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Diffstat (limited to 'fs')
-rw-r--r--fs/fcntl.c166
-rw-r--r--fs/file_table.c14
-rw-r--r--fs/internal.h1
-rw-r--r--fs/locks.c6
-rw-r--r--fs/notify/dnotify/dnotify.c6
5 files changed, 152 insertions, 41 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 300e5d9ad913..0587a0e221a6 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -33,6 +33,8 @@
#include <asm/siginfo.h>
#include <linux/uaccess.h>
+#include "internal.h"
+
#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
static int setfl(int fd, struct file * filp, unsigned int arg)
@@ -87,22 +89,64 @@ static int setfl(int fd, struct file * filp, unsigned int arg)
return error;
}
+/*
+ * Allocate an file->f_owner struct if it doesn't exist, handling racing
+ * allocations correctly.
+ */
+int file_f_owner_allocate(struct file *file)
+{
+ struct fown_struct *f_owner;
+
+ f_owner = file_f_owner(file);
+ if (f_owner)
+ return 0;
+
+ f_owner = kzalloc(sizeof(struct fown_struct), GFP_KERNEL);
+ if (!f_owner)
+ return -ENOMEM;
+
+ rwlock_init(&f_owner->lock);
+ f_owner->file = file;
+ /* If someone else raced us, drop our allocation. */
+ if (unlikely(cmpxchg(&file->f_owner, NULL, f_owner)))
+ kfree(f_owner);
+ return 0;
+}
+EXPORT_SYMBOL(file_f_owner_allocate);
+
+void file_f_owner_release(struct file *file)
+{
+ struct fown_struct *f_owner;
+
+ f_owner = file_f_owner(file);
+ if (f_owner) {
+ put_pid(f_owner->pid);
+ kfree(f_owner);
+ }
+}
+
static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
int force)
{
- write_lock_irq(&filp->f_owner.lock);
- if (force || !filp->f_owner.pid) {
- put_pid(filp->f_owner.pid);
- filp->f_owner.pid = get_pid(pid);
- filp->f_owner.pid_type = type;
+ struct fown_struct *f_owner;
+
+ f_owner = file_f_owner(filp);
+ if (WARN_ON_ONCE(!f_owner))
+ return;
+
+ write_lock_irq(&f_owner->lock);
+ if (force || !f_owner->pid) {
+ put_pid(f_owner->pid);
+ f_owner->pid = get_pid(pid);
+ f_owner->pid_type = type;
if (pid) {
const struct cred *cred = current_cred();
- filp->f_owner.uid = cred->uid;
- filp->f_owner.euid = cred->euid;
+ f_owner->uid = cred->uid;
+ f_owner->euid = cred->euid;
}
}
- write_unlock_irq(&filp->f_owner.lock);
+ write_unlock_irq(&f_owner->lock);
}
void __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
@@ -119,6 +163,8 @@ int f_setown(struct file *filp, int who, int force)
struct pid *pid = NULL;
int ret = 0;
+ might_sleep();
+
type = PIDTYPE_TGID;
if (who < 0) {
/* avoid overflow below */
@@ -129,6 +175,10 @@ int f_setown(struct file *filp, int who, int force)
who = -who;
}
+ ret = file_f_owner_allocate(filp);
+ if (ret)
+ return ret;
+
rcu_read_lock();
if (who) {
pid = find_vpid(who);
@@ -152,16 +202,21 @@ void f_delown(struct file *filp)
pid_t f_getown(struct file *filp)
{
pid_t pid = 0;
+ struct fown_struct *f_owner;
+
+ f_owner = file_f_owner(filp);
+ if (!f_owner)
+ return pid;
- read_lock_irq(&filp->f_owner.lock);
+ read_lock_irq(&f_owner->lock);
rcu_read_lock();
- if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) {
- pid = pid_vnr(filp->f_owner.pid);
- if (filp->f_owner.pid_type == PIDTYPE_PGID)
+ if (pid_task(f_owner->pid, f_owner->pid_type)) {
+ pid = pid_vnr(f_owner->pid);
+ if (f_owner->pid_type == PIDTYPE_PGID)
pid = -pid;
}
rcu_read_unlock();
- read_unlock_irq(&filp->f_owner.lock);
+ read_unlock_irq(&f_owner->lock);
return pid;
}
@@ -194,6 +249,10 @@ static int f_setown_ex(struct file *filp, unsigned long arg)
return -EINVAL;
}
+ ret = file_f_owner_allocate(filp);
+ if (ret)
+ return ret;
+
rcu_read_lock();
pid = find_vpid(owner.pid);
if (owner.pid && !pid)
@@ -210,13 +269,20 @@ static int f_getown_ex(struct file *filp, unsigned long arg)
struct f_owner_ex __user *owner_p = (void __user *)arg;
struct f_owner_ex owner = {};
int ret = 0;
+ struct fown_struct *f_owner;
+ enum pid_type pid_type = PIDTYPE_PID;
- read_lock_irq(&filp->f_owner.lock);
- rcu_read_lock();
- if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type))
- owner.pid = pid_vnr(filp->f_owner.pid);
- rcu_read_unlock();
- switch (filp->f_owner.pid_type) {
+ f_owner = file_f_owner(filp);
+ if (f_owner) {
+ read_lock_irq(&f_owner->lock);
+ rcu_read_lock();
+ if (pid_task(f_owner->pid, f_owner->pid_type))
+ owner.pid = pid_vnr(f_owner->pid);
+ rcu_read_unlock();
+ pid_type = f_owner->pid_type;
+ }
+
+ switch (pid_type) {
case PIDTYPE_PID:
owner.type = F_OWNER_TID;
break;
@@ -234,7 +300,8 @@ static int f_getown_ex(struct file *filp, unsigned long arg)
ret = -EINVAL;
break;
}
- read_unlock_irq(&filp->f_owner.lock);
+ if (f_owner)
+ read_unlock_irq(&f_owner->lock);
if (!ret) {
ret = copy_to_user(owner_p, &owner, sizeof(owner));
@@ -248,14 +315,18 @@ static int f_getown_ex(struct file *filp, unsigned long arg)
static int f_getowner_uids(struct file *filp, unsigned long arg)
{
struct user_namespace *user_ns = current_user_ns();
+ struct fown_struct *f_owner;
uid_t __user *dst = (void __user *)arg;
- uid_t src[2];
+ uid_t src[2] = {0, 0};
int err;
- read_lock_irq(&filp->f_owner.lock);
- src[0] = from_kuid(user_ns, filp->f_owner.uid);
- src[1] = from_kuid(user_ns, filp->f_owner.euid);
- read_unlock_irq(&filp->f_owner.lock);
+ f_owner = file_f_owner(filp);
+ if (f_owner) {
+ read_lock_irq(&f_owner->lock);
+ src[0] = from_kuid(user_ns, f_owner->uid);
+ src[1] = from_kuid(user_ns, f_owner->euid);
+ read_unlock_irq(&f_owner->lock);
+ }
err = put_user(src[0], &dst[0]);
err |= put_user(src[1], &dst[1]);
@@ -343,6 +414,30 @@ static long f_dupfd_query(int fd, struct file *filp)
return f.file == filp;
}
+static int f_owner_sig(struct file *filp, int signum, bool setsig)
+{
+ int ret = 0;
+ struct fown_struct *f_owner;
+
+ might_sleep();
+
+ if (setsig) {
+ if (!valid_signal(signum))
+ return -EINVAL;
+
+ ret = file_f_owner_allocate(filp);
+ if (ret)
+ return ret;
+ }
+
+ f_owner = file_f_owner(filp);
+ if (setsig)
+ f_owner->signum = signum;
+ else if (f_owner)
+ ret = f_owner->signum;
+ return ret;
+}
+
static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
struct file *filp)
{
@@ -421,15 +516,10 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
err = f_getowner_uids(filp, arg);
break;
case F_GETSIG:
- err = filp->f_owner.signum;
+ err = f_owner_sig(filp, 0, false);
break;
case F_SETSIG:
- /* arg == 0 restores default behaviour. */
- if (!valid_signal(argi)) {
- break;
- }
- err = 0;
- filp->f_owner.signum = argi;
+ err = f_owner_sig(filp, argi, true);
break;
case F_GETLEASE:
err = fcntl_getlease(filp);
@@ -844,14 +934,19 @@ static void send_sigurg_to_task(struct task_struct *p,
do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, type);
}
-int send_sigurg(struct fown_struct *fown)
+int send_sigurg(struct file *file)
{
+ struct fown_struct *fown;
struct task_struct *p;
enum pid_type type;
struct pid *pid;
unsigned long flags;
int ret = 0;
+ fown = file_f_owner(file);
+ if (!fown)
+ return 0;
+
read_lock_irqsave(&fown->lock, flags);
type = fown->pid_type;
@@ -1027,13 +1122,16 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band)
