[PATCH] dm: move idr_pre_get

idr_pre_get() can sleep while allocating memory.

The next patch will change _minor_lock into a spinlock, so this patch moves
idr_pre_get() outside the lock in preparation.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 14 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 87d8ca1121e2..6e577e749329 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -766,6 +766,10 @@ static int specific_minor(struct mapped_device *md, unsigned int minor)
         if (minor >= (1 << MINORBITS))
                 return -EINVAL;
 
+        r = idr_pre_get(&_minor_idr, GFP_KERNEL);
+        if (!r)
+                return -ENOMEM;
+
         mutex_lock(&_minor_lock);
 
         if (idr_find(&_minor_idr, minor)) {
@@ -773,16 +777,9 @@ static int specific_minor(struct mapped_device *md, unsigned int minor)
                 goto out;
         }
 
-        r = idr_pre_get(&_minor_idr, GFP_KERNEL);
-        if (!r) {
-                r = -ENOMEM;
-                goto out;
-        }
-
         r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m);
-        if (r) {
+        if (r)
                 goto out;
-        }
 
         if (m != minor) {
                 idr_remove(&_minor_idr, m);
@@ -800,13 +797,11 @@ static int next_free_minor(struct mapped_device *md, unsigned int *minor)
         int r;
         unsigned int m;
 
-        mutex_lock(&_minor_lock);
-
         r = idr_pre_get(&_minor_idr, GFP_KERNEL);
-        if (!r) {
-                r = -ENOMEM;
-                goto out;
-        }
+        if (!r)
+                return -ENOMEM;
+
+        mutex_lock(&_minor_lock);
 
         r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m);
         if (r) {