From: Pavel Machek <pavel@suse.cz>
Date: Thu, 24 Jul 2008 04:27:36 +0000 (-0700)
Subject: SYNC_FILE_RANGE_WRITE may and will block. Document that.
X-Git-Tag: v2.6.27-rc1~802
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cce770815869e9209171d819dfde89bcc738ab62;p=linux-2.6

SYNC_FILE_RANGE_WRITE may and will block. Document that.

[akpm@linux-foundation.org: fix comment text]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/fs/sync.c b/fs/sync.c
index 228e17b5e9..2967562d41 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -139,7 +139,8 @@ asmlinkage long sys_fdatasync(unsigned int fd)
  * before performing the write.
  *
  * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
- * range which are not presently under writeback.
+ * range which are not presently under writeback. Note that this may block for
+ * significant periods due to exhaustion of disk request structures.
  *
  * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
  * after performing the write.