| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 4 Sep 2006 22:08:36 -0700
From: Vadim Lobanov <vlobanov@...akeasy.net>
To: akpm@...l.org, linux-kernel@...r.kernel.org
Subject: [PATCH] Clean up expand_fdtable() and expand_files().
Hi,
This patch performs a code cleanup against the expand_fdtable() and
expand_files() functions inside fs/file.c. It aims to make the flow of code
within these functions simpler and easier to understand, via added comments
and modest refactoring. The patch was generated against 2.6.18-rc5-mm1, and
was successfully run live. Please apply.
(I'm trying out KMail for this patch. I tested this mailer beforehand to make
sure the patch will come out unmangled, but, as with all things software,
success is far from guaranteed. :) Please yell if the patch is borked.)
Signed-off-by: Vadim Lobanov <vlobanov@...akeasy.net>
diff -Npru linux-a/fs/file.c linux-b/fs/file.c
--- linux-a/fs/file.c 2006-09-01 20:34:12.000000000 -0700
+++ linux-b/fs/file.c 2006-09-04 16:42:33.000000000 -0700
@@ -296,37 +296,30 @@ static int expand_fdtable(struct files_s
__releases(files->file_lock)
__acquires(files->file_lock)
{
- int error = 0;
- struct fdtable *fdt;
- struct fdtable *nfdt = NULL;
+ struct fdtable *new_fdt, *cur_fdt;
spin_unlock(&files->file_lock);
- nfdt = alloc_fdtable(nr);
- if (!nfdt) {
- error = -ENOMEM;
- spin_lock(&files->file_lock);
- goto out;
- }
-
+ new_fdt = alloc_fdtable(nr);
spin_lock(&files->file_lock);
- fdt = files_fdtable(files);
+ if (!new_fdt)
+ return -ENOMEM;
/*
- * Check again since another task may have expanded the
- * fd table while we dropped the lock
+ * Check again since another task may have expanded the fd table while
+ * we dropped the lock
*/
- if (nr >= fdt->max_fds || nr >= fdt->max_fdset) {
- copy_fdtable(nfdt, fdt);
+ cur_fdt = files_fdtable(files);
+ if (nr >= cur_fdt->max_fds || nr >= cur_fdt->max_fdset) {
+ /* Continue as planned */
+ copy_fdtable(new_fdt, cur_fdt);
+ rcu_assign_pointer(files->fdt, new_fdt);
+ free_fdtable(cur_fdt);
} else {
- /* Somebody expanded while we dropped file_lock */
+ /* Somebody else expanded, so undo our attempt */
spin_unlock(&files->file_lock);
- __free_fdtable(nfdt);
+ __free_fdtable(new_fdt);
spin_lock(&files->file_lock);
- goto out;
}
- rcu_assign_pointer(files->fdt, nfdt);
- free_fdtable(fdt);
-out:
- return error;
+ return 1;
}
/*
@@ -336,23 +329,19 @@ out:
*/
int expand_files(struct files_struct *files, int nr)
{
- int err, expand = 0;
struct fdtable *fdt;
fdt = files_fdtable(files);
- if (nr >= fdt->max_fdset || nr >= fdt->max_fds) {
- if (fdt->max_fdset >= NR_OPEN ||
- fdt->max_fds >= NR_OPEN || nr >= NR_OPEN) {
- err = -EMFILE;
- goto out;
- }
- expand = 1;
- if ((err = expand_fdtable(files, nr)))
- goto out;
- }
- err = expand;
-out:
- return err;
+ /* Do we need to expand? */
+ if (nr < fdt->max_fdset && nr < fdt->max_fds)
+ return 0;
+ /* Can we expand? */
+ if (fdt->max_fdset >= NR_OPEN || fdt->max_fds >= NR_OPEN ||
+ nr >= NR_OPEN)
+ return -EMFILE;
+
+ /* All good, so we try */
+ return expand_fdtable(files, nr);
}
static void __devinit fdtable_defer_list_init(int cpu)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists