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-rw-r--r--fs/internal.h3
-rw-r--r--fs/libfs.c15
-rw-r--r--fs/nsfs.c7
-rw-r--r--fs/pidfs.c59
-rw-r--r--include/linux/pid.h1
-rw-r--r--include/linux/pidfs.h1
-rw-r--r--kernel/pid.c1
7 files changed, 59 insertions, 28 deletions
diff --git a/fs/internal.h b/fs/internal.h
index cfddaec6fbf6..a34531bcad6e 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -312,4 +312,5 @@ struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
void mnt_idmap_put(struct mnt_idmap *idmap);
int path_from_stashed(struct dentry **stashed, unsigned long ino,
struct vfsmount *mnt, const struct file_operations *fops,
- void *data, struct path *path);
+ const struct inode_operations *iops, void *data,
+ struct path *path);
diff --git a/fs/libfs.c b/fs/libfs.c
index 2a55e87e1439..2acba9d53756 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -23,6 +23,7 @@
#include <linux/fsnotify.h>
#include <linux/unicode.h>
#include <linux/fscrypt.h>
+#include <linux/pidfs.h>
#include <linux/uaccess.h>
@@ -1990,6 +1991,7 @@ static inline struct dentry *get_stashed_dentry(struct dentry *stashed)
static struct dentry *stash_dentry(struct dentry **stashed, unsigned long ino,
struct super_block *sb,
const struct file_operations *fops,
+ const struct inode_operations *iops,
void *data)
{
struct dentry *dentry;
@@ -2007,8 +2009,13 @@ static struct dentry *stash_dentry(struct dentry **stashed, unsigned long ino,
inode->i_ino = ino;
inode->i_flags |= S_IMMUTABLE;
+ if (is_pidfs_sb(sb))
+ inode->i_flags |= S_PRIVATE;
inode->i_mode = S_IFREG | S_IRUGO;
- inode->i_fop = fops;
+ if (iops)
+ inode->i_op = iops;
+ if (fops)
+ inode->i_fop = fops;
inode->i_private = data;
simple_inode_init_ts(inode);
@@ -2030,6 +2037,7 @@ static struct dentry *stash_dentry(struct dentry **stashed, unsigned long ino,
* @stashed: where to retrieve or stash dentry
* @ino: inode number to use
* @mnt: mnt of the filesystems to use
+ * @iops: inode operations to use
* @fops: file operations to use
* @data: data to store in inode->i_private
* @path: path to create
@@ -2048,7 +2056,8 @@ static struct dentry *stash_dentry(struct dentry **stashed, unsigned long ino,
*/
int path_from_stashed(struct dentry **stashed, unsigned long ino,
struct vfsmount *mnt, const struct file_operations *fops,
- void *data, struct path *path)
+ const struct inode_operations *iops, void *data,
+ struct path *path)
{
struct dentry *dentry;
int ret = 0;
@@ -2057,7 +2066,7 @@ int path_from_stashed(struct dentry **stashed, unsigned long ino,
if (dentry)
goto out_path;
- dentry = stash_dentry(stashed, ino, mnt->mnt_sb, fops, data);
+ dentry = stash_dentry(stashed, ino, mnt->mnt_sb, fops, iops, data);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
ret = 1;
diff --git a/fs/nsfs.c b/fs/nsfs.c
index 39dc2604bec0..e2da645c3d02 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -67,7 +67,7 @@ int ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
if (!ns)
return -ENOENT;
ret = path_from_stashed(&ns->stashed, ns->inum, nsfs_mnt,
- &ns_file_operations, ns, path);
+ &ns_file_operations, NULL, ns, path);
if (ret <= 0 && ret != -EAGAIN)
ns->ops->put(ns);
} while (ret == -EAGAIN);
@@ -122,8 +122,9 @@ int open_related_ns(struct ns_common *ns,
return PTR_ERR(relative);
}
- err = path_from_stashed(&relative->stashed, relative->inum, nsfs_mnt,
- &ns_file_operations, relative, &path);
+ err = path_from_stashed(&relative->stashed, relative->inum,
+ nsfs_mnt, &ns_file_operations, NULL,
+ relative, &path);
if (err <= 0 && err != -EAGAIN)
relative->ops->put(relative);
} while (err == -EAGAIN);
