(for review comments pls).
btrfs_scan_one_device() needs SB, instead of doing it from scratch could
use btrfs_get_bdev_and_sb()
Signed-off-by: Anand Jain <Anand.Jain@xxxxxxxxxx>
---
fs/btrfs/volumes.c | 51 ++++++---------------------------------------------
1 file changed, 6 insertions(+), 45 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c166355..94e6131 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1053,14 +1053,11 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
{
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;
+ struct buffer_head *bh;
/*
* we would like to check all the supers, but that would make
@@ -1068,44 +1065,12 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
* So, we need to add a special mount option to scan for
* later supers, using BTRFS_SUPER_MIRROR_MAX instead
*/
- bytenr = btrfs_sb_offset(0);
mutex_lock(&uuid_mutex);
- bdev = blkdev_get_by_path(path, flags, holder);
-
- if (IS_ERR(bdev)) {
- ret = PTR_ERR(bdev);
+ ret = btrfs_get_bdev_and_sb(path, flags, holder, 0, &bdev, &bh);
+ if (ret)
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;
-
- /* make sure our super fits in the page */
- if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
- goto error_bdev_put;
-
- /* 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;
-
- /* 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;
-
- p = kmap(page);
-
- /* align our pointer to the offset of the super block */
- disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
-
- if (btrfs_super_bytenr(disk_super) != bytenr ||
- btrfs_super_magic(disk_super) != BTRFS_MAGIC)
- goto error_unmap;
+ disk_super = (struct btrfs_super_block *) bh->b_data;
devid = btrfs_stack_device_id(&disk_super->dev_item);
transid = btrfs_super_generation(disk_super);
@@ -1125,13 +1090,9 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
}
-
-error_unmap:
- kunmap(page);
- page_cache_release(page);
-
-error_bdev_put:
+ brelse(bh);
blkdev_put(bdev, flags);
+
error:
mutex_unlock(&uuid_mutex);
return ret;
--
2.0.0.257.g75cc6c6
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