| 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, 9 Jul 2012 15:41:25 -0700 (PDT)
From: Hugh Dickins <hughd@...gle.com>
To: Andrew Morton <akpm@...ux-foundation.org>
cc: Christoph Hellwig <hch@...radead.org>,
Josef Bacik <josef@...hat.com>,
Andi Kleen <andi@...stfloor.org>,
Andreas Dilger <adilger@...ger.ca>,
Dave Chinner <david@...morbit.com>,
Marco Stornelli <marco.stornelli@...il.com>,
Jeff liu <jeff.liu@...cle.com>,
Chris Mason <chris.mason@...ionio.com>, linux-mm@...ck.org,
linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] tmpfs: revert SEEK_DATA and SEEK_HOLE
Revert 4fb5ef089b28 ("tmpfs: support SEEK_DATA and SEEK_HOLE").
I believe it's correct, and it's been nice to have from rc1 to rc6;
but as the original commit said:
I don't know who actually uses SEEK_DATA or SEEK_HOLE, and whether it
would be of any use to them on tmpfs. This code adds 92 lines and 752
bytes on x86_64 - is that bloat or worthwhile?
Nobody asked for it, so I conclude that it's bloat: let's revert tmpfs
to the dumb generic support for v3.5. We can always reinstate it later
if useful, and anyone needing it in a hurry can just get it out of git.
Signed-off-by: Hugh Dickins <hughd@...gle.com>
Cc: Christoph Hellwig <hch@...radead.org>
Cc: Josef Bacik <josef@...hat.com>
Cc: Andi Kleen <andi@...stfloor.org>
Cc: Andreas Dilger <adilger@...ger.ca>
Cc: Dave Chinner <david@...morbit.com>
Cc: Marco Stornelli <marco.stornelli@...il.com>
Cc: Jeff liu <jeff.liu@...cle.com>
Cc: Chris Mason <chris.mason@...ionio.com>
---
But if someone protests at this reversion, of course we can drop it.
mm/shmem.c | 94 ---------------------------------------------------
1 file changed, 1 insertion(+), 93 deletions(-)
--- 3.5-rc6/mm/shmem.c 2012-07-07 18:20:40.635328642 -0700
+++ linux/mm/shmem.c 2012-07-07 19:20:02.986950655 -0700
@@ -1692,98 +1692,6 @@ static ssize_t shmem_file_splice_read(st
return error;
}
-/*
- * llseek SEEK_DATA or SEEK_HOLE through the radix_tree.
- */
-static pgoff_t shmem_seek_hole_data(struct address_space *mapping,
- pgoff_t index, pgoff_t end, int origin)
-{
- struct page *page;
- struct pagevec pvec;
- pgoff_t indices[PAGEVEC_SIZE];
- bool done = false;
- int i;
-
- pagevec_init(&pvec, 0);
- pvec.nr = 1; /* start small: we may be there already */
- while (!done) {
- pvec.nr = shmem_find_get_pages_and_swap(mapping, index,
- pvec.nr, pvec.pages, indices);
- if (!pvec.nr) {
- if (origin == SEEK_DATA)
- index = end;
- break;
- }
- for (i = 0; i < pvec.nr; i++, index++) {
- if (index < indices[i]) {
- if (origin == SEEK_HOLE) {
- done = true;
- break;
- }
- index = indices[i];
- }
- page = pvec.pages[i];
- if (page && !radix_tree_exceptional_entry(page)) {
- if (!PageUptodate(page))
- page = NULL;
- }
- if (index >= end ||
- (page && origin == SEEK_DATA) ||
- (!page && origin == SEEK_HOLE)) {
- done = true;
- break;
- }
- }
- shmem_deswap_pagevec(&pvec);
- pagevec_release(&pvec);
- pvec.nr = PAGEVEC_SIZE;
- cond_resched();
- }
- return index;
-}
-
-static loff_t shmem_file_llseek(struct file *file, loff_t offset, int origin)
-{
- struct address_space *mapping;
- struct inode *inode;
- pgoff_t start, end;
- loff_t new_offset;
-
- if (origin != SEEK_DATA && origin != SEEK_HOLE)
- return generic_file_llseek_size(file, offset, origin,
- MAX_LFS_FILESIZE);
- mapping = file->f_mapping;
- inode = mapping->host;
- mutex_lock(&inode->i_mutex);
- /* We're holding i_mutex so we can access i_size directly */
-
- if (offset < 0)
- offset = -EINVAL;
- else if (offset >= inode->i_size)
- offset = -ENXIO;
- else {
- start = offset >> PAGE_CACHE_SHIFT;
- end = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- new_offset = shmem_seek_hole_data(mapping, start, end, origin);
- new_offset <<= PAGE_CACHE_SHIFT;
- if (new_offset > offset) {
- if (new_offset < inode->i_size)
- offset = new_offset;
- else if (origin == SEEK_DATA)
- offset = -ENXIO;
- else
- offset = inode->i_size;
- }
- }
-
- if (offset >= 0 && offset != file->f_pos) {
- file->f_pos = offset;
- file->f_version = 0;
- }
- mutex_unlock(&inode->i_mutex);
- return offset;
-}
-
static long shmem_fallocate(struct file *file, int mode, loff_t offset,
loff_t len)
{
@@ -2787,7 +2695,7 @@ static const struct address_space_operat
static const struct file_operations shmem_file_operations = {
.mmap = shmem_mmap,
#ifdef CONFIG_TMPFS
- .llseek = shmem_file_llseek,
+ .llseek = generic_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
.aio_read = shmem_file_aio_read,
--
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