From: Ingo Molnar <[email protected]>
teach special (recursive) locking code to the lock validator. Has no
effect on non-lockdep kernels.
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Arjan van de Ven <[email protected]>
---
drivers/md/md.c | 6 +--
fs/block_dev.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++-------
include/linux/fs.h | 17 ++++++++
3 files changed, 112 insertions(+), 16 deletions(-)
Index: linux/drivers/md/md.c
===================================================================
--- linux.orig/drivers/md/md.c
+++ linux/drivers/md/md.c
@@ -1394,7 +1394,7 @@ static int lock_rdev(mdk_rdev_t *rdev, d
struct block_device *bdev;
char b[BDEVNAME_SIZE];
- bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
+ bdev = open_partition_by_devnum(dev, FMODE_READ|FMODE_WRITE);
if (IS_ERR(bdev)) {
printk(KERN_ERR "md: could not open %s.\n",
__bdevname(dev, b));
@@ -1404,7 +1404,7 @@ static int lock_rdev(mdk_rdev_t *rdev, d
if (err) {
printk(KERN_ERR "md: could not bd_claim %s.\n",
bdevname(bdev, b));
- blkdev_put(bdev);
+ blkdev_put_partition(bdev);
return err;
}
rdev->bdev = bdev;
@@ -1418,7 +1418,7 @@ static void unlock_rdev(mdk_rdev_t *rdev
if (!bdev)
MD_BUG();
bd_release(bdev);
- blkdev_put(bdev);
+ blkdev_put_partition(bdev);
}
void md_autodetect_dev(dev_t dev);
Index: linux/fs/block_dev.c
===================================================================
--- linux.orig/fs/block_dev.c
+++ linux/fs/block_dev.c
@@ -746,7 +746,7 @@ static int bd_claim_by_kobject(struct bl
if (!bo)
return -ENOMEM;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
res = bd_claim(bdev, holder);
if (res || !add_bd_holder(bdev, bo))
free_bd_holder(bo);
@@ -771,7 +771,7 @@ static void bd_release_from_kobject(stru
if (!kobj)
return;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
bd_release(bdev);
if ((bo = del_bd_holder(bdev, kobj)))
free_bd_holder(bo);
@@ -829,6 +829,22 @@ struct block_device *open_by_devnum(dev_
EXPORT_SYMBOL(open_by_devnum);
+static int
+blkdev_get_partition(struct block_device *bdev, mode_t mode, unsigned flags);
+
+struct block_device *open_partition_by_devnum(dev_t dev, unsigned mode)
+{
+ struct block_device *bdev = bdget(dev);
+ int err = -ENOMEM;
+ int flags = mode & FMODE_WRITE ? O_RDWR : O_RDONLY;
+ if (bdev)
+ err = blkdev_get_partition(bdev, mode, flags);
+ return err ? ERR_PTR(err) : bdev;
+}
+
+EXPORT_SYMBOL(open_partition_by_devnum);
+
+
/*
* This routine checks whether a removable media has been changed,
* and invalidates all buffer-cache-entries in that case. This
@@ -875,7 +891,11 @@ void bd_set_size(struct block_device *bd
}
EXPORT_SYMBOL(bd_set_size);
-static int do_open(struct block_device *bdev, struct file *file)
+static int
+blkdev_get_whole(struct block_device *bdev, mode_t mode, unsigned flags);
+
+static int
+do_open(struct block_device *bdev, struct file *file, unsigned int subtype)
{
struct module *owner = NULL;
struct gendisk *disk;
@@ -892,7 +912,8 @@ static int do_open(struct block_device *
}
owner = disk->fops->owner;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, subtype);
+
if (!bdev->bd_openers) {
bdev->bd_disk = disk;
bdev->bd_contains = bdev;
@@ -917,13 +938,17 @@ static int do_open(struct block_device *
struct block_device *whole;
whole = bdget_disk(disk, 0);
ret = -ENOMEM;
+ /*
+ * We must not recurse deeper than 1:
+ */
+ WARN_ON(subtype != 0);
if (!whole)
goto out_first;
- ret = blkdev_get(whole, file->f_mode, file->f_flags);
+ ret = blkdev_get_whole(whole, file->f_mode, file->f_flags);
if (ret)
goto out_first;
bdev->bd_contains = whole;
- mutex_lock(&whole->bd_mutex);
+ mutex_lock_nested(&whole->bd_mutex, BD_MUTEX_WHOLE);
whole->bd_part_count++;
p = disk->part[part - 1];
bdev->bd_inode->i_data.backing_dev_info =
@@ -951,7 +976,8 @@ static int do_open(struct block_device *
if (bdev->bd_invalidated)
rescan_partitions(bdev->bd_disk, bdev);
} else {
- mutex_lock(&bdev->bd_contains->bd_mutex);
+ mutex_lock_nested(&bdev->bd_contains->bd_mutex,
+ BD_MUTEX_PARTITION);
bdev->bd_contains->bd_part_count++;
mutex_unlock(&bdev->bd_contains->bd_mutex);
}
@@ -992,11 +1018,49 @@ int blkdev_get(struct block_device *bdev
fake_file.f_dentry = &fake_dentry;
fake_dentry.d_inode = bdev->bd_inode;
- return do_open(bdev, &fake_file);
+ return do_open(bdev, &fake_file, BD_MUTEX_NORMAL);
}
EXPORT_SYMBOL(blkdev_get);
+static int
+blkdev_get_whole(struct block_device *bdev, mode_t mode, unsigned flags)
+{
+ /*
+ * This crockload is due to bad choice of ->open() type.
