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author | Chuck Lever <cel@netapp.com> | 2006-03-20 13:44:12 -0500 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-03-20 13:44:12 -0500 |
commit | b4629fe2f094b719847f31be1ee5ab38300038b2 (patch) | |
tree | 158b3aabf291ef9462e3e02493fb4c45265f9e8e /fs/namespace.c | |
parent | 1356b8c28d67cafd74f7e7dcfb39bf53681790a5 (diff) | |
download | kernel_samsung_smdk4412-b4629fe2f094b719847f31be1ee5ab38300038b2.zip kernel_samsung_smdk4412-b4629fe2f094b719847f31be1ee5ab38300038b2.tar.gz kernel_samsung_smdk4412-b4629fe2f094b719847f31be1ee5ab38300038b2.tar.bz2 |
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.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 39c81a8..71e75bc 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 |