mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-04 23:26:40 +07:00
ede1bf0dcf
A patchset to remove support for passing pre-allocated struct seq_file to
seq_open(). Such feature is undocumented and prone to error.
In particular, if seq_release() is used in release handler, it will
kfree() a pointer which was not allocated by seq_open().
So this patchset drops support for pre-allocated struct seq_file: it's
only of use in proc_namespace.c and can be easily replaced by using
seq_open_private()/seq_release_private().
Additionally, it documents the use of file->private_data to hold pointer
to struct seq_file by seq_open().
This patch (of 3):
Since patch described below, from v2.6.15-rc1, seq_open() could use a
struct seq_file already allocated by the caller if the pointer to the
structure is stored in file->private_data before calling the function.
Commit 1abe77b0fc
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon Nov 7 17:15:34 2005 -0500
[PATCH] allow callers of seq_open do allocation themselves
Allow caller of seq_open() to kmalloc() seq_file + whatever else they
want and set ->private_data to it. seq_open() will then abstain from
doing allocation itself.
Such behavior is only used by mounts_open_common().
In order to drop support for such uncommon feature, proc_mounts is
converted to use seq_open_private(), which take care of allocating the
proc_mounts structure, making it available through ->private in struct
seq_file.
Conversely, proc_mounts is converted to use seq_release_private(), in
order to release the private structure allocated by seq_open_private().
Then, ->private is used directly instead of proc_mounts() macro to access
to the proc_mounts structure.
Link: http://lkml.kernel.org/r/cover.1433193673.git.ydroneaud@opteya.com
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
139 lines
3.5 KiB
C
139 lines
3.5 KiB
C
#include <linux/mount.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/ns_common.h>
|
|
#include <linux/fs_pin.h>
|
|
|
|
struct mnt_namespace {
|
|
atomic_t count;
|
|
struct ns_common ns;
|
|
struct mount * root;
|
|
struct list_head list;
|
|
struct user_namespace *user_ns;
|
|
u64 seq; /* Sequence number to prevent loops */
|
|
wait_queue_head_t poll;
|
|
u64 event;
|
|
};
|
|
|
|
struct mnt_pcp {
|
|
int mnt_count;
|
|
int mnt_writers;
|
|
};
|
|
|
|
struct mountpoint {
|
|
struct hlist_node m_hash;
|
|
struct dentry *m_dentry;
|
|
struct hlist_head m_list;
|
|
int m_count;
|
|
};
|
|
|
|
struct mount {
|
|
struct hlist_node mnt_hash;
|
|
struct mount *mnt_parent;
|
|
struct dentry *mnt_mountpoint;
|
|
struct vfsmount mnt;
|
|
union {
|
|
struct rcu_head mnt_rcu;
|
|
struct llist_node mnt_llist;
|
|
};
|
|
#ifdef CONFIG_SMP
|
|
struct mnt_pcp __percpu *mnt_pcp;
|
|
#else
|
|
int mnt_count;
|
|
int mnt_writers;
|
|
#endif
|
|
struct list_head mnt_mounts; /* list of children, anchored here */
|
|
struct list_head mnt_child; /* and going through their mnt_child */
|
|
struct list_head mnt_instance; /* mount instance on sb->s_mounts */
|
|
const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
|
|
struct list_head mnt_list;
|
|
struct list_head mnt_expire; /* link in fs-specific expiry list */
|
|
struct list_head mnt_share; /* circular list of shared mounts */
|
|
struct list_head mnt_slave_list;/* list of slave mounts */
|
|
struct list_head mnt_slave; /* slave list entry */
|
|
struct mount *mnt_master; /* slave is on master->mnt_slave_list */
|
|
struct mnt_namespace *mnt_ns; /* containing namespace */
|
|
struct mountpoint *mnt_mp; /* where is it mounted */
|
|
struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
|
|
#ifdef CONFIG_FSNOTIFY
|
|
struct hlist_head mnt_fsnotify_marks;
|
|
__u32 mnt_fsnotify_mask;
|
|
#endif
|
|
int mnt_id; /* mount identifier */
|
|
int mnt_group_id; /* peer group identifier */
|
|
int mnt_expiry_mark; /* true if marked for expiry */
|
|
struct hlist_head mnt_pins;
|
|
struct fs_pin mnt_umount;
|
|
struct dentry *mnt_ex_mountpoint;
|
|
};
|
|
|
|
#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
|
|
|
|
static inline struct mount *real_mount(struct vfsmount *mnt)
|
|
{
|
|
return container_of(mnt, struct mount, mnt);
|
|
}
|
|
|
|
static inline int mnt_has_parent(struct mount *mnt)
|
|
{
|
|
return mnt != mnt->mnt_parent;
|
|
}
|
|
|
|
static inline int is_mounted(struct vfsmount *mnt)
|
|
{
|
|
/* neither detached nor internal? */
|
|
return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
|
|
}
|
|
|
|
extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
|
|
extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
|
|
|
|
extern int __legitimize_mnt(struct vfsmount *, unsigned);
|
|
extern bool legitimize_mnt(struct vfsmount *, unsigned);
|
|
|
|
extern void __detach_mounts(struct dentry *dentry);
|
|
|
|
static inline void detach_mounts(struct dentry *dentry)
|
|
{
|
|
if (!d_mountpoint(dentry))
|
|
return;
|
|
__detach_mounts(dentry);
|
|
}
|
|
|
|
static inline void get_mnt_ns(struct mnt_namespace *ns)
|
|
{
|
|
atomic_inc(&ns->count);
|
|
}
|
|
|
|
extern seqlock_t mount_lock;
|
|
|
|
static inline void lock_mount_hash(void)
|
|
{
|
|
write_seqlock(&mount_lock);
|
|
}
|
|
|
|
static inline void unlock_mount_hash(void)
|
|
{
|
|
write_sequnlock(&mount_lock);
|
|
}
|
|
|
|
struct proc_mounts {
|
|
struct mnt_namespace *ns;
|
|
struct path root;
|
|
int (*show)(struct seq_file *, struct vfsmount *);
|
|
void *cached_mount;
|
|
u64 cached_event;
|
|
loff_t cached_index;
|
|
};
|
|
|
|
extern const struct seq_operations mounts_op;
|
|
|
|
extern bool __is_local_mountpoint(struct dentry *dentry);
|
|
static inline bool is_local_mountpoint(struct dentry *dentry)
|
|
{
|
|
if (!d_mountpoint(dentry))
|
|
return false;
|
|
|
|
return __is_local_mountpoint(dentry);
|
|
}
|