diff options
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 402 |
1 files changed, 139 insertions, 263 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 69bf2fb6f7cd..8ae833e00443 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -19,7 +19,6 @@ #include <linux/module.h> #include <linux/blkpg.h> #include <linux/magic.h> -#include <linux/dax.h> #include <linux/buffer_head.h> #include <linux/swap.h> #include <linux/pagevec.h> @@ -34,6 +33,7 @@ #include <linux/task_io_accounting_ops.h> #include <linux/falloc.h> #include <linux/uaccess.h> +#include <linux/suspend.h> #include "internal.h" struct bdev_inode { @@ -75,7 +75,7 @@ static void bdev_write_inode(struct block_device *bdev) } /* Kill _all_ buffers and pagecache , dirty or not.. */ -void kill_bdev(struct block_device *bdev) +static void kill_bdev(struct block_device *bdev) { struct address_space *mapping = bdev->bd_inode->i_mapping; @@ -84,8 +84,7 @@ void kill_bdev(struct block_device *bdev) invalidate_bh_lrus(); truncate_inode_pages(mapping, 0); -} -EXPORT_SYMBOL(kill_bdev); +} /* Invalidate clean unused buffers and pagecache. */ void invalidate_bdev(struct block_device *bdev) @@ -106,16 +105,7 @@ EXPORT_SYMBOL(invalidate_bdev); static void set_init_blocksize(struct block_device *bdev) { - unsigned bsize = bdev_logical_block_size(bdev); - loff_t size = i_size_read(bdev->bd_inode); - - while (bsize < PAGE_SIZE) { - if (size & bsize) - break; - bsize <<= 1; - } - bdev->bd_block_size = bsize; - bdev->bd_inode->i_blkbits = blksize_bits(bsize); + bdev->bd_inode->i_blkbits = blksize_bits(bdev_logical_block_size(bdev)); } int set_blocksize(struct block_device *bdev, int size) @@ -129,9 +119,8 @@ int set_blocksize(struct block_device *bdev, int size) return -EINVAL; /* Don't change the size if it is same as current */ - if (bdev->bd_block_size != size) { + if (bdev->bd_inode->i_blkbits != blksize_bits(size)) { sync_blockdev(bdev); - bdev->bd_block_size = size; bdev->bd_inode->i_blkbits = blksize_bits(size); kill_bdev(bdev); } @@ -255,7 +244,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, break; if (!(iocb->ki_flags & IOCB_HIPRI) || !blk_poll(bdev_get_queue(bdev), qc, true)) - io_schedule(); + blk_io_schedule(); } __set_current_state(TASK_RUNNING); @@ -449,7 +438,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) if (!(iocb->ki_flags & IOCB_HIPRI) || !blk_poll(bdev_get_queue(bdev), qc, true)) - io_schedule(); + blk_io_schedule(); } __set_current_state(TASK_RUNNING); @@ -614,10 +603,9 @@ static int blkdev_readpage(struct file * file, struct page * page) return block_read_full_page(page, blkdev_get_block); } -static int blkdev_readpages(struct file *file, struct address_space *mapping, - struct list_head *pages, unsigned nr_pages) +static void blkdev_readahead(struct readahead_control *rac) { - return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block); + mpage_readahead(rac, blkdev_get_block); } static int blkdev_write_begin(struct file *file, struct address_space *mapping, @@ -672,7 +660,7 @@ int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) * i_mutex and doing so causes performance issues with concurrent * O_SYNC writers to a block device. */ - error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); + error = blkdev_issue_flush(bdev, GFP_KERNEL); if (error == -EOPNOTSUPP) error = 0; @@ -705,15 +693,14 @@ int bdev_read_page(struct block_device *bdev, sector_t sector, if (!ops->rw_page || bdev_get_integrity(bdev)) return result; - result = blk_queue_enter(bdev->bd_queue, 0); + result = blk_queue_enter(bdev->bd_disk->queue, 0); if (result) return result; result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, REQ_OP_READ); - blk_queue_exit(bdev->bd_queue); + blk_queue_exit(bdev->bd_disk->queue); return result; } -EXPORT_SYMBOL_GPL(bdev_read_page); /** * bdev_write_page() - Start writing a page to a block device @@ -742,7 +729,7 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, if (!ops->rw_page || bdev_get_integrity(bdev)) return -EOPNOTSUPP; - result = blk_queue_enter(bdev->bd_queue, 0); + result = blk_queue_enter(bdev->bd_disk->queue, 0); if (result) return result; @@ -755,10 +742,9 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, clean_page_buffers(page); unlock_page(page); } - blk_queue_exit(bdev->bd_queue); + blk_queue_exit(bdev->bd_disk->queue); return result; } -EXPORT_SYMBOL_GPL(bdev_write_page); /* * pseudo-fs @@ -787,7 +773,6 @@ static void init_once(void *foo) memset(bdev, 0, sizeof(*bdev)); mutex_init(&bdev->bd_mutex); - INIT_LIST_HEAD(&bdev->bd_list); #ifdef CONFIG_SYSFS INIT_LIST_HEAD(&bdev->bd_holder_disks); #endif @@ -803,9 +788,6 @@ static void bdev_evict_inode(struct inode *inode) truncate_inode_pages_final(&inode->i_data); invalidate_inode_buffers(inode); /* is it needed here? */ clear_inode(inode); - spin_lock(&bdev_lock); - list_del_init(&bdev->bd_list); - spin_unlock(&bdev_lock); /* Detach inode from wb early as bdi_put() may free bdi->wb */ inode_detach_wb(inode); if (bdev->bd_bdi != &noop_backing_dev_info) { @@ -880,23 +862,6 @@ static int bdev_set(struct inode *inode, void *data) return 0; } -static LIST_HEAD(all_bdevs); - -/* - * If there is a bdev inode for this device, unhash it so that it gets evicted - * as soon as last inode reference is dropped. - */ -void bdev_unhash_inode(dev_t dev) -{ - struct inode *inode; - - inode = ilookup5(blockdev_superblock, hash(dev), bdev_test, &dev); - if (inode) { - remove_inode_hash(inode); - iput(inode); - } -} - struct block_device *bdget(dev_t dev) { struct block_device *bdev; @@ -914,7 +879,6 @@ struct block_device *bdget(dev_t dev) bdev->bd_contains = NULL; bdev->bd_super = NULL; bdev->bd_inode = inode; - bdev->bd_block_size = i_blocksize(inode); bdev->bd_part_count = 0; bdev->bd_invalidated = 0; inode->i_mode = S_IFBLK; @@ -922,9 +886,6 @@ struct block_device *bdget(dev_t dev) inode->i_bdev = bdev; inode->i_data.a_ops = &def_blk_aops; mapping_set_gfp_mask(&inode->i_data, GFP_USER); - spin_lock(&bdev_lock); - list_add(&bdev->bd_list, &all_bdevs); - spin_unlock(&bdev_lock); unlock_new_inode(inode); } return bdev; @@ -945,13 +906,14 @@ EXPORT_SYMBOL(bdgrab); long nr_blockdev_pages(void) { - struct block_device *bdev; + struct inode *inode; long ret = 0; - spin_lock(&bdev_lock); - list_for_each_entry(bdev, &all_bdevs, bd_list) { - ret += bdev->bd_inode->i_mapping->nrpages; - } - spin_unlock(&bdev_lock); + + spin_lock(&blockdev_superblock->s_inode_list_lock); + list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) + ret += inode->i_mapping->nrpages; + spin_unlock(&blockdev_superblock->s_inode_list_lock); + return ret; } @@ -1053,30 +1015,28 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, } /** - * bd_prepare_to_claim - prepare to claim a block device + * 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 * - * Prepare to claim @bdev. This function fails if @bdev is already - * claimed by another holder and waits if another claiming is in - * progress. This function doesn't actually claim. On successful - * return, the caller has ownership of bd_claiming and bd_holder[s]. - * - * CONTEXT: - * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab - * it multiple times. + * Claim @bdev. This function fails if @bdev is already claimed by another + * holder and waits if another claiming is in progress. return, the caller + * has ownership of bd_claiming and bd_holder[s]. * * RETURNS: * 0 if @bdev can be claimed, -EBUSY otherwise. */ -static int bd_prepare_to_claim(struct block_device *bdev, - struct block_device *whole, void *holder) +int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole, + void *holder) { retry: + spin_lock(&bdev_lock); /* if someone else claimed, fail */ - if (!bd_may_claim(bdev, whole, holder)) + if (!bd_may_claim(bdev, whole, holder)) { + spin_unlock(&bdev_lock); return -EBUSY; + } /* if claiming is already in progress, wait for it to finish */ if (whole->bd_claiming) { @@ -1087,13 +1047,15 @@ retry: spin_unlock(&bdev_lock); schedule(); finish_wait(wq, &wait); - spin_lock(&bdev_lock); goto retry; } /* yay, all mine */ + whole->bd_claiming = holder; + spin_unlock(&bdev_lock); return 0; } +EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno) { @@ -1116,78 +1078,6 @@ static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno) return disk; } -/** - * bd_start_claiming - start claiming a block device - * @bdev: block device of interest - * @holder: holder trying to claim @bdev - * - * @bdev is about to be opened exclusively. Check @bdev can be opened - * exclusively and mark that an exclusive open is in progress. Each - * successful call to this function must be matched with a call to - * either bd_finish_claiming() or bd_abort_claiming() (which do not - * fail). - * - * This function is used to gain exclusive access to the block device - * without actually causing other exclusive open attempts to fail. It - * should be used when the open sequence itself requires exclusive - * access but may subsequently fail. - * - * CONTEXT: - * Might sleep. - * - * RETURNS: - * Pointer to the block device containing @bdev on success, ERR_PTR() - * value on failure. - */ -struct block_device *bd_start_claiming(struct block_device *bdev, void *holder) -{ - struct gendisk *disk; - struct block_device *whole; - int partno, err; - - might_sleep(); - - /* - * @bdev might not have been initialized properly yet, look up - * and grab the outer block device the hard way. - */ - disk = bdev_get_gendisk(bdev, &partno); - if (!disk) - return ERR_PTR(-ENXIO); - - /* - * Normally, @bdev should equal what's returned from bdget_disk() - * if partno is 0; however, some drivers (floppy) use multiple - * bdev's for the same physical device and @bdev may be one of the - * aliases. Keep @bdev if partno is 0. This means claimer - * tracking is broken for those devices but it has always been that - * way. - */ - if (partno) - whole = bdget_disk(disk, 0); - else - whole = bdgrab(bdev); - - put_disk_and_module(disk); - if (!whole) - return ERR_PTR(-ENOMEM); - - /* prepare to claim, if successful, mark claiming in progress */ - spin_lock(&bdev_lock); - - err = bd_prepare_to_claim(bdev, whole, holder); - if (err == 0) { - whole->bd_claiming = holder; - spin_unlock(&bdev_lock); - return whole; - } else { - spin_unlock(&bdev_lock); - bdput(whole); - return ERR_PTR(err); - } -} -EXPORT_SYMBOL(bd_start_claiming); - static void bd_clear_claiming(struct block_device *whole, void *holder) { lockdep_assert_held(&bdev_lock); @@ -1200,14 +1090,14 @@ 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 (returned from bd_start_claiming()) + * @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. */ -void bd_finish_claiming(struct block_device *bdev, struct block_device *whole, - void *holder) +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)); @@ -1222,12 +1112,11 @@ void bd_finish_claiming(struct block_device *bdev, struct block_device *whole, bd_clear_claiming(whole, holder); spin_unlock(&bdev_lock); } -EXPORT_SYMBOL(bd_finish_claiming); /** * bd_abort_claiming - abort claiming of a block device * @bdev: block device of interest - * @whole: whole block device (returned from bd_start_claiming()) + * @whole: whole block device * @holder: holder that has claimed @bdev * * Abort claiming of a block device when the exclusive open failed. This can be @@ -1387,26 +1276,6 @@ EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); #endif /** - * flush_disk - invalidates all buffer-cache entries on a disk - * - * @bdev: struct block device to be flushed - * @kill_dirty: flag to guide handling of dirty inodes - * - * Invalidates all buffer-cache entries on a disk. It