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path: root/fs/autofs4/waitq.c
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Diffstat (limited to 'fs/autofs4/waitq.c')
-rw-r--r--fs/autofs4/waitq.c109
1 files changed, 75 insertions, 34 deletions
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 2341375386f..116fd38ee47 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -42,10 +42,8 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
while (wq) {
nwq = wq->next;
wq->status = -ENOENT; /* Magic is gone - report failure */
- if (wq->name.name) {
- kfree(wq->name.name);
- wq->name.name = NULL;
- }
+ kfree(wq->name.name);
+ wq->name.name = NULL;
wq->wait_ctr--;
wake_up_interruptible(&wq->queue);
wq = nwq;
@@ -56,26 +54,27 @@ void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
mutex_unlock(&sbi->wq_mutex);
}
-static int autofs4_write(struct file *file, const void *addr, int bytes)
+static int autofs4_write(struct autofs_sb_info *sbi,
+ struct file *file, const void *addr, int bytes)
{
unsigned long sigpipe, flags;
mm_segment_t fs;
const char *data = (const char *)addr;
ssize_t wr = 0;
- /** WARNING: this is not safe for writing more than PIPE_BUF bytes! **/
-
sigpipe = sigismember(&current->pending.signal, SIGPIPE);
/* Save pointer to user space and point back to kernel space */
fs = get_fs();
set_fs(KERNEL_DS);
+ mutex_lock(&sbi->pipe_mutex);
while (bytes &&
(wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) {
data += wr;
bytes -= wr;
}
+ mutex_unlock(&sbi->pipe_mutex);
set_fs(fs);
@@ -104,12 +103,13 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
size_t pktsz;
DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d",
- wq->wait_queue_token, wq->name.len, wq->name.name, type);
+ (unsigned long) wq->wait_queue_token, wq->name.len, wq->name.name, type);
memset(&pkt,0,sizeof pkt); /* For security reasons */
pkt.hdr.proto_version = sbi->version;
pkt.hdr.type = type;
+
switch (type) {
/* Kernel protocol v4 missing and expire packets */
case autofs_ptype_missing:
@@ -146,6 +146,7 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
case autofs_ptype_expire_direct:
{
struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet;
+ struct user_namespace *user_ns = sbi->pipe->f_cred->user_ns;
pktsz = sizeof(*packet);
@@ -155,30 +156,25 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
packet->name[wq->name.len] = '\0';
packet->dev = wq->dev;
packet->ino = wq->ino;
- packet->uid = wq->uid;
- packet->gid = wq->gid;
+ packet->uid = from_kuid_munged(user_ns, wq->uid);
+ packet->gid = from_kgid_munged(user_ns, wq->gid);
packet->pid = wq->pid;
packet->tgid = wq->tgid;
break;
}
default:
printk("autofs4_notify_daemon: bad type %d!\n", type);
+ mutex_unlock(&sbi->wq_mutex);
return;
}
- /* Check if we have become catatonic */
- mutex_lock(&sbi->wq_mutex);
- if (!sbi->catatonic) {
- pipe = sbi->pipe;
- get_file(pipe);
- }
+ pipe = get_file(sbi->pipe);
+
mutex_unlock(&sbi->wq_mutex);
- if (pipe) {
- if (autofs4_write(pipe, &pkt, pktsz))
- autofs4_catatonic_mode(sbi);
- fput(pipe);
- }
+ if (autofs4_write(sbi, pipe, &pkt, pktsz))
+ autofs4_catatonic_mode(sbi);
+ fput(pipe);
}
static int autofs4_getpath(struct autofs_sb_info *sbi,
@@ -186,16 +182,26 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
{
struct dentry *root = sbi->sb->s_root;
struct dentry *tmp;
- char *buf = *name;
+ char *buf;
char *p;
- int len = 0;
+ int len;
+ unsigned seq;
+
+rename_retry:
+ buf = *name;
+ len = 0;
- spin_lock(&dcache_lock);
+ seq = read_seqbegin(&rename_lock);
+ rcu_read_lock();
+ spin_lock(&sbi->fs_lock);
for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
len += tmp->d_name.len + 1;
if (!len || --len > NAME_MAX) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
return 0;
}
@@ -208,7 +214,10 @@ static int autofs4_getpath(struct autofs_sb_info *sbi,
p -= tmp->d_name.len;
strncpy(p, tmp->d_name.name, tmp->d_name.len);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
return len;
}
@@ -244,6 +253,9 @@ static int validate_request(struct autofs_wait_queue **wait,
struct autofs_wait_queue *wq;
struct autofs_info *ino;
+ if (sbi->catatonic)
+ return -ENOENT;
+
/* Wait in progress, continue; */
wq = autofs4_find_wait(sbi, qstr);
if (wq) {
@@ -276,6 +288,9 @@ static int validate_request(struct autofs_wait_queue **wait,
if (mutex_lock_interruptible(&sbi->wq_mutex))
return -EINTR;
+ if (sbi->catatonic)
+ return -ENOENT;
+
wq = autofs4_find_wait(sbi, qstr);
if (wq) {
*wait = wq;
@@ -296,6 +311,9 @@ static int validate_request(struct autofs_wait_queue **wait,
* completed while we waited on the mutex ...
