lkml.org 
[lkml]   [2007]   [Jun]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[patch 4/8] fdmap v2 - add a new O_NONSEQFD flag to sys_open
This patch introduces a new O_NONSEQFD flag for the sys_open()
system call. Using such flag, the caller can ask the kernel to allocate
the file descriptor inside the non-sequential area.



Signed-off-by: Davide Libenzi <davidel@xmailserver.org>


- Davide


Index: linux-2.6.mod/fs/open.c
===================================================================
--- linux-2.6.mod.orig/fs/open.c 2007-06-06 12:48:03.000000000 -0700
+++ linux-2.6.mod/fs/open.c 2007-06-06 12:48:37.000000000 -0700
@@ -978,6 +978,23 @@
return FDMAP_NONSEQ_BASE + (rndb & ((1U << FDMAP_RANDOM_BITS) - 1));
}

+/**
+ * allocate_fd - Allocates a new file descriptor
+ *
+ * @flags: [in] Flags to control the allocation type and the new descriptor
+ * characteristics
+ *
+ * Returns the newly allocated file descriptor, or a negative value in
+ * case of error.
+ */
+int allocate_fd(unsigned long flags)
+{
+ if (flags & O_NONSEQFD)
+ return alloc_nonseq_fd(current->files, flags);
+ else
+ return get_unused_fd();
+}
+
/*
* Install a file pointer in the fd array.
*
@@ -1011,7 +1028,7 @@
int fd = PTR_ERR(tmp);

if (!IS_ERR(tmp)) {
- fd = get_unused_fd();
+ fd = allocate_fd((unsigned int) flags);
if (fd >= 0) {
struct file *f = do_filp_open(dfd, tmp, flags, mode);
if (IS_ERR(f)) {
Index: linux-2.6.mod/include/asm-generic/fcntl.h
===================================================================
--- linux-2.6.mod.orig/include/asm-generic/fcntl.h 2007-06-06 12:38:27.000000000 -0700
+++ linux-2.6.mod/include/asm-generic/fcntl.h 2007-06-06 12:48:37.000000000 -0700
@@ -48,6 +48,9 @@
#ifndef O_NOATIME
#define O_NOATIME 01000000
#endif
+#ifndef O_NONSEQFD
+#define O_NONSEQFD 02000000
+#endif
#ifndef O_NDELAY
#define O_NDELAY O_NONBLOCK
#endif
Index: linux-2.6.mod/include/linux/file.h
===================================================================
--- linux-2.6.mod.orig/include/linux/file.h 2007-06-06 12:48:28.000000000 -0700
+++ linux-2.6.mod/include/linux/file.h 2007-06-06 12:48:37.000000000 -0700
@@ -85,6 +85,7 @@
extern int __alloc_nonseq_fd(struct files_struct *files, unsigned long flags);
extern int alloc_nonseq_fd(struct files_struct *files, unsigned long flags);
extern unsigned int gen_nonseqfd_base(void);
+extern int allocate_fd(unsigned long flags);

/**
* nonseq_files_fdmap - Must be called with @files->file_lock held. It forces
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-06-07 00:35    [W:0.027 / U:0.396 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site