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Diffstat (limited to 'fs/block_dev.c')
-rw-r--r--fs/block_dev.c123
1 files changed, 93 insertions, 30 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index fe3f59c14a0..88928701959 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -432,6 +432,9 @@ static void init_once(void *foo)
mutex_init(&bdev->bd_mutex);
INIT_LIST_HEAD(&bdev->bd_inodes);
INIT_LIST_HEAD(&bdev->bd_list);
+#ifdef CONFIG_SYSFS
+ INIT_LIST_HEAD(&bdev->bd_holder_disks);
+#endif
inode_init_once(&ei->vfs_inode);
/* Initialize mutex for freeze. */
mutex_init(&bdev->bd_fsfreeze_mutex);
@@ -779,6 +782,23 @@ static struct block_device *bd_start_claiming(struct block_device *bdev,
}
#ifdef CONFIG_SYSFS
+struct bd_holder_disk {
+ struct list_head list;
+ struct gendisk *disk;
+ int refcnt;
+};
+
+static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
+ struct gendisk *disk)
+{
+ struct bd_holder_disk *holder;
+
+ list_for_each_entry(holder, &bdev->bd_holder_disks, list)
+ if (holder->disk == disk)
+ return holder;
+ return NULL;
+}
+
static int add_symlink(struct kobject *from, struct kobject *to)
{
return sysfs_create_link(from, to, kobject_name(to));
@@ -794,6 +814,8 @@ static void del_symlink(struct kobject *from, struct kobject *to)
* @bdev: the claimed slave bdev
* @disk: the holding disk
*
+ * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
+ *
* This functions creates the following sysfs symlinks.
*
* - from "slaves" directory of the holder @disk to the claimed @bdev
@@ -817,61 +839,104 @@ static void del_symlink(struct kobject *from, struct kobject *to)
*/
int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
+ struct bd_holder_disk *holder;
int ret = 0;
mutex_lock(&bdev->bd_mutex);
- WARN_ON_ONCE(!bdev->bd_holder || bdev->bd_holder_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))
goto out_unlock;
- ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- if (ret)
+ holder = bd_find_holder_disk(bdev, disk);
+ if (holder) {
+ holder->refcnt++;
goto out_unlock;
+ }
- ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
- if (ret) {
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ holder = kzalloc(sizeof(*holder), GFP_KERNEL);
+ if (!holder) {
+ ret = -ENOMEM;
goto out_unlock;
}
- bdev->bd_holder_disk = disk;
+ INIT_LIST_HEAD(&holder->list);
+ holder->disk = disk;
+ holder->refcnt = 1;
+
+ ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ if (ret)
+ goto out_free;
+
+ ret = add_symlink(bdev->bd_part->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);
+
+ 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);
+out_free:
+ kfree(holder);
out_unlock:
mutex_unlock(&bdev->bd_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(bd_link_disk_holder);
-static void bd_unlink_disk_holder(struct block_device *bdev)
+/**
+ * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
+ * @bdev: the calimed slave bdev
+ * @disk: the holding disk
+ *
+ * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
- struct gendisk *disk = bdev->bd_holder_disk;
+ struct bd_holder_disk *holder;
- bdev->bd_holder_disk = NULL;
- if (!disk)
- return;
+ mutex_lock(&bdev->bd_mutex);
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- del_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
+ 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);
+ list_del_init(&holder->list);
+ kfree(holder);
+ }
+
+ mutex_unlock(&bdev->bd_mutex);
}
-#else
-static inline void bd_unlink_disk_holder(struct block_device *bdev)
-{ }
+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)
+static void flush_disk(struct block_device *bdev, bool kill_dirty)
{
- if (__invalidate_device(bdev)) {
+ if (__invalidate_device(bdev, kill_dirty)) {
char name[BDEVNAME_SIZE] = "";
if (bdev->bd_disk)
@@ -908,7 +973,7 @@ void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
"%s: detected capacity change from %lld to %lld\n",
name, bdev_size, disk_size);
i_size_write(bdev->bd_inode, disk_size);
- flush_disk(bdev);
+ flush_disk(bdev, false);
}
}
EXPORT_SYMBOL(check_disk_size_change);
@@ -961,7 +1026,7 @@ int check_disk_change(struct block_device *bdev)
if (!(events & DISK_EVENT_MEDIA_CHANGE))
return 0;
- flush_disk(bdev);
+ flush_disk(bdev, true);
if (bdops->revalidate_disk)
bdops->revalidate_disk(bdev->bd_disk);
return 1;
@@ -1157,12 +1222,6 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
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);
@@ -1240,6 +1299,11 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
if (err)
return ERR_PTR(err);
+ if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
+ blkdev_put(bdev, mode);
+ return ERR_PTR(-EACCES);
+ }
+
return bdev;
}
EXPORT_SYMBOL(blkdev_get_by_path);
@@ -1380,7 +1444,6 @@ int blkdev_put(struct block_device *bdev, fmode_t mode)
* unblock evpoll if it was a write holder.
*/
if (bdev_free) {
- bd_unlink_disk_holder(bdev);
if (bdev->bd_write_holder) {
disk_unblock_events(bdev->bd_disk);
bdev->bd_write_holder = false;
@@ -1544,7 +1607,7 @@ fail:
}
EXPORT_SYMBOL(lookup_bdev);
-int __invalidate_device(struct block_device *bdev)
+int __invalidate_device(struct block_device *bdev, bool kill_dirty)
{
struct super_block *sb = get_super(bdev);
int res = 0;
@@ -1557,7 +1620,7 @@ int __invalidate_device(struct block_device *bdev)
* hold).
*/
shrink_dcache_sb(sb);
- res = invalidate_inodes(sb);
+ res = invalidate_inodes(sb, kill_dirty);
drop_super(sb);
}
invalidate_bdev(bdev);
generated by cgit v1.2.3 (git 2.39.1) at 2025-10-29 05:23:24 +0000