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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

Browse Source 
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  [patch 7/7] vfs: mountinfo: show dominating group id
  [patch 6/7] vfs: mountinfo: add /proc/<pid>/mountinfo
  [patch 5/7] vfs: mountinfo: allow using process root
  [patch 4/7] vfs: mountinfo: add mount peer group ID
  [patch 3/7] vfs: mountinfo: add mount ID
  [patch 2/7] vfs: mountinfo: add seq_file_root()
  [patch 1/7] vfs: mountinfo: add dentry_path()
  [PATCH] remove unused label in xattr.c (noise from ro-bind)
This commit is contained in:
Linus Torvalds 2008-04-23 12:24:19 -07:00
commit 79c1cb7a8c
12 changed files with 573 additions and 138 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
Documentation/filesystems/proc.txt
View File

@ -43,6 +43,7 @@ Table of Contents
2.13 /proc/<pid>/oom_score - Display current oom-killer score
2.14 /proc/<pid>/io - Display the IO accounting fields
2.15 /proc/<pid>/coredump_filter - Core dump filtering settings
2.16 /proc/<pid>/mountinfo - Information about mounts
------------------------------------------------------------------------------
Preface
@ -2348,4 +2349,41 @@ For example:
$ echo 0x7 > /proc/self/coredump_filter
$ ./some_program
2.16 /proc/<pid>/mountinfo - Information about mounts
--------------------------------------------------------
This file contains lines of the form:
36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue
(1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11)
(1) mount ID: unique identifier of the mount (may be reused after umount)
(2) parent ID: ID of parent (or of self for the top of the mount tree)
(3) major:minor: value of st_dev for files on filesystem
(4) root: root of the mount within the filesystem
(5) mount point: mount point relative to the process's root
(6) mount options: per mount options
(7) optional fields: zero or more fields of the form "tag[:value]"
(8) separator: marks the end of the optional fields
(9) filesystem type: name of filesystem of the form "type[.subtype]"
(10) mount source: filesystem specific information or "none"
(11) super options: per super block options
Parsers should ignore all unrecognised optional fields. Currently the
possible optional fields are:
shared:X mount is shared in peer group X
master:X mount is slave to peer group X
propagate_from:X mount is slave and receives propagation from peer group X (*)
unbindable mount is unbindable
(*) X is the closest dominant peer group under the process's root. If
X is the immediate master of the mount, or if there's no dominant peer
group under the same root, then only the "master:X" field is present
and not the "propagate_from:X" field.
For more information on mount propagation see:
Documentation/filesystems/sharedsubtree.txt
------------------------------------------------------------------------------