}
read_lock_irqsave(&fa->fa_lock, flags);
if (fa->fa_file) {
- fown = &fa->fa_file->f_owner;
+ fown = file_f_owner(fa->fa_file);
+ if (!fown)
+ goto next;
/* Don't send SIGURG to processes which have not set a
queued signum: SIGURG has its own default signalling
mechanism. */
if (!(sig == SIGURG && fown->signum == 0))
send_sigio(fown, fa->fa_fd, band);
}
+next:
read_unlock_irqrestore(&fa->fa_lock, flags);
fa = rcu_dereference(fa->fa_next);
}
diff --git a/fs/file_table.c b/fs/file_table.c
index ca7843dde56d..861c03608e83 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -155,7 +155,6 @@ static int init_file(struct file *f, int flags, const struct cred *cred)
return error;
}
- rwlock_init(&f->f_owner.lock);
spin_lock_init(&f->f_lock);
mutex_init(&f->f_pos_lock);
f->f_flags = flags;
@@ -425,7 +424,7 @@ static void __fput(struct file *file)
cdev_put(inode->i_cdev);
}
fops_put(file->f_op);
- put_pid(file->f_owner.pid);
+ file_f_owner_release(file);
put_file_access(file);
dput(dentry);
if (unlikely(mode & FMODE_NEED_UNMOUNT))
@@ -512,9 +511,14 @@ EXPORT_SYMBOL(__fput_sync);
void __init files_init(void)
{
- filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
- SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN |
- SLAB_PANIC | SLAB_ACCOUNT, NULL);
+ struct kmem_cache_args args = {
+ .use_freeptr_offset = true,
+ .freeptr_offset = offsetof(struct file, f_freeptr),
+ };
+
+ filp_cachep = kmem_cache_create("filp", sizeof(struct file), &args,
+ SLAB_HWCACHE_ALIGN | SLAB_PANIC |
+ SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU);
percpu_counter_init(&nr_files, 0, GFP_KERNEL);
}
diff --git a/fs/internal.h b/fs/internal.h
index cdd73209eecb..8c1b7acbbe8f 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -337,3 +337,4 @@ static inline bool path_mounted(const struct path *path)
{
return path->mnt->mnt_root == path->dentry;
}
+void file_f_owner_release(struct file *file);
diff --git a/fs/locks.c b/fs/locks.c
index e45cad40f8b6..b51b1c395ce6 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1451,7 +1451,7 @@ int lease_modify(struct file_lease *fl, int arg, struct list_head *dispose)
struct file *filp = fl->c.flc_file;
f_delown(filp);
- filp->f_owner.signum = 0;
+ file_f_owner(filp)->signum = 0;
fasync_helper(0, fl->c.flc_file, 0, &fl->fl_fasync);
if (fl->fl_fasync != NULL) {
printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync);
@@ -1783,6 +1783,10 @@ generic_add_lease(struct file *filp, int arg, struct file_lease **flp, void **pr
lease = *flp;
trace_generic_add_lease(inode, lease);
+ error = file_f_owner_allocate(filp);
+ if (error)
+ return error;
+
/* Note that arg is never F_UNLCK here */
ctx = locks_get_lock_context(inode, arg);
if (!ctx)
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index f3669403fabf..46440fbb8662 100644
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -110,7 +110,7 @@ static int dnotify_handle_event(struct fsnotify_mark *inode_mark, u32 mask,
prev = &dn->dn_next;
continue;
}
- fown = &dn->dn_filp->f_owner;
+ fown = file_f_owner(dn->dn_filp);
send_sigio(fown, dn->dn_fd, POLL_MSG);
if (dn->dn_mask & FS_DN_MULTISHOT)
prev = &dn->dn_next;
@@ -316,6 +316,10 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned int arg)
goto out_err;
}
+ error = file_f_owner_allocate(filp);
+ if (error)
+ goto out_err;
+
/* set up the new_fsn_mark and new_dn_mark */
new_fsn_mark = &new_dn_mark->fsn_mark;
fsnotify_init_mark(new_fsn_mark, dnotify_group);
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