3 files changed, 127 insertions, 26 deletions

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 52fb6c048981..e5ee06231ae5 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1114,7 +1114,7 @@ void gfs2_online_uevent(struct gfs2_sbd *sdp)
  * Returns: errno
  */
 
-static int fill_super(struct super_block *sb, void *data, int silent)
+static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
 {
         struct gfs2_sbd *sdp;
         struct gfs2_holder mount_gh;
@@ -1125,17 +1125,7 @@ static int fill_super(struct super_block *sb, void *data, int silent)
                 printk(KERN_WARNING "GFS2: can't alloc struct gfs2_sbd\n");
                 return -ENOMEM;
         }
-
-        sdp->sd_args.ar_quota = GFS2_QUOTA_DEFAULT;
-        sdp->sd_args.ar_data = GFS2_DATA_DEFAULT;
-        sdp->sd_args.ar_commit = 60;
-        sdp->sd_args.ar_errors = GFS2_ERRORS_DEFAULT;
-
-        error = gfs2_mount_args(sdp, &sdp->sd_args, data);
-        if (error) {
-                printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
-                goto fail;
-        }
+        sdp->sd_args = *args;
 
         if (sdp->sd_args.ar_spectator) {
                 sb->s_flags |= MS_RDONLY;
@@ -1243,18 +1233,125 @@ fail:
         return error;
 }
 
-static int gfs2_get_sb(struct file_system_type *fs_type, int flags,
-                       const char *dev_name, void *data, struct vfsmount *mnt)
+static int set_gfs2_super(struct super_block *s, void *data)
 {
-        return get_sb_bdev(fs_type, flags, dev_name, data, fill_super, mnt);
+        s->s_bdev = data;
+        s->s_dev = s->s_bdev->bd_dev;
+
+        /*
+         * We set the bdi here to the queue backing, file systems can
+         * overwrite this in ->fill_super()
+         */
+        s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
+        return 0;
 }
 
-static int test_meta_super(struct super_block *s, void *ptr)
+static int test_gfs2_super(struct super_block *s, void *ptr)
 {
         struct block_device *bdev = ptr;
         return (bdev == s->s_bdev);
 }
 
+/**
+ * gfs2_get_sb - Get the GFS2 superblock
+ * @fs_type: The GFS2 filesystem type
+ * @flags: Mount flags
+ * @dev_name: The name of the device
+ * @data: The mount arguments
+ * @mnt: The vfsmnt for this mount
+ *
+ * Q. Why not use get_sb_bdev() ?
+ * A. We need to select one of two root directories to mount, independent
+ *    of whether this is the initial, or subsequent, mount of this sb
+ *
+ * Returns: 0 or -ve on error
+ */
+
+static int gfs2_get_sb(struct file_system_type *fs_type, int flags,
+                       const char *dev_name, void *data, struct vfsmount *mnt)
+{
+        struct block_device *bdev;
+        struct super_block *s;
+        fmode_t mode = FMODE_READ;
+        int error;
+        struct gfs2_args args;
+        struct gfs2_sbd *sdp;
+
+        if (!(flags & MS_RDONLY))
+                mode |= FMODE_WRITE;
+
+        bdev = open_bdev_exclusive(dev_name, mode, fs_type);
+        if (IS_ERR(bdev))
+                return PTR_ERR(bdev);
+
+        /*
+         * once the super is inserted into the list by sget, s_umount
+         * will protect the lockfs code from trying to start a snapshot
+         * while we are mounting
+         */
+        mutex_lock(&bdev->bd_fsfreeze_mutex);
+        if (bdev->bd_fsfreeze_count > 0) {
+                mutex_unlock(&bdev->bd_fsfreeze_mutex);
+                error = -EBUSY;
+                goto error_bdev;
+        }
+        s = sget(fs_type, test_gfs2_super, set_gfs2_super, bdev);
+        mutex_unlock(&bdev->bd_fsfreeze_mutex);
+        error = PTR_ERR(s);
+        if (IS_ERR(s))
+                goto error_bdev;
+
+        memset(&args, 0, sizeof(args));
+        args.ar_quota = GFS2_QUOTA_DEFAULT;
+        args.ar_data = GFS2_DATA_DEFAULT;
+        args.ar_commit = 60;
+        args.ar_errors = GFS2_ERRORS_DEFAULT;
+
+        error = gfs2_mount_args(&args, data);
+        if (error) {
+                printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
+                if (s->s_root)
+                        goto error_super;
+                deactivate_locked_super(s);
+                return error;
+        }
+
+        if (s->s_root) {
+                error = -EBUSY;
+                if ((flags ^ s->s_flags) & MS_RDONLY)
+                        goto error_super;
+                close_bdev_exclusive(bdev, mode);
+        } else {
+                char b[BDEVNAME_SIZE];
+
+                s->s_flags = flags;
+                s->s_mode = mode;
+                strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
+                sb_set_blocksize(s, block_size(bdev));
+                error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
+                if (error) {
+                        deactivate_locked_super(s);
+                        return error;
+                }
+                s->s_flags |= MS_ACTIVE;
+                bdev->bd_super = s;
+        }
+
+        sdp = s->s_fs_info;
+        mnt->mnt_sb = s;
+        if (args.ar_meta)
+                mnt->mnt_root = dget(sdp->sd_master_dir);
+        else
+                mnt->mnt_root = dget(sdp->sd_root_dir);
+        return 0;
+
+error_super:
+        deactivate_locked_super(s);
+error_bdev:
+        close_bdev_exclusive(bdev, mode);
+        return error;
+}
+
 static int set_meta_super(struct super_block *s, void *ptr)
 {
         return -EINVAL;
@@ -1274,13 +1371,17 @@ static int gfs2_get_sb_meta(struct file_system_type *fs_type, int flags,
                        dev_name, error);
                 return error;
         }
-        s = sget(&gfs2_fs_type, test_meta_super, set_meta_super,
+        s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super,
                  path.dentry->d_inode->i_sb->s_bdev);
         path_put(&path);
         if (IS_ERR(s)) {
                 printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
                 return PTR_ERR(s);
         }
+        if ((flags ^ s->s_flags) & MS_RDONLY) {
+                deactivate_locked_super(s);
+                return -EBUSY;
+        }
         sdp = s->s_fs_info;
         mnt->mnt_sb = s;
         mnt->mnt_root = dget(sdp->sd_master_dir);
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 0ec3ec672de1..42e5458703f0 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -106,13 +106,13 @@ static const match_table_t tokens = {
 
