[PATCH] x86-64: Don't include config.h in asm/timex.h

[pandora-kernel.git] / fs / fcntl.c

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 6fbc9d8..863b46e 100644 (file)
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -16,6 +16,7 @@
 #include <linux/security.h>
 #include <linux/ptrace.h>
 #include <linux/signal.h>
+#include <linux/rcupdate.h>
 
 #include <asm/poll.h>
 #include <asm/siginfo.h>
@@ -24,21 +25,25 @@
 void fastcall set_close_on_exec(unsigned int fd, int flag)
 {
        struct files_struct *files = current->files;
+       struct fdtable *fdt;
        spin_lock(&files->file_lock);
+       fdt = files_fdtable(files);
        if (flag)
-               FD_SET(fd, files->close_on_exec);
+               FD_SET(fd, fdt->close_on_exec);
        else
-               FD_CLR(fd, files->close_on_exec);
+               FD_CLR(fd, fdt->close_on_exec);
        spin_unlock(&files->file_lock);
 }
 
 static inline int get_close_on_exec(unsigned int fd)
 {
        struct files_struct *files = current->files;
+       struct fdtable *fdt;
        int res;
-       spin_lock(&files->file_lock);
-       res = FD_ISSET(fd, files->close_on_exec);
-       spin_unlock(&files->file_lock);
+       rcu_read_lock();
+       fdt = files_fdtable(files);
+       res = FD_ISSET(fd, fdt->close_on_exec);
+       rcu_read_unlock();
        return res;
 }
 
@@ -54,24 +59,26 @@ static int locate_fd(struct files_struct *files,
        unsigned int newfd;
        unsigned int start;
        int error;
+       struct fdtable *fdt;
 
        error = -EINVAL;
        if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
                goto out;
 
 repeat:
+       fdt = files_fdtable(files);
        /*
         * Someone might have closed fd's in the range
-        * orig_start..files->next_fd
+        * orig_start..fdt->next_fd
         */
        start = orig_start;
-       if (start < files->next_fd)
-               start = files->next_fd;
+       if (start < fdt->next_fd)
+               start = fdt->next_fd;
 
        newfd = start;
-       if (start < files->max_fdset) {
-               newfd = find_next_zero_bit(files->open_fds->fds_bits,
-                       files->max_fdset, start);
+       if (start < fdt->max_fdset) {
+               newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
+                       fdt->max_fdset, start);
        }
        
        error = -EMFILE;
@@ -89,9 +96,15 @@ repeat:
        if (error)
                goto repeat;
 
-       if (start <= files->next_fd)
-               files->next_fd = newfd + 1;
-       
+       /*
+        * We reacquired files_lock, so we are safe as long as
+        * we reacquire the fdtable pointer and use it while holding
+        * the lock, no one can free it during that time.
+        */
+       fdt = files_fdtable(files);
+       if (start <= fdt->next_fd)
+               fdt->next_fd = newfd + 1;
+
        error = newfd;
        
 out:
@@ -101,13 +114,16 @@ out:
 static int dupfd(struct file *file, unsigned int start)
 {
        struct files_struct * files = current->files;
+       struct fdtable *fdt;
        int fd;
 
        spin_lock(&files->file_lock);
        fd = locate_fd(files, file, start);
        if (fd >= 0) {
-               FD_SET(fd, files->open_fds);
-               FD_CLR(fd, files->close_on_exec);
+               /* locate_fd() may have expanded fdtable, load the ptr */
+               fdt = files_fdtable(files);
+               FD_SET(fd, fdt->open_fds);
+               FD_CLR(fd, fdt->close_on_exec);
                spin_unlock(&files->file_lock);
                fd_install(fd, file);
        } else {
@@ -123,6 +139,7 @@ asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
        int err = -EBADF;
        struct file * file, *tofree;
        struct files_struct * files = current->files;
+       struct fdtable *fdt;
 
        spin_lock(&files->file_lock);
        if (!(file = fcheck(oldfd)))
@@ -148,13 +165,14 @@ asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
 
        /* Yes. It's a race. In user space. Nothing sane to do */
        err = -EBUSY;
-       tofree = files->fd[newfd];
-       if (!tofree && FD_ISSET(newfd, files->open_fds))
+       fdt = files_fdtable(files);
+       tofree = fdt->fd[newfd];
+       if (!tofree && FD_ISSET(newfd, fdt->open_fds))
                goto out_fput;
 
-       files->fd[newfd] = file;
-       FD_SET(newfd, files->open_fds);
-       FD_CLR(newfd, files->close_on_exec);
+       rcu_assign_pointer(fdt->fd[newfd], file);
+       FD_SET(newfd, fdt->open_fds);
+       FD_CLR(newfd, fdt->close_on_exec);
        spin_unlock(&files->file_lock);
 
        if (tofree)