Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...

[linux-2.6.git] / drivers / md / dm.c

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index dfd0378..c99bf9f 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
  *
  * This file is released under the GPL.
  */
@@ -21,6 +21,8 @@
 #include <linux/hdreg.h>
 #include <linux/blktrace_api.h>
 
+#define DM_MSG_PREFIX "core"
+
 static const char *_name = DM_NAME;
 
 static unsigned int major = 0;
@@ -50,9 +52,9 @@ struct target_io {
 
 union map_info *dm_get_mapinfo(struct bio *bio)
 {
-        if (bio && bio->bi_private)
-                return &((struct target_io *)bio->bi_private)->info;
-        return NULL;
+       if (bio && bio->bi_private)
+               return &((struct target_io *)bio->bi_private)->info;
+       return NULL;
 }
 
 #define MINOR_ALLOCED ((void *)-1)
@@ -64,12 +66,14 @@ union map_info *dm_get_mapinfo(struct bio *bio)
 #define DMF_SUSPENDED 1
 #define DMF_FROZEN 2
 #define DMF_FREEING 3
+#define DMF_DELETING 4
 
 struct mapped_device {
        struct rw_semaphore io_lock;
        struct semaphore suspend_lock;
        rwlock_t map_lock;
        atomic_t holders;
+       atomic_t open_count;
 
        unsigned long flags;
 
@@ -163,7 +167,7 @@ static void local_exit(void)
        bioset_free(dm_set);
 
        if (unregister_blkdev(_major, _name) < 0)
-               DMERR("devfs_unregister_blkdev failed");
+               DMERR("unregister_blkdev failed");
 
        _major = 0;
 
@@ -228,12 +232,14 @@ static int dm_blk_open(struct inode *inode, struct file *file)
        if (!md)
                goto out;
 
-       if (test_bit(DMF_FREEING, &md->flags)) {
+       if (test_bit(DMF_FREEING, &md->flags) ||
+           test_bit(DMF_DELETING, &md->flags)) {
                md = NULL;
                goto out;
        }
 
        dm_get(md);
+       atomic_inc(&md->open_count);
 
 out:
        spin_unlock(&_minor_lock);
@@ -246,10 +252,35 @@ static int dm_blk_close(struct inode *inode, struct file *file)
        struct mapped_device *md;
 
        md = inode->i_bdev->bd_disk->private_data;
+       atomic_dec(&md->open_count);
        dm_put(md);
        return 0;
 }
 
+int dm_open_count(struct mapped_device *md)
+{
+       return atomic_read(&md->open_count);
+}
+
+/*
+ * Guarantees nothing is using the device before it's deleted.
+ */
+int dm_lock_for_deletion(struct mapped_device *md)
+{
+       int r = 0;
+
+       spin_lock(&_minor_lock);
+
+       if (dm_open_count(md))
+               r = -EBUSY;
+       else
+               set_bit(DMF_DELETING, &md->flags);
+
+       spin_unlock(&_minor_lock);
+
+       return r;
+}
+
 static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 {
        struct mapped_device *md = bdev->bd_disk->private_data;
@@ -474,8 +505,8 @@ static void __map_bio(struct dm_target *ti, struct bio *clone,
        if (r > 0) {
                /* the bio has been remapped so dispatch it */
 
-               blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone, 
-                                   tio->io->bio->bi_bdev->bd_dev, sector, 
+               blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone,
+                                   tio->io->bio->bi_bdev->bd_dev, sector,
                                    clone->bi_sector);
 
                generic_make_request(clone);
@@ -764,7 +795,7 @@ static int dm_any_congested(void *congested_data, int bdi_bits)
  *---------------------------------------------------------------*/
 static DEFINE_IDR(_minor_idr);
 
-static void free_minor(unsigned int minor)
+static void free_minor(int minor)
 {
        spin_lock(&_minor_lock);
        idr_remove(&_minor_idr, minor);
@@ -774,7 +805,7 @@ static void free_minor(unsigned int minor)
 /*
  * See if the device with a specific minor # is free.
  */
-static int specific_minor(struct mapped_device *md, unsigned int minor)
+static int specific_minor(struct mapped_device *md, int minor)
 {
        int r, m;
 
@@ -807,10 +838,9 @@ out:
        return r;
 }
 
-static int next_free_minor(struct mapped_device *md, unsigned int *minor)
+static int next_free_minor(struct mapped_device *md, int *minor)
 {
-       int r;
-       unsigned int m;
+       int r, m;
 
        r = idr_pre_get(&_minor_idr, GFP_KERNEL);
        if (!r)
@@ -841,7 +871,7 @@ static struct block_device_operations dm_blk_dops;
 /*
  * Allocate and initialise a blank device with a given minor.
  */
-static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
+static struct mapped_device *alloc_dev(int minor)
 {
        int r;
        struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL);
@@ -856,7 +886,10 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
                goto bad0;
 
        /* get a minor number for the dev */
-       r = persistent ? specific_minor(md, minor) : next_free_minor(md, &minor);
+       if (minor == DM_ANY_MINOR)
+               r = next_free_minor(md, &minor);
+       else
+               r = specific_minor(md, minor);
        if (r < 0)
                goto bad1;
 
@@ -865,6 +898,7 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
        init_MUTEX(&md->suspend_lock);
        rwlock_init(&md->map_lock);
        atomic_set(&md->holders, 1);
+       atomic_set(&md->open_count, 0);
        atomic_set(&md->event_nr, 0);
 
        md->queue = blk_alloc_queue(GFP_KERNEL);
@@ -929,7 +963,7 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
 
 static void free_dev(struct mapped_device *md)
 {
-       unsigned int minor = md->disk->first_minor;
+       int minor = md->disk->first_minor;
 
        if (md->suspended_bdev) {
                thaw_bdev(md->suspended_bdev, NULL);
@@ -1015,12 +1049,11 @@ static void __unbind(struct mapped_device *md)
 /*
  * Constructor for a new device.
  */
-static int create_aux(unsigned int minor, int persistent,
-                     struct mapped_device **result)
+int dm_create(int minor, struct mapped_device **result)
 {
        struct mapped_device *md;
 
-       md = alloc_dev(minor, persistent);
+       md = alloc_dev(minor);
        if (!md)
                return -ENXIO;
 
@@ -1028,16 +1061,6 @@ static int create_aux(unsigned int minor, int persistent,
        return 0;
 }
 
-int dm_create(struct mapped_device **result)
-{
-       return create_aux(0, 0, result);
-}
-
-int dm_create_with_minor(unsigned int minor, struct mapped_device **result)
-{
-       return create_aux(minor, 1, result);
-}
-
 static struct mapped_device *dm_find_md(dev_t dev)
 {
        struct mapped_device *md;
@@ -1051,7 +1074,7 @@ static struct mapped_device *dm_find_md(dev_t dev)
        md = idr_find(&_minor_idr, minor);
        if (md && (md == MINOR_ALLOCED ||
                   (dm_disk(md)->first_minor != minor) ||
-                  test_bit(DMF_FREEING, &md->flags))) {
+                  test_bit(DMF_FREEING, &md->flags))) {
                md = NULL;
                goto out;
        }
@@ -1087,6 +1110,12 @@ void dm_get(struct mapped_device *md)
        atomic_inc(&md->holders);
 }
 
+const char *dm_device_name(struct mapped_device *md)
+{
+       return md->name;
+}
+EXPORT_SYMBOL_GPL(dm_device_name);
+
 void dm_put(struct mapped_device *md)
 {
        struct dm_table *map;