diff options
Diffstat (limited to 'fs/block_dev.c')
-rw-r--r-- | fs/block_dev.c | 768 |
1 files changed, 293 insertions, 475 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 771f2352701..333a7bb4cb9 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -433,7 +433,7 @@ static void init_once(void *foo) INIT_LIST_HEAD(&bdev->bd_inodes); INIT_LIST_HEAD(&bdev->bd_list); #ifdef CONFIG_SYSFS - INIT_LIST_HEAD(&bdev->bd_holder_list); + INIT_LIST_HEAD(&bdev->bd_holder_disks); #endif inode_init_once(&ei->vfs_inode); /* Initialize mutex for freeze. */ @@ -473,7 +473,7 @@ static const struct super_operations bdev_sops = { static struct dentry *bd_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - return mount_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576); + return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, 0x62646576); } static struct file_system_type bd_type = { @@ -669,7 +669,7 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, else if (bdev->bd_contains == bdev) return true; /* is a whole device which isn't held */ - else if (whole->bd_holder == bd_claim) + else if (whole->bd_holder == bd_may_claim) return true; /* is a partition of a device that is being partitioned */ else if (whole->bd_holder != NULL) return false; /* is a partition of a held device */ @@ -781,439 +781,142 @@ static struct block_device *bd_start_claiming(struct block_device *bdev, } } -/* releases bdev_lock */ -static void __bd_abort_claiming(struct block_device *whole, void *holder) -{ - BUG_ON(whole->bd_claiming != holder); - whole->bd_claiming = NULL; - wake_up_bit(&whole->bd_claiming, 0); - - spin_unlock(&bdev_lock); - bdput(whole); -} - -/** - * bd_abort_claiming - abort claiming a block device - * @whole: whole block device returned by bd_start_claiming() - * @holder: holder trying to claim @bdev - * - * Abort a claiming block started by bd_start_claiming(). Note that - * @whole is not the block device to be claimed but the whole device - * returned by bd_start_claiming(). - * - * CONTEXT: - * Grabs and releases bdev_lock. - */ -static void bd_abort_claiming(struct block_device *whole, void *holder) -{ - spin_lock(&bdev_lock); - __bd_abort_claiming(whole, holder); /* releases bdev_lock */ -} - -/* increment holders when we have a legitimate claim. requires bdev_lock */ -static void __bd_claim(struct block_device *bdev, struct block_device *whole, - void *holder) -{ - /* note that for a whole device bd_holders - * will be incremented twice, and bd_holder will - * be set to bd_claim before being set to holder - */ - whole->bd_holders++; - whole->bd_holder = bd_claim; - bdev->bd_holders++; - bdev->bd_holder = holder; -} - -/** - * bd_finish_claiming - finish claiming a block device - * @bdev: block device of interest (passed to bd_start_claiming()) - * @whole: whole block device returned by bd_start_claiming() - * @holder: holder trying to claim @bdev - * - * Finish a claiming block started by bd_start_claiming(). - * - * CONTEXT: - * Grabs and releases bdev_lock. - */ -static void bd_finish_claiming(struct block_device *bdev, - struct block_device *whole, void *holder) -{ - spin_lock(&bdev_lock); - BUG_ON(!bd_may_claim(bdev, whole, holder)); - __bd_claim(bdev, whole, holder); - __bd_abort_claiming(whole, holder); /* not actually an abort */ -} +#ifdef CONFIG_SYSFS +struct bd_holder_disk { + struct list_head list; + struct gendisk *disk; + int refcnt; +}; -/** - * bd_claim - claim a block device - * @bdev: block device to claim - * @holder: holder trying to claim @bdev - * - * Try to claim @bdev which must have been opened successfully. - * - * CONTEXT: - * Might sleep. - * - * RETURNS: - * 0 if successful, -EBUSY if @bdev is already claimed. - */ -int bd_claim(struct block_device *bdev, void *holder) +static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, + struct gendisk *disk) { - struct block_device *whole = bdev->bd_contains; - int res; + struct bd_holder_disk *holder; - might_sleep(); - - spin_lock(&bdev_lock); - res = bd_prepare_to_claim(bdev, whole, holder); - if (res == 0) - __bd_claim(bdev, whole, holder); - spin_unlock(&bdev_lock); - - return res; -} -EXPORT_SYMBOL(bd_claim); - -void bd_release(struct block_device *bdev) -{ - spin_lock(&bdev_lock); - if (!