block: clean up blkdev_get() wrappers and their users
After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().
blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.
All users are converted. Most conversions are mechanical and don't
introduce any behavior difference. There are several exceptions.
* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
reason to OR it explicitly on blkdev_put().
* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
sb->s_mode.
* With the above changes, sb->s_mode now always should contain
FMODE_EXCL. WARN_ON_ONCE() added to kill_block_super() to detect
errors.
The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 606a525..c1c1b8c 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -854,24 +854,6 @@
{ }
#endif
-/*
- * Tries to open block device by device number. Use it ONLY if you
- * really do not have anything better - i.e. when you are behind a
- * truly sucky interface and all you are given is a device number. _Never_
- * to be used for internal purposes. If you ever need it - reconsider
- * your API.
- */
-struct block_device *open_by_devnum(dev_t dev, fmode_t mode, void *holder)
-{
- struct block_device *bdev = bdget(dev);
- int err = -ENOMEM;
- if (bdev)
- err = blkdev_get(bdev, mode, holder);
- return err ? ERR_PTR(err) : bdev;
-}
-
-EXPORT_SYMBOL(open_by_devnum);
-
/**
* flush_disk - invalidates all buffer-cache entries on a disk
*
@@ -1132,6 +1114,25 @@
return ret;
}
+/**
+ * blkdev_get - open a block device
+ * @bdev: block_device to open
+ * @mode: FMODE_* mask
+ * @holder: exclusive holder identifier
+ *
+ * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is
+ * open with exclusive access. Specifying %FMODE_EXCL with %NULL
+ * @holder is invalid. Exclusive opens may nest for the same @holder.
+ *
+ * On success, the reference count of @bdev is unchanged. On failure,
+ * @bdev is put.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
{
struct block_device *whole = NULL;
@@ -1186,6 +1187,80 @@
}
EXPORT_SYMBOL(blkdev_get);
+/**
+ * blkdev_get_by_path - open a block device by name
+ * @path: path to the block device to open
+ * @mode: FMODE_* mask
+ * @holder: exclusive holder identifier
+ *
+ * Open the blockdevice described by the device file at @path. @mode
+ * and @holder are identical to blkdev_get().
+ *
+ * On success, the returned block_device has reference count of one.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * Pointer to block_device on success, ERR_PTR(-errno) on failure.
+ */
+struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
+ void *holder)
+{
+ struct block_device *bdev;
+ int err;
+
+ bdev = lookup_bdev(path);
+ if (IS_ERR(bdev))
+ return bdev;
+
+ err = blkdev_get(bdev, mode, holder);
+ if (err)
+ return ERR_PTR(err);
+
+ return bdev;
+}
+EXPORT_SYMBOL(blkdev_get_by_path);
+
+/**
+ * blkdev_get_by_dev - open a block device by device number
+ * @dev: device number of block device to open
+ * @mode: FMODE_* mask
+ * @holder: exclusive holder identifier
+ *
+ * Open the blockdevice described by device number @dev. @mode and
+ * @holder are identical to blkdev_get().
+ *
+ * Use it ONLY if you really do not have anything better - i.e. when
+ * you are behind a truly sucky interface and all you are given is a
+ * device number. _Never_ to be used for internal purposes. If you
+ * ever need it - reconsider your API.
+ *
+ * On success, the returned block_device has reference count of one.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * Pointer to block_device on success, ERR_PTR(-errno) on failure.
+ */
+struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
+{
+ struct block_device *bdev;
+ int err;
+
+ bdev = bdget(dev);
+ if (!bdev)
+ return ERR_PTR(-ENOMEM);
+
+ err = blkdev_get(bdev, mode, holder);
+ if (err)
+ return ERR_PTR(err);
+
+ return bdev;
+}
+EXPORT_SYMBOL(blkdev_get_by_dev);
+
static int blkdev_open(struct inode * inode, struct file * filp)
{
struct block_device *bdev;
@@ -1436,34 +1511,6 @@
}
EXPORT_SYMBOL(lookup_bdev);
-/**
- * open_bdev_exclusive - open a block device by name and set it up for use
- *
- * @path: special file representing the block device
- * @mode: FMODE_... combination to pass be used
- * @holder: owner for exclusion
- *
- * Open the blockdevice described by the special file at @path, claim it
- * for the @holder.
