linux-kernel - [PATCH] tmpfs: truncate at i

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Message-ID: <1432049251-3298-1-git-send-email-jbacik@fb.com>
Date:	Tue, 19 May 2015 11:27:31 -0400
From:	Josef Bacik <jbacik@...com>
To:	<hughd@...gle.com>, <linux-mm@...ck.org>,
	<linux-kernel@...r.kernel.org>
Subject: [PATCH] tmpfs: truncate at i_size

If we fallocate past i_size with KEEP_SIZE, extend the file to use some but not
all of this space, and then truncate(i_size) we won't trim the excess
preallocated space.  We decided at LSF that we want to truncate the fallocated
bit past i_size when we truncate to i_size, which is what this patch does.
Thanks,

Signed-off-by: Josef Bacik <jbacik@...com>
---
 mm/shmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index de98137..089afde 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -569,7 +569,7 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
 			i_size_write(inode, newsize);
 			inode->i_ctime = inode->i_mtime = CURRENT_TIME;
 		}
-		if (newsize < oldsize) {
+		if (newsize <= oldsize) {
 			loff_t holebegin = round_up(newsize, PAGE_SIZE);
 			unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
 			shmem_truncate_range(inode, newsize, (loff_t)-1);
-- 
1.8.3.1

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