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| author | Tejun Heo <tj@kernel.org> | 2008-11-05 10:21:06 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-11-06 08:41:56 +0100 |
| commit | 89f97496e81d2112b5e41416fe3020688c443818 (patch) | |
| tree | e78122150d550bf644ca1a96916a5880823d3e04 /fs/block_dev.c | |
| parent | 561920a0d2bb6d63343e83acfd784c0a77bd28d1 (diff) | |
| download | lwn-89f97496e81d2112b5e41416fe3020688c443818.tar.gz lwn-89f97496e81d2112b5e41416fe3020688c443818.zip | |
block: fix __blkdev_get() for removable devices
Commit 0762b8bde9729f10f8e6249809660ff2ec3ad735 moved disk_get_part()
in front of recursive get on the whole disk, which caused removable
devices to try disk_get_part() before rescanning after a new media is
inserted, which might fail legit open attempts or give the old
partition.
This patch fixes the problem by moving disk_get_part() after
__blkdev_get() on the whole disk.
This problem was spotted by Borislav Petkov.
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 88a776fa0ef6..db831efbdbbd 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -986,7 +986,6 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) { struct gendisk *disk; - struct hd_struct *part = NULL; int ret; int partno; int perm = 0; @@ -1004,24 +1003,25 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) return ret; } - ret = -ENXIO; - lock_kernel(); + ret = -ENXIO; disk = get_gendisk(bdev->bd_dev, &partno); if (!disk) goto out_unlock_kernel; - part = disk_get_part(disk, partno); - if (!part) - goto out_unlock_kernel; mutex_lock_nested(&bdev->bd_mutex, for_part); if (!bdev->bd_openers) { bdev->bd_disk = disk; - bdev->bd_part = part; bdev->bd_contains = bdev; if (!partno) { struct backing_dev_info *bdi; + + ret = -ENXIO; + bdev->bd_part = disk_get_part(disk, partno); + if (!bdev->bd_part) + goto out_clear; + if (disk->fops->open) { ret = disk->fops->open(bdev, mode); if (ret) @@ -1049,18 +1049,17 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) bdev->bd_contains = whole; bdev->bd_inode->i_data.backing_dev_info = whole->bd_inode->i_data.backing_dev_info; + bdev->bd_part = disk_get_part(disk, partno); if (!(disk->flags & GENHD_FL_UP) || - !part || !part->nr_sects) { + !bdev->bd_part || !bdev->bd_part->nr_sects) { ret = -ENXIO; goto out_clear; } - bd_set_size(bdev, (loff_t)part->nr_sects << 9); + bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); } } else { - disk_put_part(part); put_disk(disk); module_put(disk->fops->owner); - part = NULL; disk = NULL; if (bdev->bd_contains == bdev) { if (bdev->bd_disk->fops->open) { @@ -1080,6 +1079,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) return 0; out_clear: + disk_put_part(bdev->bd_part); bdev->bd_disk = NULL; bdev->bd_part = NULL; bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info; @@ -1091,7 +1091,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) out_unlock_kernel: unlock_kernel(); - disk_put_part(part); if (disk) module_put(disk->fops->owner); put_disk(disk); |