From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 20 Mar 2014 17:25:05 +0000 (-0700)
Subject: 3.13-stable patches
X-Git-Tag: v3.4.84~24
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6b0780cc64a173fe273643cc0afa46485e32fde0;p=thirdparty%2Fkernel%2Fstable-queue.git

3.13-stable patches

added patches:
	mm-readahead.c-fix-do_readahead-for-no-readpage-s.patch
---

diff --git a/queue-3.13/mm-readahead.c-fix-do_readahead-for-no-readpage-s.patch b/queue-3.13/mm-readahead.c-fix-do_readahead-for-no-readpage-s.patch
new file mode 100644
index 00000000000..6837637828a
--- /dev/null
+++ b/queue-3.13/mm-readahead.c-fix-do_readahead-for-no-readpage-s.patch
@@ -0,0 +1,77 @@
+From 58d5640ebdb273cc817b0d0cda7bcf2efbbc2ff7 Mon Sep 17 00:00:00 2001
+From: Mark Rutland <mark.rutland@arm.com>
+Date: Wed, 29 Jan 2014 14:05:51 -0800
+Subject: mm/readahead.c: fix do_readahead() for no readpage(s)
+
+From: Mark Rutland <mark.rutland@arm.com>
+
+commit 58d5640ebdb273cc817b0d0cda7bcf2efbbc2ff7 upstream.
+
+Commit 63d0f0a3c7e1 ("mm/readahead.c:do_readhead(): don't check for
+->readpage") unintentionally made do_readahead return 0 for all valid
+files regardless of whether readahead was supported, rather than the
+expected -EINVAL.  This gets forwarded on to userspace, and results in
+sys_readahead appearing to succeed in cases that don't make sense (e.g.
+when called on pipes or sockets).  This issue is detected by the LTP
+readahead01 testcase.
+
+As the exact return value of force_page_cache_readahead is currently
+never used, we can simplify it to return only 0 or -EINVAL (when
+readpage or readpages is missing).  With that in place we can simply
+forward on the return value of force_page_cache_readahead in
+do_readahead.
+
+This patch performs said change, restoring the expected semantics.
+
+Signed-off-by: Mark Rutland <mark.rutland@arm.com>
+Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Josh Boyer <jwboyer@fedoraproject.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ mm/readahead.c |   15 +++++----------
+ 1 file changed, 5 insertions(+), 10 deletions(-)
+
+--- a/mm/readahead.c
++++ b/mm/readahead.c
+@@ -211,8 +211,6 @@ out:
+ int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
+ 		pgoff_t offset, unsigned long nr_to_read)
+ {
+-	int ret = 0;
+-
+ 	if (unlikely(!mapping->a_ops->readpage && !mapping->a_ops->readpages))
+ 		return -EINVAL;
+ 
+@@ -226,15 +224,13 @@ int force_page_cache_readahead(struct ad
+ 			this_chunk = nr_to_read;
+ 		err = __do_page_cache_readahead(mapping, filp,
+ 						offset, this_chunk, 0);
+-		if (err < 0) {
+-			ret = err;
+-			break;
+-		}
+-		ret += err;
++		if (err < 0)
++			return err;
++
+ 		offset += this_chunk;
+ 		nr_to_read -= this_chunk;
+ 	}
+-	return ret;
++	return 0;
+ }
+ 
+ /*
+@@ -576,8 +572,7 @@ do_readahead(struct address_space *mappi
+ 	if (!mapping || !mapping->a_ops)
+ 		return -EINVAL;
+ 
+-	force_page_cache_readahead(mapping, filp, index, nr);
+-	return 0;
++	return force_page_cache_readahead(mapping, filp, index, nr);
+ }
+ 
+ SYSCALL_DEFINE3(readahead, int, fd, loff_t, offset, size_t, count)
diff --git a/queue-3.13/series b/queue-3.13/series
index 2ff3cf4a3dd..ff3c15926d0 100644
--- a/queue-3.13/series
+++ b/queue-3.13/series
@@ -93,3 +93,4 @@ iscsi-iser-target-fix-isert_conn-state-hung-shutdown-issues.patch
 iser-target-ignore-completions-for-frwrs-in-isert_cq_tx_work.patch
 iser-target-fix-post_send_buf_count-for-rdma-read-write.patch
 iser-target-fix-command-leak-for-tx_desc-comp_llnode_batch.patch
+mm-readahead.c-fix-do_readahead-for-no-readpage-s.patch