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Diffstat (limited to 'block/bdev.c')
-rw-r--r--block/bdev.c84
1 files changed, 66 insertions, 18 deletions
diff --git a/block/bdev.c b/block/bdev.c
index 7a5f611c3d2e..b8e32d933a63 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -583,9 +583,6 @@ static void bd_finish_claiming(struct block_device *bdev, void *holder,
mutex_unlock(&bdev->bd_holder_lock);
bd_clear_claiming(whole, holder);
mutex_unlock(&bdev_lock);
-
- if (hops && hops->get_holder)
- hops->get_holder(holder);
}
/**
@@ -608,7 +605,6 @@ EXPORT_SYMBOL(bd_abort_claiming);
static void bd_end_claim(struct block_device *bdev, void *holder)
{
struct block_device *whole = bdev_whole(bdev);
- const struct blk_holder_ops *hops = bdev->bd_holder_ops;
bool unblock = false;
/*
@@ -631,9 +627,6 @@ static void bd_end_claim(struct block_device *bdev, void *holder)
whole->bd_holder = NULL;
mutex_unlock(&bdev_lock);
- if (hops && hops->put_holder)
- hops->put_holder(holder);
-
/*
* If this was the last claim, remove holder link and unblock evpoll if
* it was a write holder.
@@ -776,17 +769,17 @@ void blkdev_put_no_open(struct block_device *bdev)
static bool bdev_writes_blocked(struct block_device *bdev)
{
- return bdev->bd_writers == -1;
+ return bdev->bd_writers < 0;
}
static void bdev_block_writes(struct block_device *bdev)
{
- bdev->bd_writers = -1;
+ bdev->bd_writers--;
}
static void bdev_unblock_writes(struct block_device *bdev)
{
- bdev->bd_writers = 0;
+ bdev->bd_writers++;
}
static bool bdev_may_open(struct block_device *bdev, blk_mode_t mode)
@@ -813,6 +806,11 @@ static void bdev_claim_write_access(struct block_device *bdev, blk_mode_t mode)
bdev->bd_writers++;
}
+static inline bool bdev_unclaimed(const struct file *bdev_file)
+{
+ return bdev_file->private_data == BDEV_I(bdev_file->f_mapping->host);
+}
+
static void bdev_yield_write_access(struct file *bdev_file)
{
struct block_device *bdev;
@@ -820,14 +818,15 @@ static void bdev_yield_write_access(struct file *bdev_file)
if (bdev_allow_write_mounted)
return;
+ if (bdev_unclaimed(bdev_file))
+ return;
+
bdev = file_bdev(bdev_file);
- /* Yield exclusive or shared write access. */
- if (bdev_file->f_mode & FMODE_WRITE) {
- if (bdev_writes_blocked(bdev))
- bdev_unblock_writes(bdev);
- else
- bdev->bd_writers--;
- }
+
+ if (bdev_file->f_mode & FMODE_WRITE_RESTRICTED)
+ bdev_unblock_writes(bdev);
+ else if (bdev_file->f_mode & FMODE_WRITE)
+ bdev->bd_writers--;
}
/**
@@ -907,6 +906,8 @@ int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
bdev_file->f_mode |= FMODE_BUF_RASYNC | FMODE_CAN_ODIRECT;
if (bdev_nowait(bdev))
bdev_file->f_mode |= FMODE_NOWAIT;
+ if (mode & BLK_OPEN_RESTRICT_WRITES)
+ bdev_file->f_mode |= FMODE_WRITE_RESTRICTED;
bdev_file->f_mapping = bdev->bd_inode->i_mapping;
bdev_file->f_wb_err = filemap_sample_wb_err(bdev_file->f_mapping);
bdev_file->private_data = holder;
@@ -1012,6 +1013,20 @@ struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode,
}
EXPORT_SYMBOL(bdev_file_open_by_path);
+static inline void bd_yield_claim(struct file *bdev_file)
+{
+ struct block_device *bdev = file_bdev(bdev_file);
+ void *holder = bdev_file->private_data;
+
+ lockdep_assert_held(&bdev->bd_disk->open_mutex);
+
+ if (WARN_ON_ONCE(IS_ERR_OR_NULL(holder)))
+ return;
+
+ if (!bdev_unclaimed(bdev_file))
+ bd_end_claim(bdev, holder);
+}
+
void bdev_release(struct file *bdev_file)
{
struct block_device *bdev = file_bdev(bdev_file);
@@ -1036,7 +1051,7 @@ void bdev_release(struct file *bdev_file)
bdev_yield_write_access(bdev_file);
if (holder)
- bd_end_claim(bdev, holder);
+ bd_yield_claim(bdev_file);
/*
* Trigger event checking and tell drivers to flush MEDIA_CHANGE
@@ -1057,6 +1072,39 @@ put_no_open:
}
/**
+ * bdev_fput - yield claim to the block device and put the file
+ * @bdev_file: open block device
+ *
+ * Yield claim on the block device and put the file. Ensure that the
+ * block device can be reclaimed before the file is closed which is a
+ * deferred operation.
+ */
+void bdev_fput(struct file *bdev_file)
+{
+ if (WARN_ON_ONCE(bdev_file->f_op != &def_blk_fops))
+ return;
+
+ if (bdev_file->private_data) {
+ struct block_device *bdev = file_bdev(bdev_file);
+ struct gendisk *disk = bdev->bd_disk;
+
+ mutex_lock(&disk->open_mutex);
+ bdev_yield_write_access(bdev_file);
+ bd_yield_claim(bdev_file);
+ /*
+ * Tell release we already gave up our hold on the
+ * device and if write restrictions are available that
+ * we already gave up write access to the device.
+ */
+ bdev_file->private_data = BDEV_I(bdev_file->f_mapping->host);
+ mutex_unlock(&disk->open_mutex);
+ }
+
+ fput(bdev_file);
+}
+EXPORT_SYMBOL(bdev_fput);
+
+/**
* lookup_bdev() - Look up a struct block_device by name.
* @pathname: Name of the block device in the filesystem.
* @dev: Pointer to the block device's dev_t, if found.