Commit 79c1cb7a authored by Linus Torvalds's avatar Linus Torvalds

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

* '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)
parents b0d19a37 97e7e0f7
......@@ -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
------------------------------------------------------------------------------
......@@ -1746,12 +1746,21 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
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 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
* 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);
......
This diff is collapsed.
......@@ -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;
}
......
......@@ -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 */
......@@ -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 mountstats_open(struct inode *inode, struct file *file)
static int mountinfo_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();
return mounts_open_common(inode, file, &mountinfo_op);
}
put_task_struct(task);
}
static const struct file_operations proc_mountinfo_operations = {
.open = mountinfo_open,
.read = seq_read,
.llseek = seq_lseek,
.release = mounts_release,
.poll = mounts_poll,
};
if (mnt_ns)
m->private = mnt_ns;
else {
seq_release(inode, file);
ret = -EINVAL;
}
}
return ret;
static int mountstats_open(struct inode *inode, struct file *file)
{
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),
......
......@@ -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);
......
......@@ -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;
}
......
......@@ -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.. */
......
......@@ -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
......@@ -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
......
......@@ -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 *);
......
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