Commit eb705421 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: update the cached overhead value in the superblock 



If we (re-)calculate the file system overhead amount and it's
different from the on-disk s_overhead_clusters value, update the
on-disk version since this can take potentially quite a while on
bigalloc file systems.

Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
parent 85d825db

fs/ext4/ext4.h

+1 −0
Original line number Diff line number Diff line
@@ -3068,6 +3068,7 @@ int ext4_fileattr_set(struct user_namespace *mnt_userns, 
		      struct dentry *dentry, struct fileattr *fa);

int ext4_fileattr_get(struct dentry *dentry, struct fileattr *fa);

extern void ext4_reset_inode_seed(struct inode *inode);

int ext4_update_overhead(struct super_block *sb);



/* migrate.c */

extern int ext4_ext_migrate(struct inode *);

fs/ext4/ioctl.c

+16 −0
Original line number Diff line number Diff line
@@ -1652,3 +1652,19 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));

}

#endif



static void set_overhead(struct ext4_super_block *es, const void *arg)

{

	es->s_overhead_clusters = cpu_to_le32(*((unsigned long *) arg));

}



int ext4_update_overhead(struct super_block *sb)

{

	struct ext4_sb_info *sbi = EXT4_SB(sb);



	if (sb_rdonly(sb) || sbi->s_overhead == 0 ||

	    sbi->s_overhead == le32_to_cpu(sbi->s_es->s_overhead_clusters))

		return 0;



	return ext4_update_superblocks_fn(sb, set_overhead, &sbi->s_overhead);

}

fs/ext4/super.c

+2 −0
Original line number Diff line number Diff line
@@ -5618,6 +5618,8 @@ static int ext4_fill_super(struct super_block *sb, struct fs_context *fc) 
		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "

			 "Quota mode: %s.", descr, ext4_quota_mode(sb));



	/* Update the s_overhead_clusters if necessary */

	ext4_update_overhead(sb);

	return 0;



free_sbi: