diff options
author | Ram Pai <linuxram@us.ibm.com> | 2008-03-27 12:06:25 (GMT) |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-04-23 04:05:03 (GMT) |
commit | 2d4d4864ac08caff5c204a752bd004eed4f08760 (patch) | |
tree | a8907c33afae589146fdcd06eacd740aff48c6a1 /fs/namespace.c | |
parent | a1a2c409b666befc58c2db9c7fbddf200f153470 (diff) | |
download | linux-2d4d4864ac08caff5c204a752bd004eed4f08760.tar.xz |
[patch 6/7] vfs: mountinfo: add /proc/<pid>/mountinfo
[mszeredi@suse.cz] rewrite and split big patch into managable chunks
/proc/mounts in its current form lacks important information:
- propagation state
- root of mount for bind mounts
- the st_dev value used within the filesystem
- identifier for each mount and it's parent
It also suffers from the following problems:
- not easily extendable
- ambiguity of mountpoints within a chrooted environment
- doesn't distinguish between filesystem dependent and independent options
- doesn't distinguish between per mount and per super block options
This patch introduces /proc/<pid>/mountinfo which attempts to address
all these deficiencies.
Code shared between /proc/<pid>/mounts and /proc/<pid>/mountinfo is
extracted into separate functions.
Thanks to Al Viro for the help in getting the design right.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namespace.c')
-rw-r--r-- | fs/namespace.c | 119 |
1 files changed, 96 insertions, 23 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index dfdf51e..c807b8d 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -746,20 +746,30 @@ static void m_stop(struct seq_file *m, void *v) up_read(&namespace_sem); } -static int show_vfsmnt(struct seq_file *m, void *v) +struct proc_fs_info { + int flag; + const char *str; +}; + +static void show_sb_opts(struct seq_file *m, struct super_block *sb) { - struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); - int err = 0; - static struct proc_fs_info { - int flag; - char *str; - } fs_info[] = { + static const struct proc_fs_info fs_info[] = { { MS_SYNCHRONOUS, ",sync" }, { MS_DIRSYNC, ",dirsync" }, { MS_MANDLOCK, ",mand" }, { 0, NULL } }; - static struct proc_fs_info mnt_info[] = { + const struct proc_fs_info *fs_infop; + + for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { + if (sb->s_flags & fs_infop->flag) + seq_puts(m, fs_infop->str); + } +} + +static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt) +{ + static const struct proc_fs_info mnt_info[] = { { MNT_NOSUID, ",nosuid" }, { MNT_NODEV, ",nodev" }, { MNT_NOEXEC, ",noexec" }, @@ -768,27 +778,37 @@ static int show_vfsmnt(struct seq_file *m, void *v) { MNT_RELATIME, ",relatime" }, { 0, NULL } }; - struct proc_fs_info *fs_infop; + const struct proc_fs_info *fs_infop; + + for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) { + if (mnt->mnt_flags & fs_infop->flag) + seq_puts(m, fs_infop->str); + } +} + +static void show_type(struct seq_file *m, struct super_block *sb) +{ + mangle(m, sb->s_type->name); + if (sb->s_subtype && sb->s_subtype[0]) { + seq_putc(m, '.'); + mangle(m, sb->s_subtype); + } +} + +static int show_vfsmnt(struct seq_file *m, void *v) +{ + struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); + int err = 0; struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt }; mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none"); seq_putc(m, ' '); seq_path(m, &mnt_path, " \t\n\\"); seq_putc(m, ' '); - mangle(m, mnt->mnt_sb->s_type->name); - if (mnt->mnt_sb->s_subtype && mnt->mnt_sb->s_subtype[0]) { - seq_putc(m, '.'); - mangle(m, mnt->mnt_sb->s_subtype); - } + show_type(m, mnt->mnt_sb); seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw"); - for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { - if (mnt->mnt_sb->s_flags & fs_infop->flag) - seq_puts(m, fs_infop->str); - } - for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) { - if (mnt->mnt_flags & fs_infop->flag) - seq_puts(m, fs_infop->str); - } + show_sb_opts(m, mnt->mnt_sb); + show_mnt_opts(m, mnt); if (mnt->mnt_sb->s_op->show_options) err = mnt->mnt_sb->s_op->show_options(m, mnt); seq_puts(m, " 0 0\n"); @@ -802,6 +822,59 @@ const struct seq_operations mounts_op = { .show = show_vfsmnt }; +static int show_mountinfo(struct seq_file *m, void *v) +{ + struct proc_mounts *p = m->private; + struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); + struct super_block *sb = mnt->mnt_sb; + struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt }; + struct path root = p->root; + int err = 0; + + seq_printf(m, "%i %i %u:%u ", mnt->mnt_id, mnt->mnt_parent->mnt_id, + MAJOR(sb->s_dev), MINOR(sb->s_dev)); + seq_dentry(m, mnt->mnt_root, " \t\n\\"); + seq_putc(m, ' '); + seq_path_root(m, &mnt_path, &root, " \t\n\\"); + if (root.mnt != p->root.mnt || root.dentry != p->root.dentry) { + /* + * Mountpoint is outside root, discard that one. Ugly, + * but less so than trying to do that in iterator in a + * race-free way (due to renames). + */ + return SEQ_SKIP; + } + seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw"); + show_mnt_opts(m, mnt); + + /* Tagged fields ("foo:X" or "bar") */ + if (IS_MNT_SHARED(mnt)) + seq_printf(m, " shared:%i", mnt->mnt_group_id); + if (IS_MNT_SLAVE(mnt)) + seq_printf(m, " master:%i", mnt->mnt_master->mnt_group_id); + if (IS_MNT_UNBINDABLE(mnt)) + seq_puts(m, " unbindable"); + + /* Filesystem specific data */ + seq_puts(m, " - "); + show_type(m, sb); + seq_putc(m, ' '); + mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none"); + seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw"); + show_sb_opts(m, sb); + if (sb->s_op->show_options) + err = sb->s_op->show_options(m, mnt); + seq_putc(m, '\n'); + return err; +} + +const struct seq_operations mountinfo_op = { + .start = m_start, + .next = m_next, + .stop = m_stop, + .show = show_mountinfo, +}; + static int show_vfsstat(struct seq_file *m, void *v) { struct vfsmount *mnt = list_entry(v, struct vfsmount, mnt_list); @@ -822,7 +895,7 @@ static int show_vfsstat(struct seq_file *m, void *v) /* file system type */ seq_puts(m, "with fstype "); - mangle(m, mnt->mnt_sb->s_type->name); + show_type(m, mnt->mnt_sb); /* optional statistics */ if (mnt->mnt_sb->s_op->show_stats) { |