- */
-struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *holder)
-{
- struct block_device *bdev;
- int error;
-
- bdev = lookup_bdev(path);
- if (IS_ERR(bdev))
- return bdev;
-
- error = blkdev_get(bdev, mode | FMODE_EXCL, holder);
- if (error)
- return ERR_PTR(error);
-
- return bdev;
-}
-
-EXPORT_SYMBOL(open_bdev_exclusive);
-
int __invalidate_device(struct block_device *bdev)
{
struct super_block *sb = get_super(bdev);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f1b729d..95324e9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -489,7 +489,7 @@
continue;
if (device->bdev) {
- blkdev_put(device->bdev, device->mode | FMODE_EXCL);
+ blkdev_put(device->bdev, device->mode);
device->bdev = NULL;
fs_devices->open_devices--;
}
@@ -523,7 +523,7 @@
list_for_each_entry(device, &fs_devices->devices, dev_list) {
if (device->bdev) {
- blkdev_put(device->bdev, device->mode | FMODE_EXCL);
+ blkdev_put(device->bdev, device->mode);
fs_devices->open_devices--;
}
if (device->writeable) {
@@ -580,13 +580,15 @@
int seeding = 1;
int ret = 0;
+ flags |= FMODE_EXCL;
+
list_for_each_entry(device, head, dev_list) {
if (device->bdev)
continue;
if (!device->name)
continue;
- bdev = open_bdev_exclusive(device->name, flags, holder);
+ bdev = blkdev_get_by_path(device->name, flags, holder);
if (IS_ERR(bdev)) {
printk(KERN_INFO "open %s failed\n", device->name);
goto error;
@@ -638,7 +640,7 @@
error_brelse:
brelse(bh);
error_close:
- blkdev_put(bdev, flags | FMODE_EXCL);
+ blkdev_put(bdev, flags);
error:
continue;
}
@@ -684,7 +686,8 @@
mutex_lock(&uuid_mutex);
- bdev = open_bdev_exclusive(path, flags, holder);
+ flags |= FMODE_EXCL;
+ bdev = blkdev_get_by_path(path, flags, holder);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
@@ -716,7 +719,7 @@
brelse(bh);
error_close:
- blkdev_put(bdev, flags | FMODE_EXCL);
+ blkdev_put(bdev, flags);
error:
mutex_unlock(&uuid_mutex);
return ret;
@@ -1179,8 +1182,8 @@
goto out;
}
} else {
- bdev = open_bdev_exclusive(device_path, FMODE_READ,
- root->fs_info->bdev_holder);
+ bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
+ root->fs_info->bdev_holder);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
goto out;
@@ -1244,7 +1247,7 @@
root->fs_info->fs_devices->latest_bdev = next_device->bdev;
if (device->bdev) {
- blkdev_put(device->bdev, device->mode | FMODE_EXCL);
+ blkdev_put(device->bdev, device->mode);
device->bdev = NULL;
device->fs_devices->open_devices--;
}
@@ -1439,7 +1442,8 @@
if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
return -EINVAL;
- bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
+ bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
+ root->fs_info->bdev_holder);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 2b638b6..856e757 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -49,7 +49,7 @@
struct block_device *bdev;
- /* the mode sent to open_bdev_exclusive */
+ /* the mode sent to blkdev_get */
fmode_t mode;
char *name;
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 23e7513..123720b 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -347,7 +347,7 @@
struct block_device *bdev;
char b[BDEVNAME_SIZE];
- bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
+ bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
if (IS_ERR(bdev))
goto fail;
return bdev;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 5dd0b3e..bd63e69 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -647,7 +647,7 @@
struct block_device *bdev;
char b[BDEVNAME_SIZE];
- bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
+ bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
if (IS_ERR(bdev))
goto fail;
return bdev;
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index c1f0763..bc56ccf 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1268,7 +1268,7 @@
{
struct block_device *bdev;
struct super_block *s;
- fmode_t mode = FMODE_READ;
+ fmode_t mode = FMODE_READ | FMODE_EXCL;
int error;
struct gfs2_args args;
struct gfs2_sbd *sdp;
@@ -1276,7 +1276,7 @@
if (!(flags & MS_RDONLY))
mode |= FMODE_WRITE;
- bdev = open_bdev_exclusive(dev_name, mode, fs_type);
+ bdev = blkdev_get_by_path(dev_name, mode, fs_type);