should be called - * when a disk has been changed -- either by a media change or online - * resize. - */ -static void flush_disk(struct block_device *bdev, bool kill_dirty) -{ - if (__invalidate_device(bdev, kill_dirty)) { - printk(KERN_WARNING "VFS: busy inodes on changed media or " - "resized disk %s\n", - bdev->bd_disk ? bdev->bd_disk->disk_name : ""); - } - bdev->bd_invalidated = 1; -} - -/** * check_disk_size_change - checks for disk size change and adjusts bdev size. * @disk: struct gendisk to check * @bdev: struct bdev to adjust. @@ -1430,8 +1299,9 @@ static void check_disk_size_change(struct gendisk *disk, disk->disk_name, bdev_size, disk_size); } i_size_write(bdev->bd_inode, disk_size); - if (bdev_size > disk_size) - flush_disk(bdev, false); + if (bdev_size > disk_size && __invalidate_device(bdev, false)) + pr_warn("VFS: busy inodes on resized disk %s\n", + disk->disk_name); } bdev->bd_invalidated = 0; } @@ -1490,7 +1360,10 @@ int check_disk_change(struct block_device *bdev) if (!(events & DISK_EVENT_MEDIA_CHANGE)) return 0; - flush_disk(bdev, true); + if (__invalidate_device(bdev, true)) + pr_warn("VFS: busy inodes on changed media %s\n", + disk->disk_name); + bdev->bd_invalidated = 1; if (bdops->revalidate_disk) bdops->revalidate_disk(bdev->bd_disk); return 1; @@ -1516,14 +1389,26 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate) lockdep_assert_held(&bdev->bd_mutex); rescan: - ret = blk_drop_partitions(disk, bdev); + ret = blk_drop_partitions(bdev); if (ret) return ret; - if (invalidate) - set_capacity(disk, 0); - else if (disk->fops->revalidate_disk) - disk->fops->revalidate_disk(disk); + /* + * Historically we only set the capacity to zero for devices that + * support partitions (independ of actually having partitions created). + * Doing that is rather inconsistent, but changing it broke legacy + * udisks polling for legacy ide-cdrom devices. Use the crude check + * below to get the sane behavior for most device while not breaking + * userspace for this particular setup. + */ + if (invalidate) { + if (disk_part_scan_enabled(disk) || + !(disk->flags & GENHD_FL_REMOVABLE)) + set_capacity(disk, 0); + } else { + if (disk->fops->revalidate_disk) + disk->fops->revalidate_disk(disk); + } check_disk_size_change(disk, bdev, !invalidate); @@ -1554,13 +1439,15 @@ EXPORT_SYMBOL_GPL(bdev_disk_changed); * mutex_lock_nested(whole->bd_mutex, 1) */ -static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) +static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, + int for_part) { + struct block_device *whole = NULL, *claiming = NULL; struct gendisk *disk; int ret; int partno; int perm = 0; - bool first_open = false; + bool first_open = false, unblock_events = true, need_restart; if (mode & FMODE_READ) perm |= MAY_READ; @@ -1571,25 +1458,41 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) */ if (!for_part) { ret = devcgroup_inode_permission(bdev->bd_inode, perm); - if (ret != 0) { - bdput(bdev); + if (ret != 0) return ret; - } } 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; + } + 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_queue = disk->queue; bdev->bd_contains = bdev; bdev->bd_partno = partno; @@ -1602,20 +1505,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) ret = 0; if (disk->fops->open) { ret = disk->fops->open(bdev, mode); - if (ret == -ERESTARTSYS) { - /* Lost a race with 'disk' being - * deleted, try again. - * See md.c - */ - disk_put_part(bdev->bd_part); - bdev->bd_part = NULL; - bdev->bd_disk = NULL; - bdev->bd_queue = NULL; - mutex_unlock(&bdev->bd_mutex); - disk_unblock_events(disk); - put_disk_and_module(disk); - goto restart; - } + /* + * If we lost a race with 'disk' being deleted, + * try again. See md.c + */ + if (ret == -ERESTARTSYS) + need_restart = true; } if (!ret) { @@ -1636,16 +1531,11 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) if (ret) goto out_clear; } else { - struct block_device *whole; - whole = bdget_disk(disk, 0); - ret = -ENOMEM; - if (!whole) - goto out_clear; BUG_ON(for_part); - ret = __blkdev_get(whole, mode, 1); + ret = __blkdev_get(whole, mode, NULL, 1); if (ret) goto out_clear; - bdev->bd_contains = whole; + bdev->bd_contains = bdgrab(whole); bdev->bd_part = disk_get_part(disk, partno); if (!