+        if (rtdev) {
+                mp->m_rtdev_targp = xfs_alloc_buftarg(rtdev, 1);
+                if (!mp->m_rtdev_targp)
+                        goto out_free_ddev_targ;
+        }
+
+        if (logdev && logdev != ddev) {
+                mp->m_logdev_targp = xfs_alloc_buftarg(logdev, 1);
+                if (!mp->m_logdev_targp)
+                        goto out_free_rtdev_targ;
+        } else {
+                mp->m_logdev_targp = mp->m_ddev_targp;
+        }
+
+        return 0;
+
+ out_free_rtdev_targ:
+        if (mp->m_rtdev_targp)
+                xfs_free_buftarg(mp->m_rtdev_targp);
+ out_free_ddev_targ:
+        xfs_free_buftarg(mp->m_ddev_targp);
+ out_close_rtdev:
+        if (rtdev)
+                xfs_blkdev_put(rtdev);
+ out_close_logdev:
+        if (logdev && logdev != ddev)
+                xfs_blkdev_put(logdev);
+ out:
+        return error;
+}
+
+
+
 /*
  * XFS AIL push thread support
  */
@@ -1138,7 +1235,8 @@ xfs_fs_put_super(
                                 unmount_event_flags);
         }
 
-        xfs_unmountfs(mp, NULL);
+        xfs_unmountfs(mp);
+        xfs_close_devices(mp);
         xfs_qmops_put(mp);
         xfs_dmops_put(mp);
         kmem_free(mp);
@@ -1585,16 +1683,6 @@ xfs_finish_flags(
         return 0;
 }
 
-/*
- * The file system configurations are:
- *      (1) device (partition) with data and internal log
- *      (2) logical volume with data and log subvolumes.
- *      (3) logical volume with data, log, and realtime subvolumes.
- *
- * We only have to handle opening the log and realtime volumes here if
- * they are present.  The data subvolume has already been opened by
- * get_sb_bdev() and is stored in vfsp->vfs_super->s_bdev.
- */
 STATIC int
 xfs_fs_fill_super(
         struct super_block      *sb,
@@ -1604,8 +1692,6 @@ xfs_fs_fill_super(
         struct inode            *root;
         struct xfs_mount        *mp = NULL;
         struct xfs_mount_args   *args = xfs_args_allocate(sb, silent);
-        struct block_device     *ddev = sb->s_bdev;
-        struct block_device     *logdev = NULL, *rtdev = NULL;
         int                     flags = 0, error;
 
         mp = xfs_mount_init();
@@ -1634,61 +1720,14 @@ xfs_fs_fill_super(
                 goto fail_vfsop;
         error = xfs_qmops_get(mp, args);
         if (error)
-                goto fail_vfsop;
+                goto out_put_dmops;
 
         if (args->flags & XFSMNT_QUIET)
                 flags |= XFS_MFSI_QUIET;
 
-        /*
-         * Open real time and log devices - order is important.
-         */
-        if (args->logname[0]) {
-                error = xfs_blkdev_get(mp, args->logname, &logdev);
-                if (error)
-                        goto fail_vfsop;
-        }
-        if (args->rtname[0]) {
-                error = xfs_blkdev_get(mp, args->rtname, &rtdev);
-                if (error) {
-                        xfs_blkdev_put(logdev);
-                        goto fail_vfsop;
-                }
-
-                if (rtdev == ddev || rtdev == logdev) {
-                        cmn_err(CE_WARN,
-        "XFS: Cannot mount filesystem with identical rtdev and ddev/logdev.");
-                        xfs_blkdev_put(logdev);
-                        xfs_blkdev_put(rtdev);
-                        error = EINVAL;
-                        goto fail_vfsop;
-                }
-        }
-
-        /*
-         * Setup xfs_mount buffer target pointers
-         */
-        error = ENOMEM;
-        mp->m_ddev_targp = xfs_alloc_buftarg(ddev, 0);
-        if (!mp->m_ddev_targp) {
-                xfs_blkdev_put(logdev);
-                xfs_blkdev_put(rtdev);
-                goto fail_vfsop;
-        }
-        if (rtdev) {
-                mp->m_rtdev_targp = xfs_alloc_buftarg(rtdev, 1);
-                if (!mp->m_rtdev_targp) {
-                        xfs_blkdev_put(logdev);
-                        xfs_blkdev_put(rtdev);
-                        goto error0;
-                }
-        }
-        mp->m_logdev_targp = (logdev && logdev != ddev) ?
-                                xfs_alloc_buftarg(logdev, 1) : mp->m_ddev_targp;
-        if (!mp->m_logdev_targp) {
-                xfs_blkdev_put(logdev);
-                xfs_blkdev_put(rtdev);
-                goto error0;
-        }
+        error = xfs_open_devices(mp, args);
+        if (error)
+                goto out_put_qmops;
 