diff --git a/fs/pidfs.c b/fs/pidfs.c
index 6c3f010074af..cf606f15def5 100644
--- a/fs/pidfs.c
+++ b/fs/pidfs.c
@@ -14,6 +14,8 @@
#include <linux/seq_file.h>
#include <uapi/linux/pidfd.h>
+#include "internal.h"
+
static int pidfd_release(struct inode *inode, struct file *file)
{
#ifndef CONFIG_FS_PID
@@ -186,9 +188,21 @@ static char *pidfs_dname(struct dentry *dentry, char *buffer, int buflen)
d_inode(dentry)->i_ino);
}
+static void pidfs_prune_dentry(struct dentry *dentry)
+{
+ struct inode *inode;
+
+ inode = d_inode(dentry);
+ if (inode) {
+ struct pid *pid = inode->i_private;
+ WRITE_ONCE(pid->stashed, NULL);
+ }
+}
+
static const struct dentry_operations pidfs_dentry_operations = {
.d_delete = always_delete_dentry,
.d_dname = pidfs_dname,
+ .d_prune = pidfs_prune_dentry,
};
static int pidfs_init_fs_context(struct fs_context *fc)
@@ -213,34 +227,28 @@ static struct file_system_type pidfs_type = {
struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags)
{
- struct inode *inode;
struct file *pidfd_file;
+ struct path path;
+ int ret;
- inode = iget_locked(pidfs_sb, pid->ino);
- if (!inode)
- return ERR_PTR(-ENOMEM);
-
- if (inode->i_state & I_NEW) {
+ do {
/*
* Inode numbering for pidfs start at RESERVED_PIDS + 1.
* This avoids collisions with the root inode which is 1
* for pseudo filesystems.
*/
- inode->i_ino = pid->ino;
- inode->i_mode = S_IFREG | S_IRUGO;
- inode->i_op = &pidfs_inode_operations;
- inode->i_fop = &pidfs_file_operations;
- inode->i_flags |= S_IMMUTABLE;
- inode->i_private = get_pid(pid);
- simple_inode_init_ts(inode);
- unlock_new_inode(inode);
- }
-
- pidfd_file = alloc_file_pseudo(inode, pidfs_mnt, "", flags,
- &pidfs_file_operations);
- if (IS_ERR(pidfd_file))
- iput(inode);
-
+ ret = path_from_stashed(&pid->stashed, pid->ino, pidfs_mnt,
+ &pidfs_file_operations,
+ &pidfs_inode_operations, get_pid(pid),
+ &path);
+ if (ret <= 0 && ret != -EAGAIN)
+ put_pid(pid);
+ } while (ret == -EAGAIN);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ pidfd_file = dentry_open(&path, flags, current_cred());
+ path_put(&path);
return pidfd_file;
}
@@ -253,6 +261,11 @@ void __init pidfs_init(void)
pidfs_sb = pidfs_mnt->mnt_sb;
}
+bool is_pidfs_sb(const struct super_block *sb)
+{
+ return sb == pidfs_mnt->mnt_sb;
+}
+
#else /* !CONFIG_FS_PID */
struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags)
@@ -269,4 +282,8 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags)
}
void __init pidfs_init(void) { }
+bool is_pidfs_sb(const struct super_block *sb)
+{
+ return false;
+}
#endif
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 956481128e8d..c79a0efd0258 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -56,6 +56,7 @@ struct pid
unsigned int level;
spinlock_t lock;
#ifdef CONFIG_FS_PID
+ struct dentry *stashed;
unsigned long ino;
#endif
/* lists of tasks that use this pid */
diff --git a/include/linux/pidfs.h b/include/linux/pidfs.h
index 75bdf9807802..40dd325a32a6 100644
--- a/include/linux/pidfs.h
+++ b/include/linux/pidfs.h
@@ -4,5 +4,6 @@
struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags);
void __init pidfs_init(void);
+bool is_pidfs_sb(const struct super_block *sb);
#endif /* _LINUX_PID_FS_H */
diff --git a/kernel/pid.c b/kernel/pid.c
index 581cc34341fd..99a0c5eb24b8 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -281,6 +281,7 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid,
if (!(ns->pid_allocated & PIDNS_ADDING))
goto out_unlock;
#ifdef CONFIG_FS_PID
+ pid->stashed = NULL;
pid->ino = ++pidfs_ino;
#endif
for ( ; upid >= pid->numbers; --upid) {
generated by cgit (git 2.34.1) at 2024-06-15 06:46:44 +0000