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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-16 12:57:51 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-16 12:57:51 -0800 |
commit | ac7ac4618cf25e0d5cd8eba83d5f600084b65b9a (patch) | |
tree | e5d28907ff72690a0463a2238b96202d751a535c /fs/block_dev.c | |
parent | 48aba79bcf6ea05148dc82ad9c40713960b00396 (diff) | |
parent | fa94ba8a7b22890e6a17b39b9359e114fe18cd59 (diff) | |
download | linux-stable-ac7ac4618cf25e0d5cd8eba83d5f600084b65b9a.tar.gz linux-stable-ac7ac4618cf25e0d5cd8eba83d5f600084b65b9a.tar.bz2 linux-stable-ac7ac4618cf25e0d5cd8eba83d5f600084b65b9a.zip |
Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
"Another series of killing more code than what is being added, again
thanks to Christoph's relentless cleanups and tech debt tackling.
This contains:
- blk-iocost improvements (Baolin Wang)
- part0 iostat fix (Jeffle Xu)
- Disable iopoll for split bios (Jeffle Xu)
- block tracepoint cleanups (Christoph Hellwig)
- Merging of struct block_device and hd_struct (Christoph Hellwig)
- Rework/cleanup of how block device sizes are updated (Christoph
Hellwig)
- Simplification of gendisk lookup and removal of block device
aliasing (Christoph Hellwig)
- Block device ioctl cleanups (Christoph Hellwig)
- Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig)
- Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig)
- sbitmap improvements (Pavel Begunkov)
- Hybrid polling fix (Pavel Begunkov)
- bvec iteration improvements (Pavel Begunkov)
- Zone revalidation fixes (Damien Le Moal)
- blk-throttle limit fix (Yu Kuai)
- Various little fixes"
* tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits)
blk-mq: fix msec comment from micro to milli seconds
blk-mq: update arg in comment of blk_mq_map_queue
blk-mq: add helper allocating tagset->tags
Revert "block: Fix a lockdep complaint triggered by request queue flushing"
nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class
blk-mq: add new API of blk_mq_hctx_set_fq_lock_class
block: disable iopoll for split bio
block: Improve blk_revalidate_disk_zones() checks
sbitmap: simplify wrap check
sbitmap: replace CAS with atomic and
sbitmap: remove swap_lock
sbitmap: optimise sbitmap_deferred_clear()
blk-mq: skip hybrid polling if iopoll doesn't spin
blk-iocost: Factor out the base vrate change into a separate function
blk-iocost: Factor out the active iocgs' state check into a separate function
blk-iocost: Move the usage ratio calculation to the correct place
blk-iocost: Remove unnecessary advance declaration
blk-iocost: Fix some typos in comments
blktrace: fix up a kerneldoc comment
block: remove the request_queue to argument request based tracepoints
...
Diffstat (limited to 'fs/block_dev.c')
-rw-r--r-- | fs/block_dev.c | 755 |
1 files changed, 265 insertions, 490 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 9e84b1928b94..9e56ee1f2652 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -32,6 +32,7 @@ #include <linux/cleancache.h> #include <linux/task_io_accounting_ops.h> #include <linux/falloc.h> +#include <linux/part_stat.h> #include <linux/uaccess.h> #include <linux/suspend.h> #include "internal.h" @@ -110,24 +111,20 @@ EXPORT_SYMBOL(invalidate_bdev); int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart, loff_t lend) { - struct block_device *claimed_bdev = NULL; - int err; - /* * If we don't hold exclusive handle for the device, upgrade to it * while we discard the buffer cache to avoid discarding buffers * under live filesystem. */ if (!(mode & FMODE_EXCL)) { - claimed_bdev = bdev->bd_contains; - err = bd_prepare_to_claim(bdev, claimed_bdev, - truncate_bdev_range); + int err = bd_prepare_to_claim(bdev, truncate_bdev_range); if (err) return err; } + truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); - if (claimed_bdev) - bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range); + if (!(mode & FMODE_EXCL)) + bd_abort_claiming(bdev, truncate_bdev_range); return 0; } EXPORT_SYMBOL(truncate_bdev_range); @@ -548,55 +545,47 @@ EXPORT_SYMBOL(fsync_bdev); * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze * actually. */ -struct super_block *freeze_bdev(struct block_device *bdev) +int freeze_bdev(struct block_device *bdev) { struct super_block *sb; int error = 0; mutex_lock(&bdev->bd_fsfreeze_mutex); - if (++bdev->bd_fsfreeze_count > 1) { - /* - * We don't even need to grab a reference - the first call - * to freeze_bdev grab an active reference and only the last - * thaw_bdev drops it. - */ - sb = get_super(bdev); - if (sb) - drop_super(sb); - mutex_unlock(&bdev->bd_fsfreeze_mutex); - return sb; - } + if (++bdev->bd_fsfreeze_count > 1) + goto done; sb = get_active_super(bdev); if (!sb) - goto out; + goto sync; if (sb->s_op->freeze_super) error = sb->s_op->freeze_super(sb); else error = freeze_super(sb); + deactivate_super(sb); + if (error) { - deactivate_super(sb); bdev->bd_fsfreeze_count--; - mutex_unlock(&bdev->bd_fsfreeze_mutex); - return ERR_PTR(error); + goto done; } - deactivate_super(sb); - out: + bdev->bd_fsfreeze_sb = sb; + +sync: sync_blockdev(bdev); +done: mutex_unlock(&bdev->bd_fsfreeze_mutex); - return sb; /* thaw_bdev releases s->s_umount */ + return error; } EXPORT_SYMBOL(freeze_bdev); /** * thaw_bdev -- unlock filesystem * @bdev: blockdevice to unlock - * @sb: associated superblock * * Unlocks the filesystem and marks it writeable again after freeze_bdev(). */ -int thaw_bdev(struct block_device *bdev, struct super_block *sb) +int thaw_bdev(struct block_device *bdev) { + struct super_block *sb; int error = -EINVAL; mutex_lock(&bdev->bd_fsfreeze_mutex); @@ -607,6 +596,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) if (--bdev->bd_fsfreeze_count > 0) goto out; + sb = bdev->bd_fsfreeze_sb; if (!sb) goto out; @@ -792,23 +782,19 @@ static struct inode *bdev_alloc_inode(struct super_block *sb) static void bdev_free_inode(struct inode *inode) { + struct block_device *bdev = I_BDEV(inode); + + free_percpu(bdev->bd_stats); + kfree(bdev->bd_meta_info); + kmem_cache_free(bdev_cachep, BDEV_I(inode)); } -static void init_once(void *foo) +static void init_once(void *data) { - struct bdev_inode *ei = (struct bdev_inode *) foo; - struct block_device *bdev = &ei->bdev; + struct bdev_inode *ei = data; - memset(bdev, 0, sizeof(*bdev)); - mutex_init(&bdev->bd_mutex); -#ifdef CONFIG_SYSFS - INIT_LIST_HEAD(&bdev->bd_holder_disks); -#endif - bdev->bd_bdi = &noop_backing_dev_info; inode_init_once(&ei->vfs_inode); - /* Initialize mutex for freeze. */ - mutex_init(&bdev->bd_fsfreeze_mutex); } static void bdev_evict_inode(struct inode *inode) @@ -870,72 +856,72 @@ void __init bdev_cache_init(void) blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ } -/* - * Most likely _very_ bad one - but then it's hardly critical for small - * /dev and can be fixed when somebody will need really large one. - * Keep in mind that it will be fed through icache hash function too. - */ -static inline unsigned long hash(dev_t dev) +struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) { - return MAJOR(dev)+MINOR(dev); -} + struct block_device *bdev; + struct inode *inode; -static int bdev_test(struct inode *inode, void *data) -{ - return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; + inode = new_inode(blockdev_superblock); + if (!inode) + return NULL; + inode->i_mode = S_IFBLK; + inode->i_rdev = 0; + inode->i_data.a_ops = &def_blk_aops; + mapping_set_gfp_mask(&inode->i_data, GFP_USER); + + bdev = I_BDEV(inode); + memset(bdev, 0, sizeof(*bdev)); + mutex_init(&bdev->bd_mutex); + mutex_init(&bdev->bd_fsfreeze_mutex); + spin_lock_init(&bdev->bd_size_lock); + bdev->bd_disk = disk; + bdev->bd_partno = partno; + bdev->bd_inode = inode; + bdev->bd_bdi = &noop_backing_dev_info; +#ifdef CONFIG_SYSFS + INIT_LIST_HEAD(&bdev->bd_holder_disks); +#endif + bdev->bd_stats = alloc_percpu(struct disk_stats); + if (!bdev->bd_stats) { + iput(inode); + return NULL; + } + return bdev; } -static int bdev_set(struct inode *inode, void *data) +void bdev_add(struct block_device *bdev, dev_t dev) { - BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; - return 0; + bdev->bd_dev = dev; + bdev->bd_inode->i_rdev = dev; + bdev->bd_inode->i_ino = dev; + insert_inode_hash(bdev->bd_inode); } static struct block_device *bdget(dev_t dev) { - struct block_device *bdev; struct inode *inode; - inode = iget5_locked(blockdev_superblock, hash(dev), - bdev_test, bdev_set, &dev); - + inode = ilookup(blockdev_superblock, dev); if (!inode) return NULL; - - bdev = &BDEV_I(inode)->bdev; - - if (inode->i_state & I_NEW) { - spin_lock_init(&bdev->bd_size_lock); - bdev->bd_contains = NULL; - bdev->bd_super = NULL; - bdev->bd_inode = inode; - bdev->bd_part_count = 0; - inode->i_mode = S_IFBLK; - inode->i_rdev = dev; - inode->i_bdev = bdev; - inode->i_data.a_ops = &def_blk_aops; - mapping_set_gfp_mask(&inode->i_data, GFP_USER); - unlock_new_inode(inode); - } - return bdev; + return &BDEV_I(inode)->bdev; } /** * bdgrab -- Grab a reference to an already referenced block device * @bdev: Block device to grab a reference to. + * + * Returns the block_device with an additional reference when successful, + * or NULL if the inode is already beeing freed. */ struct block_device *bdgrab(struct block_device *bdev) { - ihold(bdev->bd_inode); + if (!igrab(bdev->bd_inode)) + return NULL; return bdev; } EXPORT_SYMBOL(bdgrab); -struct block_device *bdget_part(struct hd_struct *part) -{ - return bdget(part_devt(part)); -} - long nr_blockdev_pages(void) { struct inode *inode; @@ -953,67 +939,8 @@ void bdput(struct block_device *bdev) { iput(bdev->bd_inode); } - EXPORT_SYMBOL(bdput); -static struct block_device *bd_acquire(struct inode *inode) -{ - struct block_device *bdev; - - spin_lock(&bdev_lock); - bdev = inode->i_bdev; - if (bdev && !inode_unhashed(bdev->bd_inode)) { - bdgrab(bdev); - spin_unlock(&bdev_lock); - return bdev; - } - spin_unlock(&bdev_lock); - - /* - * i_bdev references block device inode that was already shut down - * (corresponding device got removed). Remove the reference and look - * up block device inode again just in case new device got - * reestablished under the same device number. - */ - if (bdev) - bd_forget(inode); - - bdev = bdget(inode->i_rdev); - if (bdev) { - spin_lock(&bdev_lock); - if (!inode->i_bdev) { - /* - * We take an additional reference to bd_inode, - * and it's released in clear_inode() of inode. - * So, we can access it via ->i_mapping always - * without igrab(). - */ - bdgrab(bdev); - inode->i_bdev = bdev; - inode->i_mapping = bdev->bd_inode->i_mapping; - } - spin_unlock(&bdev_lock); - } - return bdev; -} - -/* Call when you free inode */ - -void bd_forget(struct inode *inode) -{ - struct block_device *bdev = NULL; - - spin_lock(&bdev_lock); - if (!sb_is_blkdev_sb(inode->i_sb)) - bdev = inode->i_bdev; - inode->i_bdev = NULL; - inode->i_mapping = &inode->i_data; - spin_unlock(&bdev_lock); - - if (bdev) - bdput(bdev); -} - /** * bd_may_claim - test whether a block device can be claimed * @bdev: block device of interest @@ -1049,7 +976,6 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, /** * bd_prepare_to_claim - claim a block device * @bdev: block device of interest - * @whole: the whole device containing @bdev, may equal @bdev * @holder: holder trying to claim @bdev * * Claim @bdev. This function fails if @bdev is already claimed by another @@ -1059,9 +985,12 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, * RETURNS: * 0 if @bdev can be claimed, -EBUSY otherwise. */ -int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole, - void *holder) +int bd_prepare_to_claim(struct block_device *bdev, void *holder) { + struct block_device *whole = bdev_whole(bdev); + + if (WARN_ON_ONCE(!holder)) + return -EINVAL; retry: spin_lock(&bdev_lock); /* if someone else claimed, fail */ @@ -1089,27 +1018,6 @@ retry: } EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ -static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno) -{ - struct gendisk *disk = get_gendisk(bdev->bd_dev, partno); - - if (!disk) - return NULL; - /* - * Now that we hold gendisk reference we make sure bdev we looked up is - * not stale. If it is, it means device got removed and created before - * we looked up gendisk and we fail open in such case. Associating - * unhashed bdev with newly created gendisk could lead to two bdevs - * (and thus two independent caches) being associated with one device - * which is bad. - */ - if (inode_unhashed(bdev->bd_inode)) { - put_disk_and_module(disk); - return NULL; - } - return disk; -} - static void bd_clear_claiming(struct block_device *whole, void *holder) { lockdep_assert_held(&bdev_lock); @@ -1122,15 +1030,15 @@ static void bd_clear_claiming(struct block_device *whole, void *holder) /** * bd_finish_claiming - finish claiming of a block device * @bdev: block device of interest - * @whole: whole block device * @holder: holder that has claimed @bdev * * Finish exclusive open of a block device. Mark the device as exlusively * open by the holder and wake up all waiters for exclusive open to finish. */ -static void bd_finish_claiming(struct block_device *bdev, - struct block_device *whole, void *holder) +static void bd_finish_claiming(struct block_device *bdev, void *holder) { + struct block_device *whole = bdev_whole(bdev); + spin_lock(&bdev_lock); BUG_ON(!bd_may_claim(bdev, whole, holder)); /* @@ -1155,11 +1063,10 @@ static void bd_finish_claiming(struct block_device *bdev, * also used when exclusive open is not actually desired and we just needed * to block other exclusive openers for a while. */ -void bd_abort_claiming(struct block_device *bdev, struct block_device *whole, - void *holder) +void bd_abort_claiming(struct block_device *bdev, void *holder) { spin_lock(&bdev_lock); - bd_clear_claiming(whole, holder); + bd_clear_claiming(bdev_whole(bdev), holder); spin_unlock(&bdev_lock); } EXPORT_SYMBOL(bd_abort_claiming); @@ -1230,7 +1137,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) WARN_ON_ONCE(!bdev->bd_holder); /* FIXME: remove the following once add_disk() handles errors */ - if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) + if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) goto out_unlock; holder = bd_find_holder_disk(bdev, disk); @@ -1249,24 +1156,24 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) holder->disk = disk; holder->refcnt = 1; - ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); + ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); if (ret) goto out_free; - ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); + ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); if (ret) goto out_del; /* * bdev could be deleted beneath us which would implicitly destroy * the holder directory. Hold on to it. */ - kobject_get(bdev->bd_part->holder_dir); + kobject_get(bdev->bd_holder_dir); list_add(&holder->list, &bdev->bd_holder_disks); goto out_unlock; out_del: - del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); + del_symlink(disk->slave_dir, bdev_kobj(bdev)); out_free: kfree(holder); out_unlock: @@ -1294,10 +1201,9 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) holder = bd_find_holder_disk(bdev, disk); 