 /**
  * gfs2_mount_args - Parse mount options
- * @sdp:
- * @data:
+ * @args: The structure into which the parsed options will be written
+ * @options: The options to parse
  *
  * Return: errno
  */
 
-int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *options)
+int gfs2_mount_args(struct gfs2_args *args, char *options)
 {
         char *o;
         int token;
@@ -157,7 +157,7 @@ int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *options)
                         break;
                 case Opt_debug:
                         if (args->ar_errors == GFS2_ERRORS_PANIC) {
-                                fs_info(sdp, "-o debug and -o errors=panic "
+                                printk(KERN_WARNING "GFS2: -o debug and -o errors=panic "
                                        "are mutually exclusive.\n");
                                 return -EINVAL;
                         }
@@ -210,7 +210,7 @@ int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *options)
                 case Opt_commit:
                         rv = match_int(&tmp[0], &args->ar_commit);
                         if (rv || args->ar_commit <= 0) {
-                                fs_info(sdp, "commit mount option requires a positive numeric argument\n");
+                                printk(KERN_WARNING "GFS2: commit mount option requires a positive numeric argument\n");
                                 return rv ? rv : -EINVAL;
                         }
                         break;
@@ -219,7 +219,7 @@ int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *options)
                         break;
                 case Opt_err_panic:
                         if (args->ar_debug) {
-                                fs_info(sdp, "-o debug and -o errors=panic "
+                                printk(KERN_WARNING "GFS2: -o debug and -o errors=panic "
                                         "are mutually exclusive.\n");
                                 return -EINVAL;
                         }
@@ -227,7 +227,7 @@ int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *options)
                         break;
                 case Opt_error:
                 default:
-                        fs_info(sdp, "invalid mount option: %s\n", o);
+                        printk(KERN_WARNING "GFS2: invalid mount option: %s\n", o);
                         return -EINVAL;
                 }
         }
@@ -1062,7 +1062,7 @@ static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
         spin_lock(&gt->gt_spin);
         args.ar_commit = gt->gt_log_flush_secs;
         spin_unlock(&gt->gt_spin);
-        error = gfs2_mount_args(sdp, &args, data);
+        error = gfs2_mount_args(&args, data);
         if (error)
                 return error;
 
diff --git a/fs/gfs2/super.h b/fs/gfs2/super.h
index 235db3682885..ed962ea68c3a 100644
--- a/fs/gfs2/super.h
+++ b/fs/gfs2/super.h
@@ -27,7 +27,7 @@ static inline unsigned int gfs2_jindex_size(struct gfs2_sbd *sdp)
 
 extern void gfs2_jindex_free(struct gfs2_sbd *sdp);
 
-extern int gfs2_mount_args(struct gfs2_sbd *sdp, struct gfs2_args *args, char *data);
+extern int gfs2_mount_args(struct gfs2_args *args, char *data);
 
 extern struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid);
 extern int gfs2_jdesc_check(struct gfs2_jdesc *jd);