--bdev->bd_contains->bd_holders) - bdev->bd_contains->bd_holder = NULL; - if (!--bdev->bd_holders) - bdev->bd_holder = NULL; - spin_unlock(&bdev_lock); + list_for_each_entry(holder, &bdev->bd_holder_disks, list) + if (holder->disk == disk) + return holder; + return NULL; } -EXPORT_SYMBOL(bd_release); - -#ifdef CONFIG_SYSFS -/* - * Functions for bd_claim_by_kobject / bd_release_from_kobject - * - * If a kobject is passed to bd_claim_by_kobject() - * and the kobject has a parent directory, - * following symlinks are created: - * o from the kobject to the claimed bdev - * o from "holders" directory of the bdev to the parent of the kobject - * bd_release_from_kobject() removes these symlinks. - * - * Example: - * If /dev/dm-0 maps to /dev/sda, kobject corresponding to - * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then: - * /sys/block/dm-0/slaves/sda --> /sys/block/sda - * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 - */ - static int add_symlink(struct kobject *from, struct kobject *to) { - if (!from || !to) - return 0; return sysfs_create_link(from, to, kobject_name(to)); } static void del_symlink(struct kobject *from, struct kobject *to) { - if (!from || !to) - return; sysfs_remove_link(from, kobject_name(to)); } -/* - * 'struct bd_holder' contains pointers to kobjects symlinked by - * bd_claim_by_kobject. - * It's connected to bd_holder_list which is protected by bdev->bd_sem. - */ -struct bd_holder { - struct list_head list; /* chain of holders of the bdev */ - int count; /* references from the holder */ - struct kobject *sdir; /* holder object, e.g. "/block/dm-0/slaves" */ - struct kobject *hdev; /* e.g. "/block/dm-0" */ - struct kobject *hdir; /* e.g. "/block/sda/holders" */ - struct kobject *sdev; /* e.g. "/block/sda" */ -}; - -/* - * Get references of related kobjects at once. - * Returns 1 on success. 0 on failure. - * - * Should call bd_holder_release_dirs() after successful use. - */ -static int bd_holder_grab_dirs(struct block_device *bdev, - struct bd_holder *bo) -{ - if (!bdev || !bo) - return 0; - - bo->sdir = kobject_get(bo->sdir); - if (!bo->sdir) - return 0; - - bo->hdev = kobject_get(bo->sdir->parent); - if (!bo->hdev) - goto fail_put_sdir; - - bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj); - if (!bo->sdev) - goto fail_put_hdev; - - bo->hdir = kobject_get(bdev->bd_part->holder_dir); - if (!bo->hdir) - goto fail_put_sdev; - - return 1; - -fail_put_sdev: - kobject_put(bo->sdev); -fail_put_hdev: - kobject_put(bo->hdev); -fail_put_sdir: - kobject_put(bo->sdir); - - return 0; -} - -/* Put references of related kobjects at once. */ -static void bd_holder_release_dirs(struct bd_holder *bo) -{ - kobject_put(bo->hdir); - kobject_put(bo->sdev); - kobject_put(bo->hdev); - kobject_put(bo->sdir); -} - -static struct bd_holder *alloc_bd_holder(struct kobject *kobj) -{ - struct bd_holder *bo; - - bo = kzalloc(sizeof(*bo), GFP_KERNEL); - if (!bo) - return NULL; - - bo->count = 1; - bo->sdir = kobj; - - return bo; -} - -static void free_bd_holder(struct bd_holder *bo) -{ - kfree(bo); -} - /** - * find_bd_holder - find matching struct bd_holder from the block device + * bd_link_disk_holder - create symlinks between holding disk and slave bdev + * @bdev: the claimed slave bdev + * @disk: the holding disk * - * @bdev: struct block device to be searched - * @bo: target struct bd_holder + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. * - * Returns matching entry with @bo in @bdev->bd_holder_list. - * If found, increment the reference count and return the pointer. - * If not found, returns NULL. - */ -static struct bd_holder *find_bd_holder(struct block_device *bdev, - struct bd_holder *bo) -{ - struct bd_holder *tmp; - - list_for_each_entry(tmp, &bdev->bd_holder_list, list) - if (tmp->sdir == bo->sdir) { - tmp->count++; - return tmp; - } - - return NULL; -} - -/** - * add_bd_holder - create sysfs symlinks for bd_claim() relationship + * This functions creates the following sysfs symlinks. + * + * - from "slaves" directory of the holder @disk to the claimed @bdev + * - from "holders" directory of the @bdev to the holder @disk + * + * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is + * passed to bd_link_disk_holder(), then: * - * @bdev: block device to be bd_claimed - * @bo: preallocated and initialized by alloc_bd_holder() + * /sys/block/dm-0/slaves/sda --> /sys/block/sda + * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 * - * Add @bo to @bdev->bd_holder_list, create symlinks. + * The caller must have claimed @bdev before calling this function and + * ensure that both @bdev and @disk are valid during the creation and + * lifetime of these symlinks. * - * Returns 0 if symlinks are created. - * Returns -ve if something fails. + * CONTEXT: + * Might sleep. + * + * RETURNS: + * 0 on success, -errno on failure. */ -static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo) +int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) { - int err; + struct bd_holder_disk *holder; + int ret = 0; - if (!bo) - return -EINVAL; + mutex_lock(&bdev->bd_mutex); - if (!bd_holder_grab_dirs(bdev, bo)) - return -EBUSY; + WARN_ON_ONCE(!bdev->bd_holder); - err = add_symlink(bo->sdir, bo->sdev); - if (err) - return err; + /* FIXME: remove the following once add_disk() handles errors */ + if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) + goto out_unlock; - err = add_symlink(bo->hdir, bo->hdev); - if (err) { - del_symlink(bo->sdir, bo->sdev); - return err; + holder = bd_find_holder_disk(bdev, disk); + if (holder) { + holder->refcnt++; + goto out_unlock; } - list_add_tail(&bo->list, &bdev->bd_holder_list); - return 0; -} - -/** - * del_bd_holder - delete sysfs symlinks for bd_claim() relationship - * - * @bdev: block device to be bd_claimed - * @kobj: holder's kobject - * - * If there is matching entry with @kobj in @bdev->bd_holder_list - * and no other bd_claim() from the same kobject, - * remove the struct bd_holder from the list, delete symlinks for it. - * - * Returns a pointer to the struct bd_holder when it's removed from the list - * and ready to be freed. - * Returns NULL if matching claim isn't found or there is other bd_claim() - * by the same kobject. - */ -static struct bd_holder *del_bd_holder(struct block_device *bdev, - struct kobject *kobj) -{ - struct bd_holder *bo; - - list_for_each_entry(bo, &bdev->bd_holder_list, list) { - if (bo->sdir == kobj) { - bo->count--; - BUG_ON(bo->count < 0); - if (!bo->count) { - list_del(&bo->list); - del_symlink(bo->sdir, bo->sdev); - del_symlink(bo->hdir, bo->hdev); - bd_holder_release_dirs(bo); - return bo; - } - break; - } + holder = kzalloc(sizeof(*holder), GFP_KERNEL); + if (!holder) { + ret = -ENOMEM; + goto out_unlock; } - return NULL; -} - -/** - * bd_claim_by_kobject - bd_claim() with additional kobject signature - * - * @bdev: block device to be claimed - * @holder: holder's signature - * @kobj: holder's kobject - * - * Do bd_claim() and if it succeeds, create sysfs symlinks between - * the bdev and the holder's kobject. - * Use bd_release_from_kobject() when relesing the claimed bdev. - * - * Returns 0 on success. (same as bd_claim()) - * Returns errno on failure. - */ -static int bd_claim_by_kobject(struct block_device *bdev, void *holder, - struct kobject *kobj) -{ - int err; - struct bd_holder *bo, *found; - - if (!kobj) - return -EINVAL; - - bo = alloc_bd_holder(kobj); - if (!bo) - return -ENOMEM; + INIT_LIST_HEAD(&holder->list); + holder->disk = disk; + holder->refcnt = 1; - mutex_lock(&bdev->bd_mutex); + ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); + if (ret) + goto out_free; - err = bd_claim(bdev, holder); - if (err) - goto fail; + ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); + if (ret) + goto out_del; - found = find_bd_holder(bdev, bo); - if (found) - goto fail; + list_add(&holder->list, &bdev->bd_holder_disks); + goto out_unlock; - err = add_bd_holder(bdev, bo); - if (err) - bd_release(bdev); - else - bo = NULL; -fail: +out_del: + del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); +out_free: + kfree(holder); +out_unlock: mutex_unlock(&bdev->bd_mutex); - free_bd_holder(bo); - return