         /*
          * Setup flags based on mount(2) options and then the superblock
@@ -1708,7 +1747,9 @@ xfs_fs_fill_super(
          */
         error = xfs_setsize_buftarg(mp->m_ddev_targp, mp->m_sb.sb_blocksize,
                                     mp->m_sb.sb_sectsize);
-        if (!error && logdev && logdev != ddev) {
+        if (error)
+                goto error2;
+        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
                 unsigned int    log_sector_size = BBSIZE;
 
                 if (xfs_sb_version_hassector(&mp->m_sb))
@@ -1716,13 +1757,16 @@ xfs_fs_fill_super(
                 error = xfs_setsize_buftarg(mp->m_logdev_targp,
                                             mp->m_sb.sb_blocksize,
                                             log_sector_size);
+                if (error)
+                        goto error2;
         }
-        if (!error && rtdev)
+        if (mp->m_rtdev_targp) {
                 error = xfs_setsize_buftarg(mp->m_rtdev_targp,
                                             mp->m_sb.sb_blocksize,
                                             mp->m_sb.sb_sectsize);
-        if (error)
-                goto error2;
+                if (error)
+                        goto error2;
+        }
 
         if (mp->m_flags & XFS_MOUNT_BARRIER)
                 xfs_mountfs_check_barriers(mp);
@@ -1778,13 +1822,14 @@ xfs_fs_fill_super(
                 xfs_freesb(mp);
  error1:
         xfs_binval(mp->m_ddev_targp);
-        if (logdev && logdev != ddev)
+        if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
                 xfs_binval(mp->m_logdev_targp);
-        if (rtdev)
+        if (mp->m_rtdev_targp)
                 xfs_binval(mp->m_rtdev_targp);
- error0:
-        xfs_unmountfs_close(mp, NULL);
+        xfs_close_devices(mp);
+ out_put_qmops:
         xfs_qmops_put(mp);
+ out_put_dmops:
         xfs_dmops_put(mp);
         goto fail_vfsop;
 
@@ -1810,7 +1855,8 @@ xfs_fs_fill_super(
 
         IRELE(mp->m_rootip);
 
-        xfs_unmountfs(mp, NULL);
+        xfs_unmountfs(mp);
+        xfs_close_devices(mp);
         xfs_qmops_put(mp);
         xfs_dmops_put(mp);
         kmem_free(mp);
diff --git a/fs/xfs/linux-2.6/xfs_super.h b/fs/xfs/linux-2.6/xfs_super.h
index 3efb7c6d3303..212bdc7a7897 100644
--- a/fs/xfs/linux-2.6/xfs_super.h
+++ b/fs/xfs/linux-2.6/xfs_super.h
@@ -107,9 +107,6 @@ extern void xfs_initialize_vnode(struct xfs_mount *mp, bhv_vnode_t *vp,
 extern void xfs_flush_inode(struct xfs_inode *);
 extern void xfs_flush_device(struct xfs_inode *);
 
-extern int  xfs_blkdev_get(struct xfs_mount *, const char *,
-                                struct block_device **);
-extern void xfs_blkdev_put(struct block_device *);
 extern void xfs_blkdev_issue_flush(struct xfs_buftarg *);
 
 extern const struct export_operations xfs_export_operations;