+ * It will go away.
+ * For now, block device ->open() routine must _not_
+ * examine anything in 'inode' argument except ->i_rdev.
+ */
+ struct file fake_file = {};
+ struct dentry fake_dentry = {};
+ fake_file.f_mode = mode;
+ fake_file.f_flags = flags;
+ fake_file.f_dentry = &fake_dentry;
+ fake_dentry.d_inode = bdev->bd_inode;
+
+ return do_open(bdev, &fake_file, BD_MUTEX_WHOLE);
+}
+
+static int
+blkdev_get_partition(struct block_device *bdev, mode_t mode, unsigned flags)
+{
+ /*
+ * This crockload is due to bad choice of ->open() type.
+ * It will go away.
+ * For now, block device ->open() routine must _not_
+ * examine anything in 'inode' argument except ->i_rdev.
+ */
+ struct file fake_file = {};
+ struct dentry fake_dentry = {};
+ fake_file.f_mode = mode;
+ fake_file.f_flags = flags;
+ fake_file.f_dentry = &fake_dentry;
+ fake_dentry.d_inode = bdev->bd_inode;
+
+ return do_open(bdev, &fake_file, BD_MUTEX_PARTITION);
+}
+
static int blkdev_open(struct inode * inode, struct file * filp)
{
struct block_device *bdev;
@@ -1012,7 +1076,7 @@ static int blkdev_open(struct inode * in
bdev = bd_acquire(inode);
- res = do_open(bdev, filp);
+ res = do_open(bdev, filp, BD_MUTEX_NORMAL);
if (res)
return res;
@@ -1026,13 +1090,13 @@ static int blkdev_open(struct inode * in
return res;
}
-int blkdev_put(struct block_device *bdev)
+static int __blkdev_put(struct block_device *bdev, unsigned int subtype)
{
int ret = 0;
struct inode *bd_inode = bdev->bd_inode;
struct gendisk *disk = bdev->bd_disk;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, subtype);
lock_kernel();
if (!--bdev->bd_openers) {
sync_blockdev(bdev);
@@ -1042,7 +1106,9 @@ int blkdev_put(struct block_device *bdev
if (disk->fops->release)
ret = disk->fops->release(bd_inode, NULL);
} else {
- mutex_lock(&bdev->bd_contains->bd_mutex);
+ WARN_ON(subtype != 0);
+ mutex_lock_nested(&bdev->bd_contains->bd_mutex,
+ BD_MUTEX_PARTITION);
bdev->bd_contains->bd_part_count--;
mutex_unlock(&bdev->bd_contains->bd_mutex);
}
@@ -1059,7 +1125,8 @@ int blkdev_put(struct block_device *bdev
bdev->bd_disk = NULL;
bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
if (bdev != bdev->bd_contains) {
- blkdev_put(bdev->bd_contains);
+ WARN_ON(subtype != 0);
+ __blkdev_put(bdev->bd_contains, 1);
}
bdev->bd_contains = NULL;
}
@@ -1069,8 +1136,20 @@ int blkdev_put(struct block_device *bdev
return ret;
}
+int blkdev_put(struct block_device *bdev)
+{
+ return __blkdev_put(bdev, BD_MUTEX_NORMAL);
+}
+
EXPORT_SYMBOL(blkdev_put);
+int blkdev_put_partition(struct block_device *bdev)
+{
+ return __blkdev_put(bdev, BD_MUTEX_PARTITION);
+}
+
+EXPORT_SYMBOL(blkdev_put_partition);
+
static int blkdev_close(struct inode * inode, struct file * filp)
{
struct block_device *bdev = I_BDEV(filp->f_mapping->host);
Index: linux/include/linux/fs.h
===================================================================
--- linux.orig/include/linux/fs.h
+++ linux/include/linux/fs.h
@@ -436,6 +436,21 @@ struct block_device {
};
/*
+ * bdev->bd_mutex nesting types for the LOCKDEP validator:
+ *
+ * 0: normal
+ * 1: 'whole'
+ * 2: 'partition'
+ */
+enum bdev_bd_mutex_lock_type
+{
+ BD_MUTEX_NORMAL,
+ BD_MUTEX_WHOLE,
+ BD_MUTEX_PARTITION
+};
+
+
+/*
* Radix-tree tags, for tagging dirty and writeback pages within the pagecache
* radix trees
*/
@@ -1404,6 +1419,7 @@ extern void bd_set_size(struct block_dev
extern void bd_forget(struct inode *inode);
extern void bdput(struct block_device *);
extern struct block_device *open_by_devnum(dev_t, unsigned);
+extern struct block_device *open_partition_by_devnum(dev_t, unsigned);
extern const struct file_operations def_blk_fops;
extern const struct address_space_operations def_blk_aops;
extern const struct file_operations def_chr_fops;
@@ -1414,6 +1430,7 @@ extern int blkdev_ioctl(struct inode *,
extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
extern int blkdev_get(struct block_device *, mode_t, unsigned);
extern int blkdev_put(struct block_device *);
+extern int blkdev_put_partition(struct block_device *);
extern int bd_claim(struct block_device *, void *);
extern void bd_release(struct block_device *);
#ifdef CONFIG_SYSFS
-
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