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); - kobject_put(bdev->bd_part->holder_dir); + del_symlink(disk->slave_dir, bdev_kobj(bdev)); + del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); + kobject_put(bdev->bd_holder_dir); list_del_init(&holder->list); kfree(holder); } @@ -1307,77 +1213,6 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); #endif -/** - * check_disk_size_change - checks for disk size change and adjusts bdev size. - * @disk: struct gendisk to check - * @bdev: struct bdev to adjust. - * @verbose: if %true log a message about a size change if there is any - * - * This routine checks to see if the bdev size does not match the disk size - * and adjusts it if it differs. When shrinking the bdev size, its all caches - * are freed. - */ -static void check_disk_size_change(struct gendisk *disk, - struct block_device *bdev, bool verbose) -{ - loff_t disk_size, bdev_size; - - spin_lock(&bdev->bd_size_lock); - disk_size = (loff_t)get_capacity(disk) << 9; - bdev_size = i_size_read(bdev->bd_inode); - if (disk_size != bdev_size) { - if (verbose) { - printk(KERN_INFO - "%s: detected capacity change from %lld to %lld\n", - disk->disk_name, bdev_size, disk_size); - } - i_size_write(bdev->bd_inode, disk_size); - } - spin_unlock(&bdev->bd_size_lock); - - if (bdev_size > disk_size) { - if (__invalidate_device(bdev, false)) - pr_warn("VFS: busy inodes on resized disk %s\n", - disk->disk_name); - } -} - -/** - * revalidate_disk_size - checks for disk size change and adjusts bdev size. - * @disk: struct gendisk to check - * @verbose: if %true log a message about a size change if there is any - * - * This routine checks to see if the bdev size does not match the disk size - * and adjusts it if it differs. When shrinking the bdev size, its all caches - * are freed. - */ -void revalidate_disk_size(struct gendisk *disk, bool verbose) -{ - struct block_device *bdev; - - /* - * Hidden disks don't have associated bdev so there's no point in - * revalidating them. - */ - if (disk->flags & GENHD_FL_HIDDEN) - return; - - bdev = bdget_disk(disk, 0); - if (bdev) { - check_disk_size_change(disk, bdev, verbose); - bdput(bdev); - } -} -EXPORT_SYMBOL(revalidate_disk_size); - -void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors) -{ - spin_lock(&bdev->bd_size_lock); - i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); - spin_unlock(&bdev->bd_size_lock); -} -EXPORT_SYMBOL(bd_set_nr_sectors); - static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); int bdev_disk_changed(struct block_device *bdev, bool invalidate) @@ -1411,8 +1246,6 @@ rescan: disk->fops->revalidate_disk(disk); } - check_disk_size_change(disk, bdev, !invalidate); - if (get_capacity(disk)) { ret = blk_add_partitions(disk, bdev); if (ret == -EAGAIN) @@ -1439,71 +1272,19 @@ EXPORT_SYMBOL_GPL(bdev_disk_changed); * mutex_lock(part->bd_mutex) * mutex_lock_nested(whole->bd_mutex, 1) */ - -static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, - int for_part) +static int __blkdev_get(struct block_device *bdev, fmode_t mode) { - struct block_device *whole = NULL, *claiming = NULL; - struct gendisk *disk; - int ret; - int partno; - bool first_open = false, unblock_events = true, need_restart; - - restart: - need_restart = false; - ret = -ENXIO; - disk = bdev_get_gendisk(bdev, &partno); - if (!disk) - goto out; - - if (partno) { - whole = bdget_disk(disk, 0); - if (!whole) { - ret = -ENOMEM; - goto out_put_disk; - } - } - - if (!for_part && (mode & FMODE_EXCL)) { - WARN_ON_ONCE(!holder); - if (whole) - claiming = whole; - else - claiming = bdev; - ret = bd_prepare_to_claim(bdev, claiming, holder); - if (ret) - goto out_put_whole; - } + struct gendisk *disk = bdev->bd_disk; + int ret = 0; - disk_block_events(disk); - mutex_lock_nested(&bdev->bd_mutex, for_part); if (!bdev->bd_openers) { - first_open = true; - bdev->bd_disk = disk; - bdev->bd_contains = bdev; - bdev->bd_partno = partno; - - if (!partno) { - ret = -ENXIO; - bdev->bd_part = disk_get_part(disk, partno); - if (!bdev->bd_part) - goto out_clear; - + if (!bdev_is_partition(bdev)) { ret = 0; - if (disk->fops->open) { + if (disk->fops->open) ret = disk->fops->open(bdev, mode); - /* - * If we lost a race with 'disk' being deleted, - * try again. See md.c - */ - if (ret == -ERESTARTSYS) - need_restart = true; - } - if (!ret) { - bd_set_nr_sectors(bdev, get_capacity(disk)); + if (!ret) set_init_blocksize(bdev); - } /* * If the device is invalidated, rescan partition @@ -1516,28 +1297,33 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, bdev_disk_changed(bdev, ret == -ENOMEDIUM); if (ret) - goto out_clear; + return ret; } else { - BUG_ON(for_part); - ret = __blkdev_get(whole, mode, NULL, 1); - if (ret) - goto out_clear; - bdev->bd_contains = bdgrab(whole); - bdev->bd_part = disk_get_part(disk, partno); + struct block_device *whole = bdgrab(disk->part0); + + mutex_lock_nested(&whole->bd_mutex, 1); + ret = __blkdev_get(whole, mode); + if (ret) { + mutex_unlock(&whole->bd_mutex); + bdput(whole); + return ret; + } + whole->bd_part_count++; + mutex_unlock(&whole->bd_mutex); + if (!(disk->flags & GENHD_FL_UP) || - !bdev->bd_part || !bdev->bd_part->nr_sects) { - ret = -ENXIO; - goto out_clear; + !bdev_nr_sectors(bdev)) { + __blkdev_put(whole, mode, 1); + bdput(whole); + return -ENXIO; } - bd_set_nr_sectors(bdev, bdev->bd_part->nr_sects); set_init_blocksize(bdev); } if (bdev->bd_bdi == &noop_backing_dev_info) bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info); } else { - if (bdev->bd_contains == bdev) { - ret = 0; + if (!bdev_is_partition(bdev)) { if (bdev->bd_disk->fops->open) ret = bdev->bd_disk->fops->open(bdev, mode); /* the same as first opener case, read comment there */ @@ -1545,101 +1331,145 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, (!ret || ret == -ENOMEDIUM)) bdev_disk_changed(bdev, ret == -ENOMEDIUM); if (ret) - goto out_unlock_bdev; + return ret; } } bdev->bd_openers++; - if (for_part) - bdev->bd_part_count++; - if (claiming) - bd_finish_claiming(bdev, claiming, holder); + return 0; +} - /* - * Block event polling for write claims if requested. 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 (claiming && (mode & FMODE_WRITE) && !bdev->bd_write_holder && - (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { - bdev->bd_write_holder = true; - unblock_events = false; - } - mutex_unlock(&bdev->bd_mutex); +struct block_device *blkdev_get_no_open(dev_t dev) +{ + struct block_device *bdev; + struct gendisk *disk; - if (unblock_events) - disk_unblock_events(disk); + down_read(&bdev_lookup_sem); + bdev = bdget(dev); + if (!bdev) { + up_read(&bdev_lookup_sem); + blk_request_module(dev); + down_read(&bdev_lookup_sem); + + bdev = bdget(dev); + if (!bdev) + goto unlock; + } - /* only one opener holds refs to the module and disk */ - if (!first_open) - put_disk_and_module(disk); - if (whole) - bdput(whole); - return 0; + disk = bdev->bd_disk; + if (!kobject_get_unless_zero(&disk_to_dev(disk)->kobj)) + goto bdput; + if ((disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP) + goto put_disk; + if (!try_module_get(bdev->bd_disk->fops->owner)) + goto put_disk; + up_read(&bdev_lookup_sem); + return bdev; +put_disk: + put_disk(disk); +bdput: + bdput(bdev); +unlock: + up_read(&bdev_lookup_sem); + return NULL; +} - out_clear: - disk_put_part(bdev->bd_part); - bdev->bd_disk = NULL; - bdev->bd_part = NULL; - if (bdev != bdev->bd_contains) - __blkdev_put(bdev->bd_contains, mode, 1); - bdev->bd_contains = NULL; - out_unlock_bdev: - if (claiming) - bd_abort_claiming(bdev, claiming, holder); - mutex_unlock(&bdev->bd_mutex); - disk_unblock_events(disk); - out_put_whole: - if (whole) - bdput(whole); - out_put_disk: - put_disk_and_module(disk); - if (need_restart) - goto restart; - out: - return ret; +void blkdev_put_no_open(struct block_device *bdev) +{ + module_put(bdev->bd_disk->fops->owner); + put_disk(bdev->bd_disk); + bdput(bdev); } /** - * blkdev_get - open a block device - * @bdev: block_device to open + * 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 @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. + * Open the block device described by device number @dev. If @mode includes + * %FMODE_EXCL, the block device is opened with exclusive access. Specifying + * %FMODE_EXCL with a %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. + * Use this interface 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. Everything else should use blkdev_get_by_path(). * * CONTEXT: * Might sleep. * * RETURNS: - * 0 on success, -errno on failure. + * Reference to the block_device on success, ERR_PTR(-errno) on failure. */ -static int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) +struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) { - int ret, perm = 0; + bool unblock_events = true; + struct block_device *bdev; + struct gendisk *disk; + int ret; - if (mode & FMODE_READ) - perm |= MAY_READ; - if (mode & FMODE_WRITE) - perm |= MAY_WRITE; - ret = devcgroup_inode_permission(bdev->bd_inode, perm); + ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, + MAJOR(dev), MINOR(dev), + ((mode & FMODE_READ) ? DEVCG_ACC_READ : 0) | + ((mode & FMODE_WRITE) ? DEVCG_ACC_WRITE : 0)); if (ret) - goto bdput; + return ERR_PTR(ret); + + /* + * If we lost a race with 'disk' being deleted, try again. See md.c. + */ +retry: + bdev = blkdev_get_no_open(dev); + if (!bdev) + return ERR_PTR(-ENXIO); + disk = bdev->bd_disk; + + if (mode & FMODE_EXCL) { + ret = bd_prepare_to_claim(bdev, holder); + if (ret) + goto put_blkdev; + } + + disk_block_events(disk); - ret =__blkdev_get(bdev, mode, holder, 0); + mutex_lock(&bdev->bd_mutex); + ret =__blkdev_get(bdev, mode); if (ret) - goto bdput; - return 0; + goto abort_claiming; + if (mode & FMODE_EXCL) { + bd_finish_claiming(bdev, holder); -bdput: - bdput(bdev); - return ret; + /* + * Block event polling for write claims if requested. 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 ((mode & FMODE_WRITE) && !bdev->bd_write_holder && + (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { + bdev->bd_write_holder = true; + unblock_events = false; + } + } + mutex_unlock(&bdev->bd_mutex); + + if (unblock_events) + disk_unblock_events(disk); + return bdev; + +abort_claiming: + if (mode & FMODE_EXCL) + bd_abort_claiming(bdev, holder); + mutex_unlock(&bdev->bd_mutex); + disk_unblock_events(disk); +put_blkdev: + blkdev_put_no_open(bdev); + if (ret == -ERESTARTSYS) + goto retry; + return ERR_PTR(ret); } +EXPORT_SYMBOL(blkdev_get_by_dev); /** * blkdev_get_by_path - open a block device by name @@ -1647,32 +1477,30 @@ bdput: * @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. + * Open the block device described by the device file at @path. If @mode + * includes %FMODE_EXCL, the block device is opened with exclusive access. + * Specifying %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may + * nest for the same @holder. * * CONTEXT: * Might sleep. * * RETURNS: - * Pointer to block_device on success, ERR_PTR(-errno) on failure. + * Reference to the 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; + dev_t dev; + int error; - err = blkdev_get(bdev, mode, holder); - if (err) - return ERR_PTR(err); + error = lookup_bdev(path, &dev); + if (error) + return ERR_PTR(error); - if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { + bdev = blkdev_get_by_dev(dev, mode, holder); + if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) { blkdev_put(bdev, mode); return ERR_PTR(-EACCES); } @@ -1681,45 +1509,6 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, } 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; @@ -1741,14 +1530,12 @@ static int blkdev_open(struct inode * inode, struct file * filp) if ((filp->f_flags & O_ACCMODE) == 3) filp->f_mode |= FMODE_WRITE_IOCTL; - bdev = bd_acquire(inode); - if (bdev == NULL) - return -ENOMEM; - + bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); filp->f_mapping = bdev->bd_inode->i_mapping; filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); - - return blkdev_get(bdev, filp->f_mode, filp); + return 0; } static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) @@ -1774,34 +1561,28 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) WARN_ON_ONCE(bdev->bd_holders); sync_blockdev(bdev); kill_bdev(bdev); - bdev_write_inode(bdev); + if (bdev_is_partition(bdev)) + victim = bdev_whole(bdev); } - if (bdev->bd_contains == bdev) { - if (disk->fops->release) - disk->fops->release(disk, mode); - } - if (!bdev->bd_openers) { - disk_put_part(bdev->bd_part); - bdev->bd_part = NULL; - bdev->bd_disk = NULL; - if (bdev != bdev->bd_contains) - victim = bdev->bd_contains; - bdev->bd_contains = NULL; - - put_disk_and_module(disk); - } + + if (!bdev_is_partition(bdev) && disk->fops->release) + disk->fops->release(disk, mode); mutex_unlock(&bdev->bd_mutex); - bdput(bdev); - if (victim) + if (victim) { __blkdev_put(victim, mode, 1); + bdput(victim); + } } void blkdev_put(struct block_device *bdev, fmode_t mode) { + struct gendisk *disk = bdev->bd_disk; + mutex_lock(&bdev->bd_mutex); if (mode & FMODE_EXCL) { + struct block_device *whole = bdev_whole(bdev); bool bdev_free; /* @@ -1812,13 +1593,12 @@ void blkdev_put(struct block_device *bdev, fmode_t mode) spin_lock(&bdev_lock); WARN_ON_ONCE(--bdev->bd_holders < 0); - WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); + WARN_ON_ONCE(--whole->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; + if (!whole->bd_holders) + whole->bd_holder = NULL; spin_unlock(&bdev_lock); @@ -1827,7 +1607,7 @@ void blkdev_put(struct block_device *bdev, fmode_t mode) * unblock evpoll if it was a write holder. */ if (bdev_free && bdev->bd_write_holder) { - disk_unblock_events(bdev->bd_disk); + disk_unblock_events(disk); bdev->bd_write_holder = false; } } @@ -1837,11 +1617,11 @@ void blkdev_put(struct block_device *bdev, fmode_t mode) * event. This is to ensure detection of media removal commanded * from userland - e.g. eject(1). */ - disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE); - + disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE); mutex_unlock(&bdev->bd_mutex); __blkdev_put(bdev, mode, 0); + blkdev_put_no_open(bdev); } EXPORT_SYMBOL(blkdev_put); @@ -2054,37 +1834,32 @@ const struct file_operations def_blk_fops = { * namespace if possible and return it. Return ERR_PTR(error) * otherwise. */ -struct block_device *lookup_bdev(const char *pathname) +int lookup_bdev(const char *pathname, dev_t *dev) { - struct block_device *bdev; struct inode *inode; struct path path; int error; if (!pathname || !*pathname) - return ERR_PTR(-EINVAL); + return -EINVAL; error = kern_path(pathname, LOOKUP_FOLLOW, &path); if (error) - return ERR_PTR(error); + return error; inode = d_backing_inode(path.dentry); error = -ENOTBLK; if (!S_ISBLK(inode->i_mode)) - goto fail; + goto out_path_put; error = -EACCES; if (!may_open_dev(&path)) - goto fail; - error = -ENOMEM; - bdev = bd_acquire(inode); - if (!bdev) - goto fail; -out: + goto out_path_put; + + *dev = inode->i_rdev; + error = 0; +out_path_put: path_put(&path); - return bdev; -fail: - bdev = ERR_PTR(error); - goto out; + return error; } EXPORT_SYMBOL(lookup_bdev); |