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-rw-r--r--fs/block_dev.c175
1 files changed, 85 insertions, 90 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 8ae833e00443..6b9d19ffa5af 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -103,6 +103,35 @@ void invalidate_bdev(struct block_device *bdev)
}
EXPORT_SYMBOL(invalidate_bdev);
+/*
+ * Drop all buffers & page cache for given bdev range. This function bails
+ * with error if bdev has other exclusive owner (such as filesystem).
+ */
+int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
+ loff_t lstart, loff_t lend)
+{
+ struct block_device *claimed_bdev = NULL;
+ int err;
+
+ /*
+ * If we don't hold exclusive handle for the device, upgrade to it
+ * while we discard the buffer cache to avoid discarding buffers
+ * under live filesystem.
+ */
+ if (!(mode & FMODE_EXCL)) {
+ claimed_bdev = bdev->bd_contains;
+ err = bd_prepare_to_claim(bdev, claimed_bdev,
+ truncate_bdev_range);
+ if (err)
+ return err;
+ }
+ truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend);
+ if (claimed_bdev)
+ bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range);
+ return 0;
+}
+EXPORT_SYMBOL(truncate_bdev_range);
+
static void set_init_blocksize(struct block_device *bdev)
{
bdev->bd_inode->i_blkbits = blksize_bits(bdev_logical_block_size(bdev));
@@ -876,11 +905,11 @@ struct block_device *bdget(dev_t dev)
bdev = &BDEV_I(inode)->bdev;
if (inode->i_state & I_NEW) {
+ spin_lock_init(&bdev->bd_size_lock);
bdev->bd_contains = NULL;
bdev->bd_super = NULL;
bdev->bd_inode = inode;
bdev->bd_part_count = 0;
- bdev->bd_invalidated = 0;
inode->i_mode = S_IFBLK;
inode->i_rdev = dev;
inode->i_bdev = bdev;
@@ -1290,6 +1319,7 @@ static void check_disk_size_change(struct gendisk *disk,
{
loff_t disk_size, bdev_size;
+ spin_lock(&bdev->bd_size_lock);
disk_size = (loff_t)get_capacity(disk) << 9;
bdev_size = i_size_read(bdev->bd_inode);
if (disk_size != bdev_size) {
@@ -1299,85 +1329,51 @@ static void check_disk_size_change(struct gendisk *disk,
disk->disk_name, bdev_size, disk_size);
}
i_size_write(bdev->bd_inode, disk_size);
- if (bdev_size > disk_size && __invalidate_device(bdev, false))
+ }
+ spin_unlock(&bdev->bd_size_lock);
+
+ if (bdev_size > disk_size) {
+ if (__invalidate_device(bdev, false))
pr_warn("VFS: busy inodes on resized disk %s\n",
disk->disk_name);
}
- bdev->bd_invalidated = 0;
}
/**
- * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
- * @disk: struct gendisk to be revalidated
+ * revalidate_disk_size - checks for disk size change and adjusts bdev size.
+ * @disk: struct gendisk to check
+ * @verbose: if %true log a message about a size change if there is any
*
- * This routine is a wrapper for lower-level driver's revalidate_disk
- * call-backs. It is used to do common pre and post operations needed
- * for all revalidate_disk operations.
+ * This routine checks to see if the bdev size does not match the disk size
+ * and adjusts it if it differs. When shrinking the bdev size, its all caches
+ * are freed.
*/
-int revalidate_disk(struct gendisk *disk)
+void revalidate_disk_size(struct gendisk *disk, bool verbose)
{
- int ret = 0;
-
- if (disk->fops->revalidate_disk)
- ret = disk->fops->revalidate_disk(disk);
+ struct block_device *bdev;
/*
* Hidden disks don't have associated bdev so there's no point in
- * revalidating it.
+ * revalidating them.
*/
- if (!(disk->flags & GENHD_FL_HIDDEN)) {
- struct block_device *bdev = bdget_disk(disk, 0);
-
- if (!bdev)
- return ret;
+ if (disk->flags & GENHD_FL_HIDDEN)
+ return;
- mutex_lock(&bdev->bd_mutex);
- check_disk_size_change(disk, bdev, ret == 0);
- mutex_unlock(&bdev->bd_mutex);
+ bdev = bdget_disk(disk, 0);
+ if (bdev) {
+ check_disk_size_change(disk, bdev, verbose);
bdput(bdev);
}
- return ret;
}
-EXPORT_SYMBOL(revalidate_disk);
+EXPORT_SYMBOL(revalidate_disk_size);
-/*
- * This routine checks whether a removable media has been changed,
- * and invalidates all buffer-cache-entries in that case. This
- * is a relatively slow routine, so we have to try to minimize using
- * it. Thus it is called only upon a 'mount' or 'open'. This
- * is the best way of combining speed and utility, I think.
