#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/major.h>
-#include <linux/smp_lock.h>
#include <linux/device_cgroup.h>
#include <linux/highmem.h>
#include <linux/blkdev.h>
{
return &BDEV_I(inode)->bdev;
}
-
EXPORT_SYMBOL(I_BDEV);
/*
- * move the inode from it's current bdi to the a new bdi. if the inode is dirty
- * we need to move it onto the dirty list of @dst so that the inode is always
- * on the right list.
+ * Move the inode from its current bdi to a new bdi. If the inode is dirty we
+ * need to move it onto the dirty list of @dst so that the inode is always on
+ * the right list.
*/
static void bdev_inode_switch_bdi(struct inode *inode,
struct backing_dev_info *dst)
{
- spin_lock(&inode_lock);
+ struct backing_dev_info *old = inode->i_data.backing_dev_info;
+
+ if (unlikely(dst == old)) /* deadlock avoidance */
+ return;
+ bdi_lock_two(&old->wb, &dst->wb);
+ spin_lock(&inode->i_lock);
inode->i_data.backing_dev_info = dst;
if (inode->i_state & I_DIRTY)
list_move(&inode->i_wb_list, &dst->wb.b_dirty);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&old->wb.list_lock);
+ spin_unlock(&dst->wb.list_lock);
}
static sector_t max_block(struct block_device *bdev)
mutex_lock(&bd_inode->i_mutex);
size = i_size_read(bd_inode);
+ retval = -EINVAL;
switch (origin) {
- case 2:
+ case SEEK_END:
offset += size;
break;
- case 1:
+ case SEEK_CUR:
offset += file->f_pos;
+ case SEEK_SET:
+ break;
+ default:
+ goto out;
}
- retval = -EINVAL;
if (offset >= 0 && offset <= size) {
if (offset != file->f_pos) {
file->f_pos = offset;
}
retval = offset;
}
+out:
mutex_unlock(&bd_inode->i_mutex);
return retval;
}
-int blkdev_fsync(struct file *filp, int datasync)
+int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
{
struct inode *bd_inode = filp->f_mapping->host;
struct block_device *bdev = I_BDEV(bd_inode);
int error;
+
+ error = filemap_write_and_wait_range(filp->f_mapping, start, end);
+ if (error)
+ return error;
/*
* There is no need to serialise calls to blkdev_issue_flush with
* i_mutex and doing so causes performance issues with concurrent
* O_SYNC writers to a block device.
*/
- mutex_unlock(&bd_inode->i_mutex);
-
error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL);
if (error == -EOPNOTSUPP)
error = 0;
- mutex_lock(&bd_inode->i_mutex);
-
return error;
}
EXPORT_SYMBOL(blkdev_fsync);
return &ei->vfs_inode;
}
-static void bdev_destroy_inode(struct inode *inode)
+static void bdev_i_callback(struct rcu_head *head)
{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
struct bdev_inode *bdi = BDEV_I(inode);
+ INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(bdev_cachep, bdi);
}
+static void bdev_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, bdev_i_callback);
+}
+
static void init_once(void *foo)
{
struct bdev_inode *ei = (struct bdev_inode *) foo;
mutex_init(&bdev->bd_mutex);
INIT_LIST_HEAD(&bdev->bd_inodes);
INIT_LIST_HEAD(&bdev->bd_list);
+#ifdef CONFIG_SYSFS
+ INIT_LIST_HEAD(&bdev->bd_holder_disks);
+#endif
inode_init_once(&ei->vfs_inode);
/* Initialize mutex for freeze. */
mutex_init(&bdev->bd_fsfreeze_mutex);
static struct dentry *bd_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- return mount_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576);
+ return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, 0x62646576);
}
static struct file_system_type bd_type = {
if (inode->i_state & I_NEW) {
bdev->bd_contains = NULL;
+ bdev->bd_super = NULL;
bdev->bd_inode = inode;
bdev->bd_block_size = (1 << inode->i_blkbits);
bdev->bd_part_count = 0;
* @whole: whole block device containing @bdev, may equal @bdev
* @holder: holder trying to claim @bdev
*
- * Test whther @bdev can be claimed by @holder.
