[PATCH 10/14] afs: Implement show_options

From: David Howells
Date: Wed Jul 05 2017 - 11:25:47 EST


Implement the show_options superblock op for afs as part of a bid to get
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Also implement the show_devname op to display the correct device name and thus
avoid the need to display the cell= and volume= options.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
---

fs/afs/super.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/fs/afs/super.c b/fs/afs/super.c
index c79633e5cfd8..35d7e550b29c 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -37,6 +37,8 @@ static void afs_kill_super(struct super_block *sb);
static struct inode *afs_alloc_inode(struct super_block *sb);
static void afs_destroy_inode(struct inode *inode);
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int afs_show_devname(struct seq_file *m, struct dentry *root);
+static int afs_show_options(struct seq_file *m, struct dentry *root);

struct file_system_type afs_fs_type = {
.owner = THIS_MODULE,
@@ -53,7 +55,8 @@ static const struct super_operations afs_super_ops = {
.drop_inode = afs_drop_inode,
.destroy_inode = afs_destroy_inode,
.evict_inode = afs_evict_inode,
- .show_options = generic_show_options,
+ .show_devname = afs_show_devname,
+ .show_options = afs_show_options,
};

static struct kmem_cache *afs_inode_cachep;
@@ -136,6 +139,45 @@ void __exit afs_fs_exit(void)
}

/*
+ * Display the mount device name in /proc/mounts.
+ */
+static int afs_show_devname(struct seq_file *m, struct dentry *root)
+{
+ struct afs_super_info *as = root->d_sb->s_fs_info;
+ struct afs_volume *volume = as->volume;
+ struct afs_cell *cell = volume->cell;
+ const char *suf = "";
+ char pref = '%';
+
+ switch (volume->type) {
+ case AFSVL_RWVOL:
+ break;
+ case AFSVL_ROVOL:
+ pref = '#';
+ if (volume->type_force)
+ suf = ".readonly";
+ break;
+ case AFSVL_BACKVOL:
+ pref = '#';
+ suf = ".backup";
+ break;
+ }
+
+ seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->vlocation->vldb.name, suf);
+ return 0;
+}
+
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int afs_show_options(struct seq_file *m, struct dentry *root)
+{
+ if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
+ seq_puts(m, "autocell");
+ return 0;
+}
+
+/*
* parse the mount options
* - this function has been shamelessly adapted from the ext3 fs which
* shamelessly adapted it from the msdos fs
@@ -426,7 +468,6 @@ static struct dentry *afs_mount(struct file_system_type *fs_type,
deactivate_locked_super(sb);
goto error;
}
- save_mount_options(sb, new_opts);
sb->s_flags |= MS_ACTIVE;
} else {
_debug("reuse");