vfs: new superblock methods to override /proc/*/mount{s,info}

a) ->show_devname(m, mnt) - what to put into devname columns in mounts,
mountinfo and mountstats
b) ->show_path(m, mnt) - what to put into relative path column in mountinfo

Leaving those NULL gives old behaviour.  NFS switched to using those.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2011-03-16 06:59:40 -04:00
parent f8ad9c4bae
commit c7f404b40a
3 changed files with 60 additions and 9 deletions

View File

@@ -263,6 +263,8 @@ static match_table_t nfs_local_lock_tokens = {
static void nfs_umount_begin(struct super_block *);
static int nfs_statfs(struct dentry *, struct kstatfs *);
static int nfs_show_options(struct seq_file *, struct vfsmount *);
static int nfs_show_devname(struct seq_file *, struct vfsmount *);
static int nfs_show_path(struct seq_file *, struct vfsmount *);
static int nfs_show_stats(struct seq_file *, struct vfsmount *);
static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
@@ -296,6 +298,8 @@ static const struct super_operations nfs_sops = {
.evict_inode = nfs_evict_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_devname = nfs_show_devname,
.show_path = nfs_show_path,
.show_stats = nfs_show_stats,
.remount_fs = nfs_remount,
};
@@ -366,6 +370,8 @@ static const struct super_operations nfs4_sops = {
.evict_inode = nfs4_evict_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_devname = nfs_show_devname,
.show_path = nfs_show_path,
.show_stats = nfs_show_stats,
.remount_fs = nfs_remount,
};
@@ -726,6 +732,28 @@ static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
return 0;
}
static int nfs_show_devname(struct seq_file *m, struct vfsmount *mnt)
{
char *page = (char *) __get_free_page(GFP_KERNEL);
char *devname, *dummy;
int err = 0;
if (!page)
return -ENOMEM;
devname = nfs_path(&dummy, mnt->mnt_root, page, PAGE_SIZE);
if (IS_ERR(devname))
err = PTR_ERR(devname);
else
seq_escape(m, devname, " \t\n\\");
free_page((unsigned long)page);
return err;
}
static int nfs_show_path(struct seq_file *m, struct vfsmount *mnt)
{
seq_puts(m, "/");
return 0;
}
/*
* Present statistical information for this VFS mountpoint
*/