112
fs/dcache.c
View File

@ -1746,12 +1746,21 @@ shouldnt_be_hashed:
goto shouldnt_be_hashed;
}
static int prepend(char **buffer, int *buflen, const char *str,
int namelen)
{
*buflen -= namelen;
if (*buflen < 0)
return -ENAMETOOLONG;
*buffer -= namelen;
memcpy(*buffer, str, namelen);
return 0;
}
/**
* d_path - return the path of a dentry
* @dentry: dentry to report
* @vfsmnt: vfsmnt to which the dentry belongs
* @root: root dentry
* @rootmnt: vfsmnt to which the root dentry belongs
* @path: the dentry/vfsmount to report
* @root: root vfsmnt/dentry (may be modified by this function)
* @buffer: buffer to return value in
* @buflen: buffer length
*
@ -1761,23 +1770,22 @@ shouldnt_be_hashed:
* Returns the buffer or an error code if the path was too long.
*
* "buflen" should be positive. Caller holds the dcache_lock.
*
* If path is not reachable from the supplied root, then the value of
* root is changed (without modifying refcounts).
*/
static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
struct path *root, char *buffer, int buflen)
char *__d_path(const struct path *path, struct path *root,
char *buffer, int buflen)
{
struct dentry *dentry = path->dentry;
struct vfsmount *vfsmnt = path->mnt;
char * end = buffer+buflen;
char * retval;
int namelen;
*--end = '\0';
buflen--;
if (!IS_ROOT(dentry) && d_unhashed(dentry)) {
buflen -= 10;
end -= 10;
if (buflen < 0)
prepend(&end, &buflen, "\0", 1);
if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
(prepend(&end, &buflen, " (deleted)", 10) != 0))
goto Elong;
memcpy(end, " (deleted)", 10);
}
if (buflen < 1)
goto Elong;
@ -1804,13 +1812,10 @@ static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
}
parent = dentry->d_parent;
prefetch(parent);
namelen = dentry->d_name.len;
buflen -= namelen + 1;
if (buflen < 0)
if ((prepend(&end, &buflen, dentry->d_name.name,
dentry->d_name.len) != 0) ||
(prepend(&end, &buflen, "/", 1) != 0))
goto Elong;
end -= namelen;
memcpy(end, dentry->d_name.name, namelen);
*--end = '/';
retval = end;
dentry = parent;
}
@ -1818,12 +1823,12 @@ static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt,
return retval;
global_root:
namelen = dentry->d_name.len;
buflen -= namelen;
if (buflen < 0)
retval += 1; /* hit the slash */
if (prepend(&retval, &buflen, dentry->d_name.name,
dentry->d_name.len) != 0)
goto Elong;
retval -= namelen-1; /* hit the slash */
memcpy(retval, dentry->d_name.name, namelen);
root->mnt = vfsmnt;
root->dentry = dentry;
return retval;
Elong:
return ERR_PTR(-ENAMETOOLONG);
@ -1846,6 +1851,7 @@ char *d_path(struct path *path, char *buf, int buflen)
{
char *res;
struct path root;
struct path tmp;
/*
* We have various synthetic filesystems that never get mounted. On
@ -1859,10 +1865,11 @@ char *d_path(struct path *path, char *buf, int buflen)
read_lock(&current->fs->lock);
root = current->fs->root;
path_get(&current->fs->root);
path_get(&root);
read_unlock(&current->fs->lock);
spin_lock(&dcache_lock);
res = __d_path(path->dentry, path->mnt, &root, buf, buflen);
tmp = root;
res = __d_path(path, &tmp, buf, buflen);
spin_unlock(&dcache_lock);
path_put(&root);
return res;
@ -1889,6 +1896,48 @@ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen,
return memcpy(buffer, temp, sz);
}
/*
* Write full pathname from the root of the filesystem into the buffer.
*/
char *dentry_path(struct dentry *dentry, char *buf, int buflen)
{
char *end = buf + buflen;
char *retval;
spin_lock(&dcache_lock);
prepend(&end, &buflen, "\0", 1);
if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
(prepend(&end, &buflen, "//deleted", 9) != 0))
goto Elong;
if (buflen < 1)
goto Elong;
/* Get '/' right */
retval = end-1;
*retval = '/';
for (;;) {
struct dentry *parent;
if (IS_ROOT(dentry))
break;
parent = dentry->d_parent;
prefetch(parent);
if ((prepend(&end, &buflen, dentry->d_name.name,
dentry->d_name.len) != 0) ||
(prepend(&end, &buflen, "/", 1) != 0))
goto Elong;
retval = end;
dentry = parent;
}
spin_unlock(&dcache_lock);
return retval;
Elong:
spin_unlock(&dcache_lock);
return ERR_PTR(-ENAMETOOLONG);
}
/*
* NOTE! The user-level library version returns a
* character pointer. The kernel system call just
@ -1918,9 +1967,9 @@ asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
read_lock(&current->fs->lock);
pwd = current->fs->pwd;
path_get(&current->fs->pwd);
path_get(&pwd);
root = current->fs->root;
path_get(&current->fs->root);
path_get(&root);
read_unlock(&current->fs->lock);
error = -ENOENT;
@ -1928,9 +1977,10 @@ asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
spin_lock(&dcache_lock);
if (pwd.dentry->d_parent == pwd.dentry || !d_unhashed(pwd.dentry)) {
unsigned long len;
struct path tmp = root;
char * cwd;
cwd = __d_path(pwd.dentry, pwd.mnt, &root, page, PAGE_SIZE);
cwd = __d_path(&pwd, &tmp, page, PAGE_SIZE);
spin_unlock(&dcache_lock);
error = PTR_ERR(cwd);

265
fs/namespace.c
View File

@ -27,6 +27,7 @@
#include <linux/mount.h>
#include <linux/ramfs.h>
#include <linux/log2.h>
#include <linux/idr.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include "pnode.h"
@ -39,6 +40,8 @@
__cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock);
static int event;
static DEFINE_IDA(mnt_id_ida);
static DEFINE_IDA(mnt_group_ida);
static struct list_head *mount_hashtable __read_mostly;
static struct kmem_cache *mnt_cache __read_mostly;
@ -58,10 +61,63 @@ static inline unsigned long hash(struct vfsmount *mnt, struct dentry *dentry)
#define MNT_WRITER_UNDERFLOW_LIMIT -(1<<16)
/* allocation is serialized by namespace_sem */
static int mnt_alloc_id(struct vfsmount *mnt)
{
int res;
retry:
ida_pre_get(&mnt_id_ida, GFP_KERNEL);
spin_lock(&vfsmount_lock);
res = ida_get_new(&mnt_id_ida, &mnt->mnt_id);
spin_unlock(&vfsmount_lock);
if (res == -EAGAIN)
goto retry;
return res;
}
static void mnt_free_id(struct vfsmount *mnt)
{
spin_lock(&vfsmount_lock);
ida_remove(&mnt_id_ida, mnt->mnt_id);
spin_unlock(&vfsmount_lock);
}
/*
* Allocate a new peer group ID
*
* mnt_group_ida is protected by namespace_sem
*/
static int mnt_alloc_group_id(struct vfsmount *mnt)
{
if (!ida_pre_get(&mnt_group_ida, GFP_KERNEL))
return -ENOMEM;
return ida_get_new_above(&mnt_group_ida, 1, &mnt->mnt_group_id);
}
/*
* Release a peer group ID
*/
void mnt_release_group_id(struct vfsmount *mnt)
{
ida_remove(&mnt_group_ida, mnt->mnt_group_id);
mnt->mnt_group_id = 0;
}
struct vfsmount *alloc_vfsmnt(const char *name)
{
struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
if (mnt) {
int err;
err = mnt_alloc_id(mnt);
if (err) {
kmem_cache_free(mnt_cache, mnt);
return NULL;
}
atomic_set(&mnt->mnt_count, 1);
INIT_LIST_HEAD(&mnt->mnt_hash);
INIT_LIST_HEAD(&mnt->mnt_child);
@ -353,6 +409,7 @@ EXPORT_SYMBOL(simple_set_mnt);
void free_vfsmnt(struct vfsmount *mnt)
{
kfree(mnt->mnt_devname);
mnt_free_id(mnt);
kmem_cache_free(mnt_cache, mnt);
}
@ -499,6 +556,17 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
struct vfsmount *mnt = alloc_vfsmnt(old->mnt_devname);
if (mnt) {
if (flag & (CL_SLAVE | CL_PRIVATE))
mnt->mnt_group_id = 0; /* not a peer of original */
else
mnt->mnt_group_id = old->mnt_group_id;
if ((flag & CL_MAKE_SHARED) && !mnt->mnt_group_id) {
int err = mnt_alloc_group_id(mnt);
if (err)
goto out_free;
}
mnt->mnt_flags = old->mnt_flags;
atomic_inc(&sb->s_active);
mnt->mnt_sb = sb;
@ -528,6 +596,10 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
}
}
return mnt;
out_free:
free_vfsmnt(mnt);
return NULL;
}
static inline void __mntput(struct vfsmount *mnt)
@ -652,20 +724,21 @@ void save_mount_options(struct super_block *sb, char *options)
}
EXPORT_SYMBOL(save_mount_options);
#ifdef CONFIG_PROC_FS
/* iterator */
static void *m_start(struct seq_file *m, loff_t *pos)
{
struct mnt_namespace *n = m->private;
struct proc_mounts *p = m->private;
down_read(&namespace_sem);
return seq_list_start(&n->list, *pos);
return seq_list_start(&p->ns->list, *pos);
}
static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
struct mnt_namespace *n = m->private;
struct proc_mounts *p = m->private;
return seq_list_next(v, &n->list, pos);
return seq_list_next(v, &p->ns->list, pos);
}
static void m_stop(struct seq_file *m, void *v)
@ -673,20 +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" },
@ -695,40 +778,108 @@ 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");
return err;
}
struct seq_operations mounts_op = {
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 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)) {
int master = mnt->mnt_master->mnt_group_id;
int dom = get_dominating_id(mnt, &p->root);
seq_printf(m, " master:%i", master);
if (dom && dom != master)
seq_printf(m, " propagate_from:%i", dom);
}
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);
@ -749,7 +900,7 @@ 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) {
@ -761,12 +912,13 @@ static int show_vfsstat(struct seq_file *m, void *v)
return err;
}
struct seq_operations mountstats_op = {
const struct seq_operations mountstats_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = show_vfsstat,
};
#endif /* CONFIG_PROC_FS */
/**
* may_umount_tree - check if a mount tree is busy
@ -1108,6 +1260,33 @@ void drop_collected_mounts(struct vfsmount *mnt)
release_mounts(&umount_list);
}
static void cleanup_group_ids(struct vfsmount *mnt, struct vfsmount *end)
{
struct vfsmount *p;
for (p = mnt; p != end; p = next_mnt(p, mnt)) {
if (p->mnt_group_id && !IS_MNT_SHARED(p))
mnt_release_group_id(p);
}
}
static int invent_group_ids(struct vfsmount *mnt, bool recurse)
{
struct vfsmount *p;
for (p = mnt; p; p = recurse ? next_mnt(p, mnt) : NULL) {
if (!p->mnt_group_id && !IS_MNT_SHARED(p)) {
int err = mnt_alloc_group_id(p);
if (err) {
cleanup_group_ids(mnt, p);
return err;
}
}
}
return 0;
}
/*
* @source_mnt : mount tree to be attached
* @nd : place the mount tree @source_mnt is attached
@ -1178,9 +1357,16 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt,
struct vfsmount *dest_mnt = path->mnt;
struct dentry *dest_dentry = path->dentry;
struct vfsmount *child, *p;
int err;
if (propagate_mnt(dest_mnt, dest_dentry, source_mnt, &tree_list))
return -EINVAL;
if (IS_MNT_SHARED(dest_mnt)) {
err = invent_group_ids(source_mnt, true);
if (err)
goto out;
}
err = propagate_mnt(dest_mnt, dest_dentry, source_mnt, &tree_list);
if (err)
goto out_cleanup_ids;
if (IS_MNT_SHARED(dest_mnt)) {
for (p = source_mnt; p; p = next_mnt(p, source_mnt))
@ -1203,6 +1389,12 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt,
}
spin_unlock(&vfsmount_lock);
return 0;
out_cleanup_ids:
if (IS_MNT_SHARED(dest_mnt))
cleanup_group_ids(source_mnt, NULL);
out:
return err;
}
static int graft_tree(struct vfsmount *mnt, struct path *path)
@ -1243,6 +1435,7 @@ static noinline int do_change_type(struct nameidata *nd, int flag)
struct vfsmount *m, *mnt = nd->path.mnt;
int recurse = flag & MS_REC;
int type = flag & ~MS_REC;
int err = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@ -1251,12 +1444,20 @@ static noinline int do_change_type(struct nameidata *nd, int flag)
return -EINVAL;
down_write(&namespace_sem);
if (type == MS_SHARED) {
err = invent_group_ids(mnt, recurse);
if (err)
goto out_unlock;
}
spin_lock(&vfsmount_lock);
for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL))
change_mnt_propagation(m, type);
spin_unlock(&vfsmount_lock);
out_unlock:
up_write(&namespace_sem);
return 0;
return err;
}
/*

