pca953x: support GPIOLIB GPIO naming

[safe/jmp/linux-2.6] / fs / fcntl.c

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 04df857..a040b76 100644 (file)
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -117,11 +117,13 @@ SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd)
 {
        if (unlikely(newfd == oldfd)) { /* corner case */
                struct files_struct *files = current->files;
+               int retval = oldfd;
+
                rcu_read_lock();
                if (!fcheck_files(files, oldfd))
-                       oldfd = -EBADF;
+                       retval = -EBADF;
                rcu_read_unlock();
-               return oldfd;
+               return retval;
        }
        return sys_dup3(oldfd, newfd, 0);
 }
@@ -141,7 +143,7 @@ SYSCALL_DEFINE1(dup, unsigned int, fildes)
        return ret;
 }
 
-#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME)
+#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
 
 static int setfl(int fd, struct file * filp, unsigned long arg)
 {
@@ -177,36 +179,38 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
                return error;
 
        /*
-        * We still need a lock here for now to keep multiple FASYNC calls
-        * from racing with each other.
+        * ->fasync() is responsible for setting the FASYNC bit.
         */
-       lock_kernel();
-       if ((arg ^ filp->f_flags) & FASYNC) {
-               if (filp->f_op && filp->f_op->fasync) {
-                       error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
-                       if (error < 0)
-                               goto out;
-               }
+       if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op &&
+                       filp->f_op->fasync) {
+               error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
+               if (error < 0)
+                       goto out;
+               if (error > 0)
+                       error = 0;
        }
-
        spin_lock(&filp->f_lock);
        filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
        spin_unlock(&filp->f_lock);
+
  out:
-       unlock_kernel();
        return error;
 }
 
 static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
-                     uid_t uid, uid_t euid, int force)
+                     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;
-               filp->f_owner.uid = uid;
-               filp->f_owner.euid = euid;
+
+               if (pid) {
+                       const struct cred *cred = current_cred();
+                       filp->f_owner.uid = cred->uid;
+                       filp->f_owner.euid = cred->euid;
+               }
        }
        write_unlock_irq(&filp->f_owner.lock);
 }
@@ -214,14 +218,13 @@ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type,
 int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
                int force)
 {
-       const struct cred *cred = current_cred();
        int err;
-       
+
        err = security_file_set_fowner(filp);
        if (err)
                return err;
 
-       f_modown(filp, pid, type, cred->uid, cred->euid, force);
+       f_modown(filp, pid, type, force);
        return 0;
 }
 EXPORT_SYMBOL(__f_setown);
@@ -247,7 +250,7 @@ EXPORT_SYMBOL(f_setown);
 
 void f_delown(struct file *filp)
 {
-       f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1);
+       f_modown(filp, NULL, PIDTYPE_PID, 1);
 }
 
 pid_t f_getown(struct file *filp)
@@ -425,14 +428,20 @@ static inline int sigio_perm(struct task_struct *p,
 }
 
 static void send_sigio_to_task(struct task_struct *p,
-                              struct fown_struct *fown, 
+                              struct fown_struct *fown,
                               int fd,
                               int reason)
 {
-       if (!sigio_perm(p, fown, fown->signum))
+       /*
+        * F_SETSIG can change ->signum lockless in parallel, make
+        * sure we read it once and use the same value throughout.
+        */
+       int signum = ACCESS_ONCE(fown->signum);
+
+       if (!sigio_perm(p, fown, signum))
                return;
 
-       switch (fown->signum) {
+       switch (signum) {
                siginfo_t si;
                default:
                        /* Queue a rt signal with the appropriate fd as its
@@ -441,7 +450,7 @@ static void send_sigio_to_task(struct task_struct *p,
                           delivered even if we can't queue.  Failure to
                           queue in this case _should_ be reported; we fall
                           back to SIGIO in that case. --sct */
-                       si.si_signo = fown->signum;
+                       si.si_signo = signum;
                        si.si_errno = 0;
                        si.si_code  = reason;
                        /* Make sure we are called with one of the POLL_*
@@ -453,7 +462,7 @@ static void send_sigio_to_task(struct task_struct *p,
                        else
                                si.si_band = band_table[reason - POLL_IN];
                        si.si_fd    = fd;
-                       if (!group_send_sig_info(fown->signum, &si, p))
+                       if (!group_send_sig_info(signum, &si, p))
                                break;
                /* fall-through: fall back on the old plain SIGIO signal */
                case 0:
@@ -518,7 +527,7 @@ static DEFINE_RWLOCK(fasync_lock);
 static struct kmem_cache *fasync_cache __read_mostly;
 
 /*
- * fasync_helper() is used by some character device drivers (mainly mice)
+ * fasync_helper() is used by almost all character device drivers
  * to set up the fasync queue. It returns negative on error, 0 if it did
  * no changes and positive if it added/deleted the entry.
  */
@@ -533,6 +542,12 @@ int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fap
                if (!new)
                        return -ENOMEM;
        }
+
+       /*
+        * We need to take f_lock first since it's not an IRQ-safe
+        * lock.
+        */
+       spin_lock(&filp->f_lock);
        write_lock_irq(&fasync_lock);
        for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
                if (fa->fa_file == filp) {
@@ -557,7 +572,12 @@ int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fap
                result = 1;
        }
 out:
+       if (on)
+               filp->f_flags |= FASYNC;
+       else
+               filp->f_flags &= ~FASYNC;
        write_unlock_irq(&fasync_lock);
+       spin_unlock(&filp->f_lock);
        return result;
 }