From cdb4c5748cb3ac533889a6b0b95aa10651e68785 Mon Sep 17 00:00:00 2001 From: Zach Brown Date: Wed, 20 Feb 2013 00:55:13 +0000 Subject: [PATCH] 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: Zach Brown Signed-off-by: Josef Bacik --- fs/btrfs/check-integrity.c | 3 +-- fs/btrfs/ctree.h | 2 +- fs/btrfs/disk-io.c | 6 ++---- fs/btrfs/volumes.c | 3 +-- 4 files changed, 5 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c index 11d47bfb62b4..18af6f48781a 100644 --- a/fs/btrfs/check-integrity.c +++ b/fs/btrfs/check-integrity.c @@ -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 || diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 961ff2986341..1679051f4d39 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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 diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index e511d9f78c19..39ff34a62a24 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -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; } diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 567076542d1d..72b1cf1b2b5e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -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); -- 2.30.2