+ * Test whether @bdev can be claimed by @holder.
*
* CONTEXT:
* spin_lock(&bdev_lock).
if (!disk)
return ERR_PTR(-ENXIO);
- whole = bdget_disk(disk, 0);
+ /*
+ * Normally, @bdev should equal what's returned from bdget_disk()
+ * if partno is 0; however, some drivers (floppy) use multiple
+ * bdev's for the same physical device and @bdev may be one of the
+ * aliases. Keep @bdev if partno is 0. This means claimer
+ * tracking is broken for those devices but it has always been that
+ * way.
+ */
+ if (partno)
+ whole = bdget_disk(disk, 0);
+ else
+ whole = bdgrab(bdev);
+
module_put(disk->fops->owner);
put_disk(disk);
if (!whole)
}
#ifdef CONFIG_SYSFS
+struct bd_holder_disk {
+ struct list_head list;
+ struct gendisk *disk;
+ int refcnt;
+};
+
+static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
+ struct gendisk *disk)
+{
+ struct bd_holder_disk *holder;
+
+ list_for_each_entry(holder, &bdev->bd_holder_disks, list)
+ if (holder->disk == disk)
+ return holder;
+ return NULL;
+}
+
static int add_symlink(struct kobject *from, struct kobject *to)
{
return sysfs_create_link(from, to, kobject_name(to));
* @bdev: the claimed slave bdev
* @disk: the holding disk
*
+ * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
+ *
* This functions creates the following sysfs symlinks.
*
* - from "slaves" directory of the holder @disk to the claimed @bdev
*/
int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
+ struct bd_holder_disk *holder;
int ret = 0;
mutex_lock(&bdev->bd_mutex);
- WARN_ON_ONCE(!bdev->bd_holder || bdev->bd_holder_disk);
+ WARN_ON_ONCE(!bdev->bd_holder);
/* FIXME: remove the following once add_disk() handles errors */
if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
goto out_unlock;
- ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- if (ret)
+ holder = bd_find_holder_disk(bdev, disk);
+ if (holder) {
+ holder->refcnt++;
goto out_unlock;
+ }
- ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
- if (ret) {
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ holder = kzalloc(sizeof(*holder), GFP_KERNEL);
+ if (!holder) {
+ ret = -ENOMEM;
goto out_unlock;
}
- bdev->bd_holder_disk = disk;
+ INIT_LIST_HEAD(&holder->list);
+ holder->disk = disk;
+ holder->refcnt = 1;
+
+ ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ if (ret)
+ goto out_free;
+
+ ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
+ if (ret)
+ goto out_del;
+ /*
+ * bdev could be deleted beneath us which would implicitly destroy
+ * the holder directory. Hold on to it.
+ */
+ kobject_get(bdev->bd_part->holder_dir);
+
+ list_add(&holder->list, &bdev->bd_holder_disks);
+ goto out_unlock;
+
+out_del:
+ del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+out_free:
+ kfree(holder);
out_unlock:
mutex_unlock(&bdev->bd_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(bd_link_disk_holder);
-static void bd_unlink_disk_holder(struct block_device *bdev)
+/**
+ * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
+ * @bdev: the calimed slave bdev
+ * @disk: the holding disk
+ *
+ * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
{
- struct gendisk *disk = bdev->bd_holder_disk;
+ struct bd_holder_disk *holder;
- bdev->bd_holder_disk = NULL;
- if (!disk)
- return;
+ mutex_lock(&bdev->bd_mutex);
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- del_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
+ holder = bd_find_holder_disk(bdev, disk);
+
+ if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
+ del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
+ del_symlink(bdev->bd_part->holder_dir,
+ &disk_to_dev(disk)->kobj);
+ kobject_put(bdev->bd_part->holder_dir);
+ list_del_init(&holder->list);
+ kfree(holder);
+ }
+
+ mutex_unlock(&bdev->bd_mutex);
}
-#else
-static inline void bd_unlink_disk_holder(struct block_device *bdev)
-{ }
+EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
#endif
/**
* flush_disk - invalidates all buffer-cache entries on a disk
*
* @bdev: struct block device to be flushed
+ * @kill_dirty: flag to guide handling of dirty inodes
*
* Invalidates all buffer-cache entries on a disk. It should be called
* when a disk has been changed -- either by a media change or online
* resize.
*/
-static void flush_disk(struct block_device *bdev)
+static void flush_disk(struct block_device *bdev, bool kill_dirty)
{
- if (__invalidate_device(bdev)) {
+ if (__invalidate_device(bdev, kill_dirty)) {
char name[BDEVNAME_SIZE] = "";
if (bdev->bd_disk)
"%s: detected capacity change from %lld to %lld\n",
name, bdev_size, disk_size);
i_size_write(bdev->bd_inode, disk_size);
- flush_disk(bdev);
+ flush_disk(bdev, false);
}
}
EXPORT_SYMBOL(check_disk_size_change);
if (!(events & DISK_EVENT_MEDIA_CHANGE))
return 0;
- flush_disk(bdev);
+ flush_disk(bdev, true);
if (bdops->revalidate_disk)
bdops->revalidate_disk(bdev->bd_disk);
return 1;
if (!disk)
goto out;
+ disk_block_events(disk);
mutex_lock_nested(&bdev->bd_mutex, for_part);
if (!bdev->bd_openers) {
bdev->bd_disk = disk;
if (!bdev->bd_part)
goto out_clear;
+ ret = 0;
if (disk->fops->open) {
ret = disk->fops->open(bdev, mode);
if (ret == -ERESTARTSYS) {
*/
disk_put_part(bdev->bd_part);
bdev->bd_part = NULL;
- module_put(disk->fops->owner);
- put_disk(disk);
bdev->bd_disk = NULL;
mutex_unlock(&bdev->bd_mutex);
+ disk_unblock_events(disk);
+ module_put(disk->fops->owner);
+ put_disk(disk);
goto restart;
}
- if (ret)
- goto out_clear;
}
- if (!bdev->bd_openers) {
+
+ if (!ret && !bdev->bd_openers) {
bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
bdi = blk_get_backing_dev_info(bdev);
if (bdi == NULL)
bdi = &default_backing_dev_info;
bdev_inode_switch_bdi(bdev->bd_inode, bdi);
}
- if (bdev->bd_invalidated)
+
+ /*
+ * If the device is invalidated, rescan partition
+ * if open succeeded or failed with -ENOMEDIUM.
+ * The latter is necessary to prevent ghost
+ * partitions on a removed medium.
+ */
+ if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM))
rescan_partitions(disk, bdev);
+ if (ret)
+ goto out_clear;
} else {
struct block_device *whole;
whole = bdget_disk(disk, 0);
bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
}
} else {
- module_put(disk->fops->owner);
- put_disk(disk);
- disk = NULL;
if (bdev->bd_contains == bdev) {
- if (bdev->bd_disk->fops->open) {
+ ret = 0;
+ if (bdev->bd_disk->fops->open)
ret = bdev->bd_disk->fops->open(bdev, mode);
- if (ret)
- goto out_unlock_bdev;
- }
- if (bdev->bd_invalidated)
+ /* the same as first opener case, read comment there */
+ if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM))
rescan_partitions(bdev->bd_disk, bdev);
+ if (ret)
+ goto out_unlock_bdev;
}
+ /* only one opener holds refs to the module and disk */
+ module_put(disk->fops->owner);
+ put_disk(disk);
}
bdev->bd_openers++;
if (for_part)
bdev->bd_part_count++;
mutex_unlock(&bdev->bd_mutex);
+ disk_unblock_events(disk);
return 0;
out_clear:
bdev->bd_contains = NULL;
out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
- out:
- if (disk)
- module_put(disk->fops->owner);
+ disk_unblock_events(disk);
+ module_put(disk->fops->owner);
put_disk(disk);
+ out:
bdput(bdev);
return ret;
res = __blkdev_get(bdev, mode, 0);
- /* __blkdev_get() may alter read only status, check it afterwards */
- if (!res && (mode & FMODE_WRITE) && bdev_read_only(bdev)) {
- __blkdev_put(bdev, mode, 0);
- res = -EACCES;
- }
-
if (whole) {
+ struct gendisk *disk = whole->bd_disk;
+
/* finish claiming */
mutex_lock(&bdev->bd_mutex);
spin_lock(&bdev_lock);
spin_unlock(&bdev_lock);
/*
- * Block event polling for write claims. Any write
- * holder makes the write_holder state stick until all
- * are released. This is good enough and tracking
- * individual writeable reference is too fragile given
- * the way @mode is used in blkdev_get/put().