- * People changing diskettes in the middle of an operation deserve
- * to lose :-)
- */
-int check_disk_change(struct block_device *bdev)
+void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors)
{
- struct gendisk *disk = bdev->bd_disk;
- const struct block_device_operations *bdops = disk->fops;
- unsigned int events;
-
- events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE |
- DISK_EVENT_EJECT_REQUEST);
- if (!(events & DISK_EVENT_MEDIA_CHANGE))
- return 0;
-
- if (__invalidate_device(bdev, true))
- pr_warn("VFS: busy inodes on changed media %s\n",
- disk->disk_name);
- bdev->bd_invalidated = 1;
- if (bdops->revalidate_disk)
- bdops->revalidate_disk(bdev->bd_disk);
- return 1;
-}
-
-EXPORT_SYMBOL(check_disk_change);
-
-void bd_set_size(struct block_device *bdev, loff_t size)
-{
- inode_lock(bdev->bd_inode);
- i_size_write(bdev->bd_inode, size);
- inode_unlock(bdev->bd_inode);
+ spin_lock(&bdev->bd_size_lock);
+ i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
+ spin_unlock(&bdev->bd_size_lock);
}
-EXPORT_SYMBOL(bd_set_size);
+EXPORT_SYMBOL(bd_set_nr_sectors);
static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
@@ -1388,6 +1384,8 @@ int bdev_disk_changed(struct block_device *bdev, bool invalidate)
lockdep_assert_held(&bdev->bd_mutex);
+ clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
+
rescan:
ret = blk_drop_partitions(bdev);
if (ret)
@@ -1446,22 +1444,8 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
struct gendisk *disk;
int ret;
int partno;
- int perm = 0;
bool first_open = false, unblock_events = true, need_restart;
- if (mode & FMODE_READ)
- perm |= MAY_READ;
- if (mode & FMODE_WRITE)
- perm |= MAY_WRITE;
- /*
- * hooks: /n/, see "layering violations".
- */
- if (!for_part) {
- ret = devcgroup_inode_permission(bdev->bd_inode, perm);
- if (ret != 0)
- return ret;
- }
-
restart:
need_restart = false;
ret = -ENXIO;
@@ -1514,7 +1498,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
}
if (!ret) {
- bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
+ bd_set_nr_sectors(bdev, get_capacity(disk));
set_init_blocksize(bdev);
}
@@ -1524,7 +1508,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
* The latter is necessary to prevent ghost
* partitions on a removed medium.
*/
- if (bdev->bd_invalidated &&
+ if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
(!ret || ret == -ENOMEDIUM))
bdev_disk_changed(bdev, ret == -ENOMEDIUM);
@@ -1542,7 +1526,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
ret = -ENXIO;
goto out_clear;
}
- bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
+ bd_set_nr_sectors(bdev, bdev->bd_part->nr_sects);
set_init_blocksize(bdev);
}
@@ -1554,7 +1538,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
if (bdev->bd_disk->fops->open)
ret = bdev->bd_disk->fops->open(bdev, mode);
/* the same as first opener case, read comment there */
- if (bdev->bd_invalidated &&
+ if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
(!ret || ret == -ENOMEDIUM))
bdev_disk_changed(bdev, ret == -ENOMEDIUM);
if (ret)
@@ -1632,16 +1616,27 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
* RETURNS:
* 0 on success, -errno on failure.
*/
-int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
+static int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
{
- int res;
+ int ret, perm = 0;
- res =__blkdev_get(bdev, mode, holder, 0);
- if (res)
- bdput(bdev);
- return res;
+ if (mode & FMODE_READ)
+ perm |= MAY_READ;
+ if (mode & FMODE_WRITE)
+ perm |= MAY_WRITE;
+ ret = devcgroup_inode_permission(bdev->bd_inode, perm);
+ if (ret)
+ goto bdput;
+
+ ret =__blkdev_get(bdev, mode, holder, 0);
+ if (ret)
+ goto bdput;
+ return 0;
+
+bdput:
+ bdput(bdev);
+ return ret;
}
-EXPORT_SYMBOL(blkdev_get);
/**
* blkdev_get_by_path - open a block device by name
@@ -1889,7 +1884,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
if (bdev_read_only(I_BDEV(bd_inode)))
return -EPERM;
- if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode))
+ if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
return -ETXTBSY;
if (!iov_iter_count(from))
@@ -1969,7 +1964,6 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
loff_t len)
{
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
- struct address_space *mapping;
loff_t end = start + len - 1;
loff_t isize;
int error;
@@ -1997,8 +1991,9 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
return -EINVAL;
/* Invalidate the page cache, including dirty pages. */
- mapping = bdev->bd_inode->i_mapping;
- truncate_inode_pages_range(mapping, start, end);
+ error = truncate_bdev_range(bdev, file->f_mode, start, end);
+ if (error)
+ return error;
switch (mode) {
case FALLOC_FL_ZERO_RANGE:
@@ -2025,7 +2020,7 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
* the caller will be given -EBUSY. The third argument is
* inclusive, so the rounding here is safe.
*/
- return invalidate_inode_pages2_range(mapping,
+ return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping,
start >> PAGE_SHIFT,
end >> PAGE_SHIFT);
}