56
fs/pnode.c
View File

@ -28,6 +28,57 @@ static inline struct vfsmount *next_slave(struct vfsmount *p)
return list_entry(p->mnt_slave.next, struct vfsmount, mnt_slave);
}
/*
* Return true if path is reachable from root
*
* namespace_sem is held, and mnt is attached
*/
static bool is_path_reachable(struct vfsmount *mnt, struct dentry *dentry,
const struct path *root)
{
while (mnt != root->mnt && mnt->mnt_parent != mnt) {
dentry = mnt->mnt_mountpoint;
mnt = mnt->mnt_parent;
}
return mnt == root->mnt && is_subdir(dentry, root->dentry);
}
static struct vfsmount *get_peer_under_root(struct vfsmount *mnt,
struct mnt_namespace *ns,
const struct path *root)
{
struct vfsmount *m = mnt;
do {
/* Check the namespace first for optimization */
if (m->mnt_ns == ns && is_path_reachable(m, m->mnt_root, root))
return m;
m = next_peer(m);
} while (m != mnt);
return NULL;
}
/*
* Get ID of closest dominating peer group having a representative
* under the given root.
*
* Caller must hold namespace_sem
*/
int get_dominating_id(struct vfsmount *mnt, const struct path *root)
{
struct vfsmount *m;
for (m = mnt->mnt_master; m != NULL; m = m->mnt_master) {
struct vfsmount *d = get_peer_under_root(m, mnt->mnt_ns, root);
if (d)
return d->mnt_group_id;
}
return 0;
}
static int do_make_slave(struct vfsmount *mnt)
{
struct vfsmount *peer_mnt = mnt, *master = mnt->mnt_master;
@ -46,7 +97,11 @@ static int do_make_slave(struct vfsmount *mnt)
if (peer_mnt == mnt)
peer_mnt = NULL;
}
if (IS_MNT_SHARED(mnt) && list_empty(&mnt->mnt_share))
mnt_release_group_id(mnt);
list_del_init(&mnt->mnt_share);
mnt->mnt_group_id = 0;
if (peer_mnt)
master = peer_mnt;
@ -68,7 +123,6 @@ static int do_make_slave(struct vfsmount *mnt)
}
mnt->mnt_master = master;
CLEAR_MNT_SHARED(mnt);
INIT_LIST_HEAD(&mnt->mnt_slave_list);
return 0;
}

1
fs/pnode.h
View File

@ -36,4 +36,5 @@ int propagate_mnt(struct vfsmount *, struct dentry *, struct vfsmount *,
int propagate_umount(struct list_head *);
int propagate_mount_busy(struct vfsmount *, int);
void mnt_release_group_id(struct vfsmount *);
int get_dominating_id(struct vfsmount *mnt, const struct path *root);
#endif /* _LINUX_PNODE_H */