err; + return ret; } +EXPORT_SYMBOL_GPL(bd_link_disk_holder); /** - * bd_release_from_kobject - bd_release() with additional kobject signature + * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() + * @bdev: the calimed slave bdev + * @disk: the holding disk * - * @bdev: block device to be released - * @kobj: holder's kobject + * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. * - * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject(). + * CONTEXT: + * Might sleep. */ -static void bd_release_from_kobject(struct block_device *bdev, - struct kobject *kobj) +void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) { - if (!kobj) - return; + struct bd_holder_disk *holder; mutex_lock(&bdev->bd_mutex); - bd_release(bdev); - free_bd_holder(del_bd_holder(bdev, kobj)); - mutex_unlock(&bdev->bd_mutex); -} -/** - * bd_claim_by_disk - wrapper function for bd_claim_by_kobject() - * - * @bdev: block device to be claimed - * @holder: holder's signature - * @disk: holder's gendisk - * - * Call bd_claim_by_kobject() with getting @disk->slave_dir. - */ -int bd_claim_by_disk(struct block_device *bdev, void *holder, - struct gendisk *disk) -{ - return bd_claim_by_kobject(bdev, holder, kobject_get(disk->slave_dir)); -} -EXPORT_SYMBOL_GPL(bd_claim_by_disk); + holder = bd_find_holder_disk(bdev, disk); -/** - * bd_release_from_disk - wrapper function for bd_release_from_kobject() - * - * @bdev: block device to be claimed - * @disk: holder's gendisk - * - * Call bd_release_from_kobject() and put @disk->slave_dir. - */ -void bd_release_from_disk(struct block_device *bdev, struct gendisk *disk) -{ - bd_release_from_kobject(bdev, disk->slave_dir); - kobject_put(disk->slave_dir); -} -EXPORT_SYMBOL_GPL(bd_release_from_disk); -#endif + if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { + del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); + del_symlink(bdev->bd_part->holder_dir, + &disk_to_dev(disk)->kobj); + list_del_init(&holder->list); + kfree(holder); + } -/* - * 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) -{ - struct block_device *bdev = bdget(dev); - int err = -ENOMEM; - if (bdev) - err = blkdev_get(bdev, mode); - return err ? ERR_PTR(err) : bdev; + mutex_unlock(&bdev->bd_mutex); } - -EXPORT_SYMBOL(open_by_devnum); +EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); +#endif /** * flush_disk - invalidates all buffer-cache entries on a disk @@ -1309,10 +1012,11 @@ int check_disk_change(struct block_device *bdev) { struct gendisk *disk = bdev->bd_disk; const struct block_device_operations *bdops = disk->fops; + unsigned int events; - if (!bdops->media_changed) - return 0; - if (!bdops->media_changed(bdev->bd_disk)) + events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | + DISK_EVENT_EJECT_REQUEST); + if (!(events & DISK_EVENT_MEDIA_CHANGE)) return 0; flush_disk(bdev); @@ -1475,17 +1179,171 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) return ret; } -int blkdev_get(struct block_device *bdev, fmode_t mode) +/** + * 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) { - return __blkdev_get(bdev, mode, 0); + struct block_device *whole = NULL; + int res; + + WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); + + if ((mode & FMODE_EXCL) && holder) { + whole = bd_start_claiming(bdev, holder); + if (IS_ERR(whole)) { + bdput(bdev); + return PTR_ERR(whole); + } + } + + res = __blkdev_get(bdev, mode, 0); + + /* __blkdev_get() may alter read only status, check it afterwards */ + if (!res && (mode & FMODE_WRITE) && bdev_read_only(bdev)) { + __blkdev_put(bdev, mode, 0); + res = -EACCES; + } + + if (whole) { + /* finish claiming */ + mutex_lock(&bdev->bd_mutex); + spin_lock(&bdev_lock); + + if (!res) { + BUG_ON(!bd_may_claim(bdev, whole, holder)); + /* + * Note that for a whole device bd_holders + * will be incremented twice, and bd_holder + * will be set to bd_may_claim before being + * set to holder + */ + whole->bd_holders++; + whole->bd_holder = bd_may_claim; + bdev->bd_holders++; + bdev->bd_holder = holder; + } + + /* tell others that we're done */ + BUG_ON(whole->bd_claiming != holder); + whole->bd_claiming = NULL; + wake_up_bit(&whole->bd_claiming, 0); + + spin_unlock(&bdev_lock); + + /* + * Block event polling for write claims. Any write + * holder makes the write_holder state stick until all + * are released. This is good enough and tracking + * individual writeable reference is too fragile given + * the way @mode is used in blkdev_get/put(). + */ + if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) { + bdev->bd_write_holder = true; + disk_block_events(bdev->bd_disk); + } + + mutex_unlock(&bdev->bd_mutex); + bdput(whole); + } + + return res; } 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 *whole = NULL; struct block_device *bdev; - int res; /* * Preserve backwards compatibility and allow large file access @@ -1506,26 +1364,9 @@ static int blkdev_open(struct inode * inode, struct file * filp) if (bdev == NULL) return -ENOMEM; - if (filp->f_mode & FMODE_EXCL) { - whole = bd_start_claiming(bdev, filp); - if (IS_ERR(whole)) { - bdput(bdev); - return PTR_ERR(whole); - } - } - filp->f_mapping = bdev->bd_inode->i_mapping; - res = blkdev_get(bdev, filp->f_mode); - - if (whole) { - if (res == 0) - bd_finish_claiming(bdev, whole, filp); - else - bd_abort_claiming(whole, filp); - } - - return res; + return blkdev_get(bdev, filp->f_mode, filp); } static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) @@ -1539,6 +1380,7 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_part_count--; if (!--bdev->bd_openers) { + WARN_ON_ONCE(bdev->bd_holders); sync_blockdev(bdev); kill_bdev(bdev); } @@ -1569,6 +1411,44 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) int blkdev_put(struct block_device *bdev, fmode_t mode) { + if (mode & FMODE_EXCL) { + bool bdev_free; + + /* + * Release a claim on the device. The holder fields + * are protected with bdev_lock. bd_mutex is to + * synchronize disk_holder unlinking. + */ + mutex_lock(&bdev->bd_mutex); + spin_lock(&bdev_lock); + + WARN_ON_ONCE(--bdev->bd_holders < 0); + WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); + + /* bd_contains might point to self, check in a separate step */ + if ((bdev_free = !bdev->bd_holders)) + bdev->bd_holder = NULL; + if (!bdev->bd_contains->bd_holders) + bdev->bd_contains->bd_holder = NULL; + + spin_unlock(&bdev_lock); + + /* + * If this was the last claim, remove holder link and + * unblock evpoll if it was a write holder. + */ + if (bdev_free) { + if (bdev->bd_write_holder) { + disk_unblock_events(bdev->bd_disk); + bdev->bd_write_holder = false; + } else + disk_check_events(bdev->bd_disk); + } + + mutex_unlock(&bdev->bd_mutex); + } else + disk_check_events(bdev->bd_disk); + return __blkdev_put(bdev, mode, 0); } EXPORT_SYMBOL(blkdev_put); @@ -1576,8 +1456,7 @@ EXPORT_SYMBOL(blkdev_put); static int blkdev_close(struct inode * inode, struct file * filp) { struct block_device *bdev = I_BDEV(filp->f_mapping->host); - if (bdev->bd_holder == filp) - bd_release(bdev); + return blkdev_put(bdev, filp->f_mode); } @@ -1722,67 +1601,6 @@ 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, *whole; - int error; - - bdev = lookup_bdev(path); - if (IS_ERR(bdev)) - return bdev; - - whole = bd_start_claiming(bdev, holder); - if (IS_ERR(whole)) { - bdput(bdev); - return whole; - } - - error = blkdev_get(bdev, mode); - if (error) - goto out_abort_claiming; - - error = -EACCES; - if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) - goto out_blkdev_put; - - bd_finish_claiming(bdev, whole, holder); - return bdev; - -out_blkdev_put: - blkdev_put(bdev, mode); -out_abort_claiming: - bd_abort_claiming(whole, holder); - return ERR_PTR(error); -} - -EXPORT_SYMBOL(open_bdev_exclusive); - -/** - * close_bdev_exclusive - close a blockdevice opened by open_bdev_exclusive() - * - * @bdev: blockdevice to close - * @mode: mode, must match that used to open. - * - * This is the counterpart to open_bdev_exclusive(). - */ -void close_bdev_exclusive(struct block_device *bdev, fmode_t mode) -{ - bd_release(bdev); - blkdev_put(bdev, mode); -} - -EXPORT_SYMBOL(close_bdev_exclusive); - int __invalidate_device(struct block_device *bdev) { struct super_block *sb = get_super(bdev); |