From d4d77629953eabd3c14f6fa5746f6b28babfc55f Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 13 Nov 2010 11:55:18 +0100 Subject: 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 Cc: Philipp Reisner Cc: Neil Brown Cc: Mike Snitzer Cc: Joern Engel Cc: Chris Mason Cc: Jan Kara Cc: "Theodore Ts'o" Cc: KONISHI Ryusuke Cc: reiserfs-devel@vger.kernel.org Cc: xfs-masters@oss.sgi.com Cc: Alexander Viro --- fs/block_dev.c | 139 +++++++++++++++++++++++++++++-------------- fs/btrfs/volumes.c | 24 ++++---- fs/btrfs/volumes.h | 2 +- fs/ext3/super.c | 2 +- fs/ext4/super.c | 2 +- fs/gfs2/ops_fstype.c | 8 +-- fs/jfs/jfs_logmgr.c | 4 +- fs/logfs/dev_bdev.c | 3 +- fs/nilfs2/super.c | 8 +-- fs/reiserfs/journal.c | 6 +- fs/super.c | 9 +-- fs/xfs/linux-2.6/xfs_super.c | 3 +- 12 files changed, 132 insertions(+), 78 deletions(-) (limited to 'fs') diff --git a/fs/block_dev.c b/fs/block_dev.c index 606a5259f87f..c1c1b8c3fb99 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -854,24 +854,6 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev) { } #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 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) 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 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) } 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 @@ fail: } 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 f1b729d3b883..95324e9f9280 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -489,7 +489,7 @@ again: 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 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices) 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 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, 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 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices, error_brelse: brelse(bh); error_close: - blkdev_put(bdev, flags | FMODE_EXCL); + blkdev_put(bdev, flags); error: continue; } @@ -684,7 +686,8 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, 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 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, 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 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) 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 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) 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 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) 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 2b638b6e4eea..856e75770304 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -49,7 +49,7 @@ struct btrfs_device { 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 23e7513dba9c..123720ba786d 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -347,7 +347,7 @@ static struct block_device *ext3_blkdev_get(dev_t dev, struct super_block *sb) 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 5dd0b3e76fa8..bd63e6927219 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -647,7 +647,7 @@ static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb) 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 c1f0763a022b..bc56ccf98ffd 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -1268,7 +1268,7 @@ static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags, { 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 @@ static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags, 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 @@ static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags, 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 @@ error_super: 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 5a290f22dcc3..278e3fb40b71 100644 --- a/fs/jfs/jfs_logmgr.c +++ b/fs/jfs/jfs_logmgr.c @@ -1120,8 +1120,8 @@ int lmLogOpen(struct super_block *sb) * 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 734b9025858e..723bc5bca09a 100644 --- a/fs/logfs/dev_bdev.c +++ b/fs/logfs/dev_bdev.c @@ -325,7 +325,8 @@ int logfs_get_sb_bdev(struct logfs_super *p, struct file_system_type *type, { 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 756a6798d7c8..0030640e2d72 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -1147,14 +1147,14 @@ nilfs_mount(struct file_system_type *fs_type, int flags, { 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 @@ nilfs_mount(struct file_system_type *fs_type, int flags, } if (!s_new) - blkdev_put(sd.bdev, mode | FMODE_EXCL); + blkdev_put(sd.bdev, mode); return root_dentry; @@ -1242,7 +1242,7 @@ nilfs_mount(struct file_system_type *fs_type, int flags, 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 b488136f5ace..e2fce519c0f2 100644 --- a/fs/reiserfs/journal.c +++ b/fs/reiserfs/journal.c @@ -2585,7 +2585,8 @@ static int journal_init_dev(struct super_block *super, 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 @@ static int journal_init_dev(struct super_block *super, } 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 22374bf0ba87..5d9a4497849a 100644 --- a/fs/super.c +++ b/fs/super.c @@ -766,13 +766,13 @@ struct dentry *mount_bdev(struct file_system_type *fs_type, { 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 @@ struct dentry *mount_bdev(struct file_system_type *fs_type, * 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 @@ struct dentry *mount_bdev(struct file_system_type *fs_type, 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 @@ void kill_block_super(struct super_block *sb) 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 a1a6e5ceea67..9209cd199c47 100644 --- a/fs/xfs/linux-2.6/xfs_super.c +++ b/fs/xfs/linux-2.6/xfs_super.c @@ -609,7 +609,8 @@ xfs_blkdev_get( { 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); -- cgit v1.2.3