Return AFS filesystem information through the filesystem info retrieval
system call. This includes the following:
(1) information about the capacity and resolution of the inode timestamps;
(2) the cell name as the domain name, setting FSINFO_DOMAIN_NAME;
(3) the volume name, setting FSINFO_VOLUME_NAME;
(4) the volume ID plus the volume type75 as the volume ID, setting
FSINFO_VOLUME_ID;
and unless AT_NO_ATTR_SYNC is specified:
(5) the statfs information retrieved from the server.
Note that no FSID value is returned as the local FSID since the FSID value
is a local handle used by NFSD; see the volume ID field instead.
Example output:
[root@andromeda ~]# ./test-fsinfo /afs
fsinfo(/afs) = 0
mask : 1ad
dev : 00:24
fs : type=6b414653 name=afs
ioc : 0
nameln: 255
flags : 1020
times : range=0-ffffffff
atime : gran=1s
btime : gran=1s
ctime : gran=1s
mtime : gran=1s
blocks: n=5000 fr=4998 av=4998
bsize : 1024
frsize: 1024
volid : 20000000 00000000 00000000 00000000
volume: 'root.afs'
domain: 'cambridge.redhat.com'
Possibly I should indicate the length of data stored in the volid field.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/afs/super.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 1fb4a5129f7d..ca88bb43ee1a 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_get_fsinfo(struct dentry *dentry, struct fsinfo *f,
+ unsigned flags);
struct file_system_type afs_fs_type = {
.owner = THIS_MODULE,
@@ -49,6 +51,7 @@ MODULE_ALIAS_FS("afs");
static const struct super_operations afs_super_ops = {
.statfs = afs_statfs,
+ .get_fsinfo = afs_get_fsinfo,
.alloc_inode = afs_alloc_inode,
.drop_inode = afs_drop_inode,
.destroy_inode = afs_destroy_inode,
@@ -555,3 +558,39 @@ static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
return 0;
}
+
+/*
+ * Read filesystem information.
+ */
+static int afs_get_fsinfo(struct dentry *dentry, struct fsinfo *f,
+ unsigned flags)
+{
+ struct afs_super_info *as = dentry->d_sb->s_fs_info;
+ int ret;
+
+ f->f_bsize = AFS_BLOCK_SIZE;
+ f->f_namelen = AFSNAMEMAX - 1;
+ f->f_min_time = 0;
+ f->f_max_time = U32_MAX;
+
+ /* Construct a volume ID from the AFS volume ID and type */
+ f->f_volume_id[0] = as->volume->vid >> 24;
+ f->f_volume_id[1] = as->volume->vid >> 16;
+ f->f_volume_id[2] = as->volume->vid >> 8;
+ f->f_volume_id[3] = as->volume->vid >> 0;
+ f->f_volume_id[4] = as->volume->type;
+
+ strcpy(f->f_volume_name, as->volume->vlocation->vldb.name);
+ strcpy(f->f_domain_name, as->volume->cell->name);
+
+ f->f_mask = FSINFO_VOLUME_ID | FSINFO_VOLUME_NAME | FSINFO_DOMAIN_NAME;
+
+ if (flags & AT_NO_ATTR_SYNC)
+ return 0;
+
+ ret = vfs_get_fsinfo_from_statfs(dentry, f, flags);
+
+ /* Don't pass the FSID to userspace since this isn't exportable */
+ f->f_mask &= ~FSINFO_FSID;
+ return 0;
+}
--
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