123
fs/proc/base.c
View File

@ -502,17 +502,14 @@ static const struct inode_operations proc_def_inode_operations = {
.setattr = proc_setattr,
};
extern const struct seq_operations mounts_op;
struct proc_mounts {
struct seq_file m;
int event;
};
static int mounts_open(struct inode *inode, struct file *file)
static int mounts_open_common(struct inode *inode, struct file *file,
const struct seq_operations *op)
{
struct task_struct *task = get_proc_task(inode);
struct nsproxy *nsp;
struct mnt_namespace *ns = NULL;
struct fs_struct *fs = NULL;
struct path root;
struct proc_mounts *p;
int ret = -EINVAL;
@ -525,40 +522,61 @@ static int mounts_open(struct inode *inode, struct file *file)
get_mnt_ns(ns);
}
rcu_read_unlock();
if (ns)
fs = get_fs_struct(task);
put_task_struct(task);
}
if (ns) {
ret = -ENOMEM;
p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
if (p) {
file->private_data = &p->m;
ret = seq_open(file, &mounts_op);
if (!ret) {
p->m.private = ns;
p->event = ns->event;
return 0;
}
kfree(p);
}
put_mnt_ns(ns);
}
if (!ns)
goto err;
if (!fs)
goto err_put_ns;
read_lock(&fs->lock);
root = fs->root;
path_get(&root);
read_unlock(&fs->lock);
put_fs_struct(fs);
ret = -ENOMEM;
p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
if (!p)
goto err_put_path;
file->private_data = &p->m;
ret = seq_open(file, op);
if (ret)
goto err_free;
p->m.private = p;
p->ns = ns;
p->root = root;
p->event = ns->event;
return 0;
err_free:
kfree(p);
err_put_path:
path_put(&root);
err_put_ns:
put_mnt_ns(ns);
err:
return ret;
}
static int mounts_release(struct inode *inode, struct file *file)
{
struct seq_file *m = file->private_data;
struct mnt_namespace *ns = m->private;
put_mnt_ns(ns);
struct proc_mounts *p = file->private_data;
path_put(&p->root);
put_mnt_ns(p->ns);
return seq_release(inode, file);
}
static unsigned mounts_poll(struct file *file, poll_table *wait)
{
struct proc_mounts *p = file->private_data;
struct mnt_namespace *ns = p->m.private;
struct mnt_namespace *ns = p->ns;
unsigned res = 0;
poll_wait(file, &ns->poll, wait);
@ -573,6 +591,11 @@ static unsigned mounts_poll(struct file *file, poll_table *wait)
return res;
}
static int mounts_open(struct inode *inode, struct file *file)
{
return mounts_open_common(inode, file, &mounts_op);
}
static const struct file_operations proc_mounts_operations = {
.open = mounts_open,
.read = seq_read,
@ -581,38 +604,22 @@ static const struct file_operations proc_mounts_operations = {
.poll = mounts_poll,
};
extern const struct seq_operations mountstats_op;
static int mountinfo_open(struct inode *inode, struct file *file)
{
return mounts_open_common(inode, file, &mountinfo_op);
}
static const struct file_operations proc_mountinfo_operations = {
.open = mountinfo_open,
.read = seq_read,
.llseek = seq_lseek,
.release = mounts_release,
.poll = mounts_poll,
};
static int mountstats_open(struct inode *inode, struct file *file)
{
int ret = seq_open(file, &mountstats_op);
if (!ret) {
struct seq_file *m = file->private_data;
struct nsproxy *nsp;
struct mnt_namespace *mnt_ns = NULL;
struct task_struct *task = get_proc_task(inode);
if (task) {
rcu_read_lock();
nsp = task_nsproxy(task);
if (nsp) {
mnt_ns = nsp->mnt_ns;
if (mnt_ns)
get_mnt_ns(mnt_ns);
}
rcu_read_unlock();
put_task_struct(task);
}
if (mnt_ns)
m->private = mnt_ns;
else {
seq_release(inode, file);
ret = -EINVAL;
}
}
return ret;
return mounts_open_common(inode, file, &mountstats_op);
}
static const struct file_operations proc_mountstats_operations = {
@ -2309,6 +2316,7 @@ static const struct pid_entry tgid_base_stuff[] = {
LNK("root", root),
LNK("exe", exe),
REG("mounts", S_IRUGO, mounts),
REG("mountinfo", S_IRUGO, mountinfo),
REG("mountstats", S_IRUSR, mountstats),
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, clear_refs),
@ -2641,6 +2649,7 @@ static const struct pid_entry tid_base_stuff[] = {
LNK("root", root),
LNK("exe", exe),
REG("mounts", S_IRUGO, mounts),
REG("mountinfo", S_IRUGO, mountinfo),
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("clear_refs", S_IWUSR, clear_refs),
REG("smaps", S_IRUGO, smaps),

