Commit cdb4c574 authored by Zach Brown's avatar Zach Brown Committed by Josef Bacik
Browse files

btrfs: define BTRFS_MAGIC as a u64 value 



super.magic is an le64 but it's treated as an unterminated string when
compared against BTRFS_MAGIC which is defined as a string.  Instead
define BTRFS_MAGIC as a normal hex value and use endian helpers to
compare it to the super's magic.

I tested this by mounting an fs made before the change and made sure
that it didn't introduce sparse errors.  This matches a similar cleanup
that is pending in btrfs-progs.  David Sterba pointed out that we should
fix the kernel side as well :).

Signed-off-by: default avatarZach Brown <zab@redhat.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent a8bfd4ab

fs/btrfs/check-integrity.c

+1 −2
Original line number Diff line number Diff line
@@ -813,8 +813,7 @@ static int btrfsic_process_superblock_dev_mirror( 
	    (bh->b_data + (dev_bytenr & 4095));



	if (btrfs_super_bytenr(super_tmp) != dev_bytenr ||

	    strncmp((char *)(&(super_tmp->magic)), BTRFS_MAGIC,

		    sizeof(super_tmp->magic)) ||

	    super_tmp->magic != cpu_to_le64(BTRFS_MAGIC) ||

	    memcmp(device->uuid, super_tmp->dev_item.uuid, BTRFS_UUID_SIZE) ||

	    btrfs_super_nodesize(super_tmp) != state->metablock_size ||

	    btrfs_super_leafsize(super_tmp) != state->metablock_size ||

fs/btrfs/ctree.h

+1 −1
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ extern struct kmem_cache *btrfs_path_cachep; 
extern struct kmem_cache *btrfs_free_space_cachep;

struct btrfs_ordered_sum;



#define BTRFS_MAGIC "_BHRfS_M"

#define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */



#define BTRFS_MAX_MIRRORS 3

fs/btrfs/disk-io.c

+2 −4
Original line number Diff line number Diff line
@@ -2407,8 +2407,7 @@ int open_ctree(struct super_block *sb, 
	sb->s_blocksize = sectorsize;

	sb->s_blocksize_bits = blksize_bits(sectorsize);



	if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,

		    sizeof(disk_super->magic))) {

	if (disk_super->magic != cpu_to_le64(BTRFS_MAGIC)) {

		printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);

		goto fail_sb_buffer;

	}
@@ -2815,8 +2814,7 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev) 


		super = (struct btrfs_super_block *)bh->b_data;

		if (btrfs_super_bytenr(super) != bytenr ||

		    strncmp((char *)(&super->magic), BTRFS_MAGIC,

			    sizeof(super->magic))) {

		    super->magic != cpu_to_le64(BTRFS_MAGIC)) {

			brelse(bh);

			continue;

		}

fs/btrfs/volumes.c

+1 −2
Original line number Diff line number Diff line
@@ -855,8 +855,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, 
	disk_super = p + (bytenr & ~PAGE_CACHE_MASK);



	if (btrfs_super_bytenr(disk_super) != bytenr ||

	    strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,

		    sizeof(disk_super->magic)))

	    disk_super->magic != cpu_to_le64(BTRFS_MAGIC))

		goto error_unmap;



	devid = btrfs_stack_device_id(&disk_super->dev_item);

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