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authorTejun Heo <tj@kernel.org>2011-04-21 20:54:45 +0200
committerJens Axboe <jaxboe@fusionio.com>2011-04-21 20:54:45 +0200
commit1196f8b814f32cd04df334abf47648c2a9fd8324 (patch)
tree851592da601be9fe51903a49c8da460fab69b487
parentea6949b66d084a197dd7f243b72e216a71d9f2ca (diff)
block: rescan partitions on invalidated devices on -ENOMEDIA too
__blkdev_get() doesn't rescan partitions if disk->fops->open() fails, which leads to ghost partition devices lingering after medimum removal is known to both the kernel and userland. The behavior also creates a subtle inconsistency where O_NONBLOCK open, which doesn't fail even if there's no medium, clears the ghots partitions, which is exploited to work around the problem from userland. Fix it by updating __blkdev_get() to issue partition rescan after -ENOMEDIA too. This was reported in the following bz. https://bugzilla.kernel.org/show_bug.cgi?id=13029 Note for stable: 2.6.38 and later only Cc: stable@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: David Zeuthen <zeuthen@gmail.com> Reported-by: Martin Pitt <martin.pitt@ubuntu.com> Reported-by: Kay Sievers <kay.sievers@vrfy.org> Tested-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
-rw-r--r--fs/block_dev.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 5147bdd3b8e..257b00e9842 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1102,6 +1102,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
if (!bdev->bd_part)
goto out_clear;
+ ret = 0;
if (disk->fops->open) {
ret = disk->fops->open(bdev, mode);
if (ret == -ERESTARTSYS) {
@@ -1118,9 +1119,18 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
put_disk(disk);
goto restart;
}
- if (ret)
- goto out_clear;
}
+ /*
+ * If the device is invalidated, rescan partition
+ * if open succeeded or failed with -ENOMEDIUM.
+ * The latter is necessary to prevent ghost
+ * partitions on a removed medium.
+ */
+ if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM))
+ rescan_partitions(disk, bdev);
+ if (ret)
+ goto out_clear;
+
if (!bdev->bd_openers) {
bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
bdi = blk_get_backing_dev_info(bdev);
@@ -1128,8 +1138,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
bdi = &default_backing_dev_info;
bdev_inode_switch_bdi(bdev->bd_inode, bdi);
}
- if (bdev->bd_invalidated)
- rescan_partitions(disk, bdev);
} else {
struct block_device *whole;
whole = bdget_disk(disk, 0);
@@ -1153,13 +1161,14 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
}
} else {
if (bdev->bd_contains == bdev) {
- if (bdev->bd_disk->fops->open) {
+ ret = 0;
+ if (bdev->bd_disk->fops->open)
ret = bdev->bd_disk->fops->open(bdev, mode);
- if (ret)
- goto out_unlock_bdev;
- }
- if (bdev->bd_invalidated)
+ /* the same as first opener case, read comment there */
+ if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM))
rescan_partitions(bdev->bd_disk, bdev);
+ if (ret)
+ goto out_unlock_bdev;
}
/* only one opener holds refs to the module and disk */
module_put(disk->fops->owner);