95
fs/seq_file.c
View File

@ -350,28 +350,40 @@ int seq_printf(struct seq_file *m, const char *f, ...)
}
EXPORT_SYMBOL(seq_printf);
static char *mangle_path(char *s, char *p, char *esc)
{
while (s <= p) {
char c = *p++;
if (!c) {
return s;
} else if (!strchr(esc, c)) {
*s++ = c;
} else if (s + 4 > p) {
break;
} else {
*s++ = '\\';
*s++ = '0' + ((c & 0300) >> 6);
*s++ = '0' + ((c & 070) >> 3);
*s++ = '0' + (c & 07);
}
}
return NULL;
}
/*
* return the absolute path of 'dentry' residing in mount 'mnt'.
*/
int seq_path(struct seq_file *m, struct path *path, char *esc)
{
if (m->count < m->size) {
char *s = m->buf + m->count;
char *p = d_path(path, s, m->size - m->count);
if (!IS_ERR(p)) {
while (s <= p) {
char c = *p++;
if (!c) {
p = m->buf + m->count;
m->count = s - m->buf;
return s - p;
} else if (!strchr(esc, c)) {
*s++ = c;
} else if (s + 4 > p) {
break;
} else {
*s++ = '\\';
*s++ = '0' + ((c & 0300) >> 6);
*s++ = '0' + ((c & 070) >> 3);
*s++ = '0' + (c & 07);
}
s = mangle_path(s, p, esc);
if (s) {
p = m->buf + m->count;
m->count = s - m->buf;
return s - p;
}
}
}
@ -380,6 +392,57 @@ int seq_path(struct seq_file *m, struct path *path, char *esc)
}
EXPORT_SYMBOL(seq_path);
/*
* Same as seq_path, but relative to supplied root.
*
* root may be changed, see __d_path().
*/
int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
char *esc)
{
int err = -ENAMETOOLONG;
if (m->count < m->size) {
char *s = m->buf + m->count;
char *p;
spin_lock(&dcache_lock);
p = __d_path(path, root, s, m->size - m->count);
spin_unlock(&dcache_lock);
err = PTR_ERR(p);
if (!IS_ERR(p)) {
s = mangle_path(s, p, esc);
if (s) {
p = m->buf + m->count;
m->count = s - m->buf;
return 0;
}
}
}
m->count = m->size;
return err;
}
/*
* returns the path of the 'dentry' from the root of its filesystem.
*/
int seq_dentry(struct seq_file *m, struct dentry *dentry, char *esc)
{
if (m->count < m->size) {
char *s = m->buf + m->count;
char *p = dentry_path(dentry, s, m->size - m->count);
if (!IS_ERR(p)) {
s = mangle_path(s, p, esc);
if (s) {
p = m->buf + m->count;
m->count = s - m->buf;
return s - p;
}
}
}
m->count = m->size;
return -1;
}
static void *single_start(struct seq_file *p, loff_t *pos)
{
return NULL + (*pos == 0);

1
fs/xattr.c
View File

@ -307,7 +307,6 @@ sys_fsetxattr(int fd, char __user *name, void __user *value,
error = setxattr(dentry, name, value, size, flags);
mnt_drop_write(f->f_path.mnt);
}
out_fput:
fput(f);
return error;
}

2
include/linux/dcache.h
View File

@ -301,7 +301,9 @@ extern int d_validate(struct dentry *, struct dentry *);
*/
extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
extern char *__d_path(const struct path *path, struct path *root, char *, int);
extern char *d_path(struct path *, char *, int);
extern char *dentry_path(struct dentry *, char *, int);
/* Allocation counts.. */

12
include/linux/mnt_namespace.h
View File

@ -5,6 +5,7 @@
#include <linux/mount.h>
#include <linux/sched.h>
#include <linux/nsproxy.h>
#include <linux/seq_file.h>
struct mnt_namespace {
atomic_t count;
@ -14,6 +15,13 @@ struct mnt_namespace {
int event;
};
struct proc_mounts {
struct seq_file m; /* must be the first element */
struct mnt_namespace *ns;
struct path root;
int event;
};
extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *,
struct fs_struct *);
extern void __put_mnt_ns(struct mnt_namespace *ns);
@ -37,5 +45,9 @@ static inline void get_mnt_ns(struct mnt_namespace *ns)
atomic_inc(&ns->count);
}
extern const struct seq_operations mounts_op;
extern const struct seq_operations mountinfo_op;
extern const struct seq_operations mountstats_op;
#endif
#endif

2
include/linux/mount.h
View File

@ -56,6 +56,8 @@ struct vfsmount {
struct list_head mnt_slave; /* slave list entry */
struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */
struct mnt_namespace *mnt_ns; /* containing namespace */
int mnt_id; /* mount identifier */
int mnt_group_id; /* peer group identifier */
/*
* We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
* to let these frequently modified fields in a separate cache line

4
include/linux/seq_file.h
View File

@ -10,6 +10,7 @@ struct seq_operations;
struct file;
struct path;
struct inode;
struct dentry;
struct seq_file {
char *buf;
@ -44,6 +45,9 @@ int seq_printf(struct seq_file *, const char *, ...)
__attribute__ ((format (printf,2,3)));
int seq_path(struct seq_file *, struct path *, char *);
int seq_dentry(struct seq_file *, struct dentry *, char *);
int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
char *esc);
int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
int single_release(struct inode *, struct file *);