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vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
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rationale: that stuff is far tighter bound to fs/namespace.c than to
the guts of procfs proper.

Signed-off-by: Al Viro <[email protected]>
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Al Viro committed Jan 4, 2012
1 parent 3a2393d commit 0226f49
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Showing 6 changed files with 368 additions and 351 deletions.
2 changes: 2 additions & 0 deletions fs/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,8 @@ else
obj-y += no-block.o
endif

obj-$(CONFIG_PROC_FS) += proc_namespace.o

obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
obj-y += notify/
obj-$(CONFIG_EPOLL) += eventpoll.o
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24 changes: 24 additions & 0 deletions fs/mount.h
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Original file line number Diff line number Diff line change
@@ -1,4 +1,14 @@
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/poll.h>

struct mnt_namespace {
atomic_t count;
struct vfsmount * root;
struct list_head list;
wait_queue_head_t poll;
int event;
};

struct mnt_pcp {
int mnt_count;
Expand Down Expand Up @@ -49,3 +59,17 @@ static inline int mnt_has_parent(struct mount *mnt)
}

extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);

static inline void get_mnt_ns(struct mnt_namespace *ns)
{
atomic_inc(&ns->count);
}

struct proc_mounts {
struct seq_file m; /* must be the first element */
struct mnt_namespace *ns;
struct path root;
int (*show)(struct seq_file *, struct vfsmount *);
};

extern const struct seq_operations mounts_op;
218 changes: 7 additions & 211 deletions fs/namespace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -898,18 +898,18 @@ void replace_mount_options(struct super_block *sb, char *options)
EXPORT_SYMBOL(replace_mount_options);

#ifdef CONFIG_PROC_FS
/* iterator */
/* iterator; we want it to have access to namespace_sem, thus here... */
static void *m_start(struct seq_file *m, loff_t *pos)
{
struct proc_mounts *p = m->private;
struct proc_mounts *p = container_of(m, struct proc_mounts, m);

down_read(&namespace_sem);
return seq_list_start(&p->ns->list, *pos);
}

static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
struct proc_mounts *p = m->private;
struct proc_mounts *p = container_of(m, struct proc_mounts, m);

return seq_list_next(v, &p->ns->list, pos);
}
Expand All @@ -919,222 +919,18 @@ static void m_stop(struct seq_file *m, void *v)
up_read(&namespace_sem);
}

int mnt_had_events(struct proc_mounts *p)
{
struct mnt_namespace *ns = p->ns;
int res = 0;

br_read_lock(vfsmount_lock);
if (p->m.poll_event != ns->event) {
p->m.poll_event = ns->event;
res = 1;
}
br_read_unlock(vfsmount_lock);

return res;
}

struct proc_fs_info {
int flag;
const char *str;
};

static int show_sb_opts(struct seq_file *m, struct super_block *sb)
{
static const struct proc_fs_info fs_info[] = {
{ MS_SYNCHRONOUS, ",sync" },
{ MS_DIRSYNC, ",dirsync" },
{ MS_MANDLOCK, ",mand" },
{ 0, NULL }
};
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);
}

return security_sb_show_options(m, sb);
}

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" },
{ MNT_NOATIME, ",noatime" },
{ MNT_NODIRATIME, ",nodiratime" },
{ MNT_RELATIME, ",relatime" },
{ 0, NULL }
};
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)
static int m_show(struct seq_file *m, void *v)
{
struct proc_mounts *p = container_of(m, struct proc_mounts, m);
struct mount *r = list_entry(v, struct mount, mnt_list);
struct vfsmount *mnt = &r->mnt;
int err = 0;
struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };

if (mnt->mnt_sb->s_op->show_devname) {
err = mnt->mnt_sb->s_op->show_devname(m, mnt);
if (err)
goto out;
} else {
mangle(m, r->mnt_devname ? r->mnt_devname : "none");
}
seq_putc(m, ' ');
seq_path(m, &mnt_path, " \t\n\\");
seq_putc(m, ' ');
show_type(m, mnt->mnt_sb);
seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
err = show_sb_opts(m, mnt->mnt_sb);
if (err)
goto out;
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");
out:
return err;
return p->show(m, &r->mnt);
}

const struct seq_operations mounts_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = show_vfsmnt
};

static int show_mountinfo(struct seq_file *m, void *v)
{
struct proc_mounts *p = m->private;
struct mount *r = list_entry(v, struct mount, mnt_list);
struct vfsmount *mnt = &r->mnt;
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 ", r->mnt_id, r->mnt_parent->mnt_id,
MAJOR(sb->s_dev), MINOR(sb->s_dev));
if (sb->s_op->show_path)
err = sb->s_op->show_path(m, mnt);
else
seq_dentry(m, mnt->mnt_root, " \t\n\\");
if (err)
goto out;
seq_putc(m, ' ');

/* mountpoints outside of chroot jail will give SEQ_SKIP on this */
err = seq_path_root(m, &mnt_path, &root, " \t\n\\");
if (err)
goto out;

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(r))
seq_printf(m, " shared:%i", r->mnt_group_id);
if (IS_MNT_SLAVE(r)) {
int master = r->mnt_master->mnt_group_id;
int dom = get_dominating_id(r, &p->root);
seq_printf(m, " master:%i", master);
if (dom && dom != master)
seq_printf(m, " propagate_from:%i", dom);
}
if (IS_MNT_UNBINDABLE(r))
seq_puts(m, " unbindable");

/* Filesystem specific data */
seq_puts(m, " - ");
show_type(m, sb);
seq_putc(m, ' ');
if (sb->s_op->show_devname)
err = sb->s_op->show_devname(m, mnt);
else
mangle(m, r->mnt_devname ? r->mnt_devname : "none");
if (err)
goto out;
seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
err = show_sb_opts(m, sb);
if (err)
goto out;
if (sb->s_op->show_options)
err = sb->s_op->show_options(m, mnt);
seq_putc(m, '\n');
out:
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 mount *r = list_entry(v, struct mount, mnt_list);
struct vfsmount *mnt = &r->mnt;
struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
int err = 0;

/* device */
if (mnt->mnt_sb->s_op->show_devname) {
seq_puts(m, "device ");
err = mnt->mnt_sb->s_op->show_devname(m, mnt);
} else {
if (r->mnt_devname) {
seq_puts(m, "device ");
mangle(m, r->mnt_devname);
} else
seq_puts(m, "no device");
}

/* mount point */
seq_puts(m, " mounted on ");
seq_path(m, &mnt_path, " \t\n\\");
seq_putc(m, ' ');

/* file system type */
seq_puts(m, "with fstype ");
show_type(m, mnt->mnt_sb);

/* optional statistics */
if (mnt->mnt_sb->s_op->show_stats) {
seq_putc(m, ' ');
if (!err)
err = mnt->mnt_sb->s_op->show_stats(m, mnt);
}

seq_putc(m, '\n');
return err;
}

const struct seq_operations mountstats_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = show_vfsstat,
.show = m_show,
};
#endif /* CONFIG_PROC_FS */

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