if (IS_ERR(bdev))
return ERR_CAST(bdev);
@@ -1298,7 +1298,7 @@
goto error_bdev;
if (s->s_root)
- blkdev_put(bdev, mode | FMODE_EXCL);
+ blkdev_put(bdev, mode);
memset(&args, 0, sizeof(args));
args.ar_quota = GFS2_QUOTA_DEFAULT;
@@ -1342,7 +1342,7 @@
deactivate_locked_super(s);
return ERR_PTR(error);
error_bdev:
- blkdev_put(bdev, mode | FMODE_EXCL);
+ blkdev_put(bdev, mode);
return ERR_PTR(error);
}
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 5a290f2..278e3fb 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -1120,8 +1120,8 @@
* file systems to log may have n-to-1 relationship;
*/
- bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
- log);
+ bdev = blkdev_get_by_dev(sbi->logdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
+ log);
if (IS_ERR(bdev)) {
rc = -PTR_ERR(bdev);
goto free;
diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index 734b902..723bc5b 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -325,7 +325,8 @@
{
struct block_device *bdev;
- bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, type);
+ bdev = blkdev_get_by_path(devname, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
+ type);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 756a679..0030640 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1147,14 +1147,14 @@
{
struct nilfs_super_data sd;
struct super_block *s;
- fmode_t mode = FMODE_READ;
+ fmode_t mode = FMODE_READ | FMODE_EXCL;
struct dentry *root_dentry;
int err, s_new = false;
if (!(flags & MS_RDONLY))
mode |= FMODE_WRITE;
- sd.bdev = open_bdev_exclusive(dev_name, mode, fs_type);
+ sd.bdev = blkdev_get_by_path(dev_name, mode, fs_type);
if (IS_ERR(sd.bdev))
return ERR_CAST(sd.bdev);
@@ -1233,7 +1233,7 @@
}
if (!s_new)
- blkdev_put(sd.bdev, mode | FMODE_EXCL);
+ blkdev_put(sd.bdev, mode);
return root_dentry;
@@ -1242,7 +1242,7 @@
failed:
if (!s_new)
- blkdev_put(sd.bdev, mode | FMODE_EXCL);
+ blkdev_put(sd.bdev, mode);
return ERR_PTR(err);
}
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index b488136..e2fce519 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -2585,7 +2585,8 @@
if ((!jdev_name || !jdev_name[0])) {
if (jdev == super->s_dev)
blkdev_mode &= ~FMODE_EXCL;
- journal->j_dev_bd = open_by_devnum(jdev, blkdev_mode, journal);
+ journal->j_dev_bd = blkdev_get_by_dev(jdev, blkdev_mode,
+ journal);
journal->j_dev_mode = blkdev_mode;
if (IS_ERR(journal->j_dev_bd)) {
result = PTR_ERR(journal->j_dev_bd);
@@ -2601,8 +2602,7 @@
}
journal->j_dev_mode = blkdev_mode;
- journal->j_dev_bd = open_bdev_exclusive(jdev_name,
- blkdev_mode, journal);
+ journal->j_dev_bd = blkdev_get_by_path(jdev_name, blkdev_mode, journal);
if (IS_ERR(journal->j_dev_bd)) {
result = PTR_ERR(journal->j_dev_bd);
journal->j_dev_bd = NULL;
diff --git a/fs/super.c b/fs/super.c
index 22374bf..5d9a449 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -766,13 +766,13 @@
{
struct block_device *bdev;
struct super_block *s;
- fmode_t mode = FMODE_READ;
+ fmode_t mode = FMODE_READ | FMODE_EXCL;
int error = 0;
if (!(flags & MS_RDONLY))
mode |= FMODE_WRITE;
- bdev = open_bdev_exclusive(dev_name, mode, fs_type);
+ bdev = blkdev_get_by_path(dev_name, mode, fs_type);
if (IS_ERR(bdev))
return ERR_CAST(bdev);
@@ -807,7 +807,7 @@
* holding an active reference.
*/
up_write(&s->s_umount);
- blkdev_put(bdev, mode | FMODE_EXCL);
+ blkdev_put(bdev, mode);
down_write(&s->s_umount);
} else {
char b[BDEVNAME_SIZE];
@@ -831,7 +831,7 @@
error_s:
error = PTR_ERR(s);
error_bdev:
- blkdev_put(bdev, mode | FMODE_EXCL);
+ blkdev_put(bdev, mode);
error:
return ERR_PTR(error);
}
@@ -862,6 +862,7 @@
bdev->bd_super = NULL;
generic_shutdown_super(sb);
sync_blockdev(bdev);
+ WARN_ON_ONCE(!(mode & FMODE_EXCL));
blkdev_put(bdev, mode | FMODE_EXCL);
}
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index a1a6e5c..9209cd1 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -609,7 +609,8 @@
{
int error = 0;
- *bdevp = open_bdev_exclusive(name, FMODE_READ|FMODE_WRITE, mp);
+ *bdevp = blkdev_get_by_path(name, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
+ mp);
if (IS_ERR(*bdevp)) {
error = PTR_ERR(*bdevp);
printk("XFS: Invalid device [%s], error=%d\n", name, error);