Some code in btrfs_scan_one_device will be re-used by the other function later,
so restructure btrfs_scan_one_device and pick up those code to make a new
function.
Signed-off-by: Miao Xie <mi...@cn.fujitsu.com>
---
fs/btrfs/volumes.c | 57 +++++++++++++++++++++++++++++++-----------------------
1 file changed, 33 insertions(+), 24 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 740a4f9..bcb19d5 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -885,24 +885,18 @@ int btrfs_open_devices(struct btrfs_fs_devices
*fs_devices,
return ret;
}
-/*
- * Look for a btrfs signature on a device. This may be called out of the mount
path
- * and we are not allowed to call set_blocksize during the scan. The superblock
- * is read via pagecache
- */
-int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
- struct btrfs_fs_devices **fs_devices_ret)
+static int __scan_device(struct block_device *bdev, const char *path,
+ struct btrfs_fs_devices **fs_devices_ret)
{
struct btrfs_super_block *disk_super;
- struct block_device *bdev;
struct page *page;
void *p;
- int ret = -EINVAL;
u64 devid;
u64 transid;
u64 total_devices;
u64 bytenr;
pgoff_t index;
+ int ret;
/*
* we would like to check all the supers, but that would make
@@ -911,38 +905,30 @@ int btrfs_scan_one_device(const char *path, fmode_t
flags, void *holder,
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
bytenr = btrfs_sb_offset(0);
- flags |= FMODE_EXCL;
- mutex_lock(&uuid_mutex);
-
- bdev = blkdev_get_by_path(path, flags, holder);
-
- if (IS_ERR(bdev)) {
- ret = PTR_ERR(bdev);
- goto error;
- }
/* make sure our super fits in the device */
if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
- goto error_bdev_put;
+ return -EINVAL;
/* make sure our super fits in the page */
if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
- goto error_bdev_put;
+ return -EINVAL;
/* make sure our super doesn't straddle pages on disk */
index = bytenr >> PAGE_CACHE_SHIFT;
if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
- goto error_bdev_put;
+ return -EINVAL;
/* pull in the page with our super */
page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
index, GFP_NOFS);
if (IS_ERR_OR_NULL(page))
- goto error_bdev_put;
+ return -ENOMEM;
- p = kmap(page);
+ ret = -EINVAL;
+ p = kmap(page);
/* align our pointer to the offset of the super block */
disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
@@ -974,7 +960,30 @@ error_unmap:
kunmap(page);
page_cache_release(page);
-error_bdev_put:
+ return ret;
+}
+
+/*
+ * Look for a btrfs signature on a device. This may be called out of the mount
path
+ * and we are not allowed to call set_blocksize during the scan. The superblock
+ * is read via pagecache
+ */
+int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
+ struct btrfs_fs_devices **fs_devices_ret)
+{
+ struct block_device *bdev;
+ int ret;
+
+ flags |= FMODE_EXCL;
+
+ mutex_lock(&uuid_mutex);
+ bdev = blkdev_get_by_path(path, flags, holder);
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ goto error;
+ }
+
+ ret = __scan_device(bdev, path, fs_devices_ret);
blkdev_put(bdev, flags);
error:
mutex_unlock(&uuid_mutex);
--
1.9.3
--
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