Commit 9591c3a3 authored by Amir Goldstein's avatar Amir Goldstein Committed by Jan Kara
Browse files

fs: introduce a wrapper uuid_to_fsid() 

Some filesystem's use a digest of their uuid for f_fsid.
Create a simple wrapper for this open coded folding.

Filesystems that have a non null uuid but use the block device
number for f_fsid may also consider using this helper.

[JK: Added missing asm/byteorder.h include]
Link: https://lore.kernel.org/r/20210322173944.449469-2-amir73il@gmail.com


Acked-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 22d483b9

fs/ext2/super.c

+1 −4
Original line number Diff line number Diff line
@@ -1399,7 +1399,6 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 
	struct super_block *sb = dentry->d_sb;

	struct ext2_sb_info *sbi = EXT2_SB(sb);

	struct ext2_super_block *es = sbi->s_es;

	u64 fsid;



	spin_lock(&sbi->s_lock);
@@ -1453,9 +1452,7 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) 
	buf->f_ffree = ext2_count_free_inodes(sb);

	es->s_free_inodes_count = cpu_to_le32(buf->f_ffree);

	buf->f_namelen = EXT2_NAME_LEN;

	fsid = le64_to_cpup((void *)es->s_uuid) ^

	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));

	buf->f_fsid = u64_to_fsid(fsid);

	buf->f_fsid = uuid_to_fsid(es->s_uuid);

	spin_unlock(&sbi->s_lock);

	return 0;

}

fs/ext4/super.c

+1 −4
Original line number Diff line number Diff line
@@ -6148,7 +6148,6 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf) 
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct ext4_super_block *es = sbi->s_es;

	ext4_fsblk_t overhead = 0, resv_blocks;

	u64 fsid;

	s64 bfree;

	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
@@ -6169,9 +6168,7 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf) 
	buf->f_files = le32_to_cpu(es->s_inodes_count);

	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);

	buf->f_namelen = EXT4_NAME_LEN;

	fsid = le64_to_cpup((void *)es->s_uuid) ^

	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));

	buf->f_fsid = u64_to_fsid(fsid);

	buf->f_fsid = uuid_to_fsid(es->s_uuid);



#ifdef CONFIG_QUOTA

	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&

fs/zonefs/super.c

+1 −4
Original line number Diff line number Diff line
@@ -1104,7 +1104,6 @@ static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf) 
	struct super_block *sb = dentry->d_sb;

	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);

	enum zonefs_ztype t;

	u64 fsid;



	buf->f_type = ZONEFS_MAGIC;

	buf->f_bsize = sb->s_blocksize;
@@ -1127,9 +1126,7 @@ static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf) 


	spin_unlock(&sbi->s_lock);



	fsid = le64_to_cpup((void *)sbi->s_uuid.b) ^

		le64_to_cpup((void *)sbi->s_uuid.b + sizeof(u64));

	buf->f_fsid = u64_to_fsid(fsid);

	buf->f_fsid = uuid_to_fsid(sbi->s_uuid.b);



	return 0;

}

include/linux/statfs.h

+8 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 


#include <linux/types.h>

#include <asm/statfs.h>

#include <asm/byteorder.h>



struct kstatfs {

	long f_type;
@@ -50,4 +51,11 @@ static inline __kernel_fsid_t u64_to_fsid(u64 v) 
	return (__kernel_fsid_t){.val = {(u32)v, (u32)(v>>32)}};

}



/* Fold 16 bytes uuid to 64 bit fsid */

static inline __kernel_fsid_t uuid_to_fsid(__u8 *uuid)

{

	return u64_to_fsid(le64_to_cpup((void *)uuid) ^

		le64_to_cpup((void *)(uuid + sizeof(u64))));

}



#endif