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authorChuck Lever <cel@netapp.com>2006-03-20 21:44:12 +0300
committerTrond Myklebust <Trond.Myklebust@netapp.com>2006-03-20 21:44:12 +0300
commitb4629fe2f094b719847f31be1ee5ab38300038b2 (patch)
tree158b3aabf291ef9462e3e02493fb4c45265f9e8e /fs/namespace.c
parent1356b8c28d67cafd74f7e7dcfb39bf53681790a5 (diff)
downloadlinux-b4629fe2f094b719847f31be1ee5ab38300038b2.tar.xz
VFS: New /proc file /proc/self/mountstats
Create a new file under /proc/self, called mountstats, where mounted file systems can export information (configuration options, performance counters, and so on). Use a mechanism similar to /proc/mounts and s_ops->show_options. This mechanism does not violate namespace security, and is safe to use while other processes are unmounting file systems. Thanks to Mike Waychison for his review and comments. Test-plan: Test concurrent mount/unmount operations while cat'ing /proc/self/mountstats. Signed-off-by: Chuck Lever <cel@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/namespace.c')
-rw-r--r--fs/namespace.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 39c81a8d6316..71e75bcf4d28 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -399,6 +399,44 @@ struct seq_operations mounts_op = {
.show = show_vfsmnt
};
+static int show_vfsstat(struct seq_file *m, void *v)
+{
+ struct vfsmount *mnt = v;
+ int err = 0;
+
+ /* device */
+ if (mnt->mnt_devname) {
+ seq_puts(m, "device ");
+ mangle(m, mnt->mnt_devname);
+ } else
+ seq_puts(m, "no device");
+
+ /* mount point */
+ seq_puts(m, " mounted on ");
+ seq_path(m, mnt, mnt->mnt_root, " \t\n\\");
+ seq_putc(m, ' ');
+
+ /* file system type */
+ seq_puts(m, "with fstype ");
+ mangle(m, mnt->mnt_sb->s_type->name);
+
+ /* optional statistics */
+ if (mnt->mnt_sb->s_op->show_stats) {
+ seq_putc(m, ' ');
+ err = mnt->mnt_sb->s_op->show_stats(m, mnt);
+ }
+
+ seq_putc(m, '\n');
+ return err;
+}
+
+struct seq_operations mountstats_op = {
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = show_vfsstat,
+};
+
/**
* may_umount_tree - check if a mount tree is busy
* @mnt: root of mount tree