+ * Block event polling for write claims if requested. Any
+ * write holder makes the write_holder state stick until
+ * all are released. This is good enough and tracking
+ * individual writeable reference is too fragile given the
+ * way @mode is used in blkdev_get/put().
*/
- if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
+ if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
+ (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
bdev->bd_write_holder = true;
- disk_block_events(bdev->bd_disk);
+ disk_block_events(disk);
}
mutex_unlock(&bdev->bd_mutex);
if (err)
return ERR_PTR(err);
+ if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
+ blkdev_put(bdev, mode);
+ return ERR_PTR(-EACCES);
+ }
+
return bdev;
}
EXPORT_SYMBOL(blkdev_get_by_path);
int blkdev_put(struct block_device *bdev, fmode_t mode)
{
+ mutex_lock(&bdev->bd_mutex);
+
if (mode & FMODE_EXCL) {
bool bdev_free;
* are protected with bdev_lock. bd_mutex is to
* synchronize disk_holder unlinking.
*/
- mutex_lock(&bdev->bd_mutex);
spin_lock(&bdev_lock);
WARN_ON_ONCE(--bdev->bd_holders < 0);
* If this was the last claim, remove holder link and
* unblock evpoll if it was a write holder.
*/
- if (bdev_free) {
- bd_unlink_disk_holder(bdev);
- if (bdev->bd_write_holder) {
- disk_unblock_events(bdev->bd_disk);
- bdev->bd_write_holder = false;
- } else
- disk_check_events(bdev->bd_disk);
+ if (bdev_free && bdev->bd_write_holder) {
+ disk_unblock_events(bdev->bd_disk);
+ bdev->bd_write_holder = false;
}
+ }
- mutex_unlock(&bdev->bd_mutex);
- } else
- disk_check_events(bdev->bd_disk);
+ /*
+ * Trigger event checking and tell drivers to flush MEDIA_CHANGE
+ * event. This is to ensure detection of media removal commanded
+ * from userland - e.g. eject(1).
+ */
+ disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE);
+
+ mutex_unlock(&bdev->bd_mutex);
return __blkdev_put(bdev, mode, 0);
}
static const struct address_space_operations def_blk_aops = {
.readpage = blkdev_readpage,
.writepage = blkdev_writepage,
- .sync_page = block_sync_page,
.write_begin = blkdev_write_begin,
.write_end = blkdev_write_end,
.writepages = generic_writepages,
}
EXPORT_SYMBOL(lookup_bdev);
-int __invalidate_device(struct block_device *bdev)
+int __invalidate_device(struct block_device *bdev, bool kill_dirty)
{
struct super_block *sb = get_super(bdev);
int res = 0;
* hold).
*/
shrink_dcache_sb(sb);
- res = invalidate_inodes(sb);
+ res = invalidate_inodes(sb, kill_dirty);
drop_super(sb);
}
invalidate_bdev(bdev);
Code Review / linux-2.6.git / blobdiff