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Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c95
1 files changed, 61 insertions, 34 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 930b9fc..0e48151 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -55,6 +55,7 @@ union map_info *dm_get_mapinfo(struct bio *bio)
*/
#define DMF_BLOCK_IO 0
#define DMF_SUSPENDED 1
+#define DMF_FROZEN 2
struct mapped_device {
struct rw_semaphore io_lock;
@@ -97,7 +98,7 @@ struct mapped_device {
* freeze/thaw support require holding onto a super block
*/
struct super_block *frozen_sb;
- struct block_device *frozen_bdev;
+ struct block_device *suspended_bdev;
};
#define MIN_IOS 256
@@ -836,9 +837,9 @@ static void __set_size(struct mapped_device *md, sector_t size)
{
set_capacity(md->disk, size);
- down(&md->frozen_bdev->bd_inode->i_sem);
- i_size_write(md->frozen_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
- up(&md->frozen_bdev->bd_inode->i_sem);
+ down(&md->suspended_bdev->bd_inode->i_sem);
+ i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+ up(&md->suspended_bdev->bd_inode->i_sem);
}
static int __bind(struct mapped_device *md, struct dm_table *t)
@@ -902,10 +903,9 @@ int dm_create_with_minor(unsigned int minor, struct mapped_device **result)
return create_aux(minor, 1, result);
}
-void *dm_get_mdptr(dev_t dev)
+static struct mapped_device *dm_find_md(dev_t dev)
{
struct mapped_device *md;
- void *mdptr = NULL;
unsigned minor = MINOR(dev);
if (MAJOR(dev) != _major || minor >= (1 << MINORBITS))
@@ -914,12 +914,32 @@ void *dm_get_mdptr(dev_t dev)
down(&_minor_lock);
md = idr_find(&_minor_idr, minor);
-
- if (md && (dm_disk(md)->first_minor == minor))
- mdptr = md->interface_ptr;
+ if (!md || (dm_disk(md)->first_minor != minor))
+ md = NULL;
up(&_minor_lock);
+ return md;
+}
+
+struct mapped_device *dm_get_md(dev_t dev)
+{
+ struct mapped_device *md = dm_find_md(dev);
+
+ if (md)
+ dm_get(md);
+
+ return md;
+}
+
+void *dm_get_mdptr(dev_t dev)
+{
+ struct mapped_device *md;
+ void *mdptr = NULL;
+
+ md = dm_find_md(dev);
+ if (md)
+ mdptr = md->interface_ptr;
return mdptr;
}
@@ -991,43 +1011,33 @@ out:
*/
static int lock_fs(struct mapped_device *md)
{
- int r = -ENOMEM;
-
- md->frozen_bdev = bdget_disk(md->disk, 0);
- if (!md->frozen_bdev) {
- DMWARN("bdget failed in lock_fs");
- goto out;
- }
+ int r;
WARN_ON(md->frozen_sb);
- md->frozen_sb = freeze_bdev(md->frozen_bdev);
+ md->frozen_sb = freeze_bdev(md->suspended_bdev);
if (IS_ERR(md->frozen_sb)) {
r = PTR_ERR(md->frozen_sb);
- goto out_bdput;
+ md->frozen_sb = NULL;
+ return r;
}
+ set_bit(DMF_FROZEN, &md->flags);
+
/* don't bdput right now, we don't want the bdev
- * to go away while it is locked. We'll bdput
- * in unlock_fs
+ * to go away while it is locked.
*/
return 0;
-
-out_bdput:
- bdput(md->frozen_bdev);
- md->frozen_sb = NULL;
- md->frozen_bdev = NULL;
-out:
- return r;
}
static void unlock_fs(struct mapped_device *md)
{
- thaw_bdev(md->frozen_bdev, md->frozen_sb);
- bdput(md->frozen_bdev);
+ if (!test_bit(DMF_FROZEN, &md->flags))
+ return;
+ thaw_bdev(md->suspended_bdev, md->frozen_sb);
md->frozen_sb = NULL;
- md->frozen_bdev = NULL;
+ clear_bit(DMF_FROZEN, &md->flags);
}
/*
@@ -1037,7 +1047,7 @@ static void unlock_fs(struct mapped_device *md)
* dm_bind_table, dm_suspend must be called to flush any in
* flight bios and ensure that any further io gets deferred.
*/
-int dm_suspend(struct mapped_device *md)
+int dm_suspend(struct mapped_device *md, int do_lockfs)
{
struct dm_table *map = NULL;
DECLARE_WAITQUEUE(wait, current);
@@ -1053,10 +1063,19 @@ int dm_suspend(struct mapped_device *md)
/* This does not get reverted if there's an error later. */
dm_table_presuspend_targets(map);
- /* Flush I/O to the device. */
- r = lock_fs(md);
- if (r)
+ md->suspended_bdev = bdget_disk(md->disk, 0);
+ if (!md->suspended_bdev) {
+ DMWARN("bdget failed in dm_suspend");
+ r = -ENOMEM;
goto out;
+ }
+
+ /* Flush I/O to the device. */
+ if (do_lockfs) {
+ r = lock_fs(md);
+ if (r)
+ goto out;
+ }
/*
* First we set the BLOCK_IO flag so no more ios will be mapped.
@@ -1105,6 +1124,11 @@ int dm_suspend(struct mapped_device *md)
r = 0;
out:
+ if (r && md->suspended_bdev) {
+ bdput(md->suspended_bdev);
+ md->suspended_bdev = NULL;
+ }
+
dm_table_put(map);
up(&md->suspend_lock);
return r;
@@ -1135,6 +1159,9 @@ int dm_resume(struct mapped_device *md)
unlock_fs(md);
+ bdput(md->suspended_bdev);
+ md->suspended_bdev = NULL;
+
clear_bit(DMF_SUSPENDED, &md->flags);
dm_table_unplug_all(map);
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