Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

[linux-2.6] / fs / open.c

diff --git a/fs/open.c b/fs/open.c
index b6542516a0cab8acd88c3f95f3db6998add7b579..f0d90cf0495c490316d427e309c38695ceb4e005 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -24,6 +24,7 @@
 #include <linux/personality.h>
 #include <linux/pagemap.h>
 #include <linux/syscalls.h>
+#include <linux/rcupdate.h>
 
 #include <asm/unistd.h>
 
@@ -737,52 +738,15 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
        return error;
 }
 
-/*
- * Note that while the flag value (low two bits) for sys_open means:
- *     00 - read-only
- *     01 - write-only
- *     10 - read-write
- *     11 - special
- * it is changed into
- *     00 - no permissions needed
- *     01 - read-permission
- *     10 - write-permission
- *     11 - read-write
- * for the internal routines (ie open_namei()/follow_link() etc). 00 is
- * used by symlinks.
- */
-struct file *filp_open(const char * filename, int flags, int mode)
-{
-       int namei_flags, error;
-       struct nameidata nd;
-
-       namei_flags = flags;
-       if ((namei_flags+1) & O_ACCMODE)
-               namei_flags++;
-       if (namei_flags & O_TRUNC)
-               namei_flags |= 2;
-
-       error = open_namei(filename, namei_flags, mode, &nd);
-       if (!error)
-               return dentry_open(nd.dentry, nd.mnt, flags);
-
-       return ERR_PTR(error);
-}
-
-EXPORT_SYMBOL(filp_open);
-
-struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
+static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+                                       int flags, struct file *f)
 {
-       struct file * f;
        struct inode *inode;
        int error;
 
-       error = -ENFILE;
-       f = get_empty_filp();
-       if (!f)
-               goto cleanup_dentry;
        f->f_flags = flags;
-       f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
+       f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK |
+                               FMODE_PREAD | FMODE_PWRITE;
        inode = dentry->d_inode;
        if (f->f_mode & FMODE_WRITE) {
                error = get_write_access(inode);
@@ -827,12 +791,63 @@ cleanup_all:
        f->f_vfsmnt = NULL;
 cleanup_file:
        put_filp(f);
-cleanup_dentry:
        dput(dentry);
        mntput(mnt);
        return ERR_PTR(error);
 }
 
+/*
+ * Note that while the flag value (low two bits) for sys_open means:
+ *     00 - read-only
+ *     01 - write-only
+ *     10 - read-write
+ *     11 - special
+ * it is changed into
+ *     00 - no permissions needed
+ *     01 - read-permission
+ *     10 - write-permission
+ *     11 - read-write
+ * for the internal routines (ie open_namei()/follow_link() etc). 00 is
+ * used by symlinks.
+ */
+struct file *filp_open(const char * filename, int flags, int mode)
+{
+       int namei_flags, error;
+       struct nameidata nd;
+       struct file *f;
+
+       namei_flags = flags;
+       if ((namei_flags+1) & O_ACCMODE)
+               namei_flags++;
+       if (namei_flags & O_TRUNC)
+               namei_flags |= 2;
+
+       error = -ENFILE;
+       f = get_empty_filp();
+       if (f == NULL)
+               return ERR_PTR(error);
+
+       error = open_namei(filename, namei_flags, mode, &nd);
+       if (!error)
+               return __dentry_open(nd.dentry, nd.mnt, flags, f);
+
+       put_filp(f);
+       return ERR_PTR(error);
+}
+EXPORT_SYMBOL(filp_open);
+
+struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
+{
+       int error;
+       struct file *f;
+
+       error = -ENFILE;
+       f = get_empty_filp();
+       if (f == NULL)
+               return ERR_PTR(error);
+
+       return __dentry_open(dentry, mnt, flags, f);
+}
 EXPORT_SYMBOL(dentry_open);
 
 /*
@@ -930,9 +945,8 @@ void fastcall fd_install(unsigned int fd, struct file * file)
        struct fdtable *fdt;
        spin_lock(&files->file_lock);
        fdt = files_fdtable(files);
-       if (unlikely(fdt->fd[fd] != NULL))
-               BUG();
-       fdt->fd[fd] = file;
+       BUG_ON(fdt->fd[fd] != NULL);
+       rcu_assign_pointer(fdt->fd[fd], file);
        spin_unlock(&files->file_lock);
 }
 
@@ -1024,7 +1038,7 @@ asmlinkage long sys_close(unsigned int fd)
        filp = fdt->fd[fd];
        if (!filp)
                goto out_unlock;
-       fdt->fd[fd] = NULL;
+       rcu_assign_pointer(fdt->fd[fd], NULL);
        FD_CLR(fd, fdt->close_on_exec);
        __put_unused_fd(files, fd);
        spin_unlock(&files->file_lock);