(disk->flags & GENHD_FL_UP) || !bdev->bd_part || !bdev->bd_part->nr_sects) { @@ -1674,28 +1564,52 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_openers++; if (for_part) bdev->bd_part_count++; + if (claiming) + bd_finish_claiming(bdev, claiming, holder); + + /* + * 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); - disk_unblock_events(disk); + + if (unblock_events) + disk_unblock_events(disk); + /* only one opener holds refs to the module and disk */ if (!first_open) put_disk_and_module(disk); + if (whole) + bdput(whole); return 0; out_clear: disk_put_part(bdev->bd_part); bdev->bd_disk = NULL; bdev->bd_part = NULL; - bdev->bd_queue = 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: - bdput(bdev); - return ret; } @@ -1720,47 +1634,11 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) */ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) { - 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); - - if (whole) { - struct gendisk *disk = whole->bd_disk; - - /* finish claiming */ - mutex_lock(&bdev->bd_mutex); - if (!res) - bd_finish_claiming(bdev, whole, holder); - else - bd_abort_claiming(bdev, whole, holder); - /* - * 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 (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder && - (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { - bdev->bd_write_holder = true; - disk_block_events(disk); - } - - mutex_unlock(&bdev->bd_mutex); - bdput(whole); - } - + res =__blkdev_get(bdev, mode, holder, 0); + if (res) + bdput(bdev); return res; } EXPORT_SYMBOL(blkdev_get); @@ -1856,7 +1734,7 @@ static int blkdev_open(struct inode * inode, struct file * filp) */ filp->f_flags |= O_LARGEFILE; - filp->f_mode |= FMODE_NOWAIT; + filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; if (filp->f_flags & O_NDELAY) filp->f_mode |= FMODE_NDELAY; @@ -1880,6 +1758,16 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) struct gendisk *disk = bdev->bd_disk; struct block_device *victim = NULL; + /* + * Sync early if it looks like we're the last one. If someone else + * opens the block device between now and the decrement of bd_openers + * then we did a sync that we didn't need to, but that's not the end + * of the world and we want to avoid long (could be several minute) + * syncs while holding the mutex. + */ + if (bdev->bd_openers == 1) + sync_blockdev(bdev); + mutex_lock_nested(&bdev->bd_mutex, for_part); if (for_part) bdev->bd_part_count--; @@ -2001,7 +1889,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) if (bdev_read_only(I_BDEV(bd_inode))) return -EPERM; - if (IS_SWAPFILE(bd_inode)) + if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode)) return -ETXTBSY; if (!iov_iter_count(from)) @@ -2062,7 +1950,7 @@ static int blkdev_writepages(struct address_space *mapping, static const struct address_space_operations def_blk_aops = { .readpage = blkdev_readpage, - .readpages = blkdev_readpages, + .readahead = blkdev_readahead, .writepage = blkdev_writepage, .write_begin = blkdev_write_begin, .write_end = blkdev_write_end, @@ -2160,18 +2048,6 @@ const struct file_operations def_blk_fops = { .fallocate = blkdev_fallocate, }; -int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) -{ - int res; - mm_segment_t old_fs = get_fs(); - set_fs(KERNEL_DS); - res = blkdev_ioctl(bdev, 0, cmd, arg); - set_fs(old_fs); - return res; -} - -EXPORT_SYMBOL(ioctl_by_bdev); - /** * lookup_bdev - lookup a struct block_device by name * @pathname: special file representing the block device |