*/
if (notify == NFY_MOUNT) {
+ struct dentry *new = NULL;
+ int valid = 1;
+
/*
* If the dentry was successfully mounted while we slept
* on the wait queue mutex we can return success. If it
@@ -303,8 +321,20 @@ static int validate_request(struct autofs_wait_queue **wait,
* a multi-mount with no mount at it's base) we can
* continue on and create a new request.
*/
+ if (!IS_ROOT(dentry)) {
+ if (dentry->d_inode && d_unhashed(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+ new = d_lookup(parent, &dentry->d_name);
+ if (new)
+ dentry = new;
+ }
+ }
if (have_submounts(dentry))
- return 0;
+ valid = 0;
+
+ if (new)
+ dput(new);
+ return valid;
}
return 1;
@@ -317,11 +347,23 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
struct qstr qstr;
char *name;
int status, ret, type;
+ pid_t pid;
+ pid_t tgid;
/* In catatonic mode, we don't wait for nobody */
if (sbi->catatonic)
return -ENOENT;
+ /*
+ * Try translating pids to the namespace of the daemon.
+ *
+ * Zero means failure: we are in an unrelated pid namespace.
+ */
+ pid = task_pid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
+ tgid = task_tgid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
+ if (pid == 0 || tgid == 0)
+ return -ENOENT;
+
if (!dentry->d_inode) {
/*
* A wait for a negative dentry is invalid for certain
@@ -361,7 +403,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
ret = validate_request(&wq, sbi, &qstr, dentry, notify);
if (ret <= 0) {
- if (ret == 0)
+ if (ret != -EINTR)
mutex_unlock(&sbi->wq_mutex);
kfree(qstr.name);
return ret;
@@ -387,11 +429,10 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
wq->ino = autofs4_get_ino(sbi);
wq->uid = current_uid();
wq->gid = current_gid();
- wq->pid = current->pid;
- wq->tgid = current->tgid;
+ wq->pid = pid;
+ wq->tgid = tgid;
wq->status = -EINTR; /* Status return if interrupted */
wq->wait_ctr = 2;
- mutex_unlock(&sbi->wq_mutex);
if (sbi->version < 5) {
if (notify == NFY_MOUNT)
@@ -413,15 +454,15 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
(unsigned long) wq->wait_queue_token, wq->name.len,
wq->name.name, notify);
- /* autofs4_notify_daemon() may block */
+ /* autofs4_notify_daemon() may block; it will unlock ->wq_mutex */
autofs4_notify_daemon(sbi, wq, type);
} else {
wq->wait_ctr++;
- mutex_unlock(&sbi->wq_mutex);
- kfree(qstr.name);
DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
(unsigned long) wq->wait_queue_token, wq->name.len,
wq->name.name, notify);
+ mutex_unlock(&sbi->wq_mutex);
+ kfree(qstr.name);
}
/*
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 21:58:57 +0000