linux-kernel - [PATCH 2/2] 9p: Fix the incorrect update of inode size in v9fs_file

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Date:	Wed, 26 Aug 2009 19:03:43 -0600
From:	Abhishek Kulkarni <adkulkar@...il.iu.edu>
To:	linux-kernel@...r.kernel.org
Cc:	v9fs-developer@...ts.sourceforge.net, ericvh@...il.com
Subject: [PATCH 2/2] 9p: Fix the incorrect update of inode size in v9fs_file_write()

When using the cache=loose flags, the inode's size was not being
updated correctly on a remote write. Thus subsequent reads of
the whole file resulted in a truncated read. Fix it.

Signed-off-by: Abhishek Kulkarni <adkulkar@...il.iu.edu>
---
 fs/9p/vfs_file.c |   15 ++++++++-------
 1 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index de7690e..cafaa46 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -32,6 +32,7 @@
 #include <linux/string.h>
 #include <linux/inet.h>
 #include <linux/list.h>
+#include <linux/pagemap.h>
 #include <asm/uaccess.h>
 #include <linux/idr.h>
 #include <net/9p/9p.h>
@@ -210,6 +211,7 @@ v9fs_file_write(struct file *filp, const char __user * data,
 	struct p9_client *clnt;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int origin = *offset;
+	unsigned long pg_start, pg_end;
 
 	P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
 		(int)count, (int)*offset);
@@ -225,7 +227,7 @@ v9fs_file_write(struct file *filp, const char __user * data,
 		if (count < rsize)
 			rsize = count;
 
-		n = p9_client_write(fid, NULL, data+total, *offset+total,
+		n = p9_client_write(fid, NULL, data+total, origin+total,
 									rsize);
 		if (n <= 0)
 			break;
@@ -234,13 +236,12 @@ v9fs_file_write(struct file *filp, const char __user * data,
 	} while (count > 0);
 
 	if (total > 0) {
-		invalidate_inode_pages2_range(inode->i_mapping, origin,
-								origin+total);
+		pg_start = origin >> PAGE_CACHE_SHIFT;
+		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
+		invalidate_inode_pages2_range(inode->i_mapping, pg_start,
+								pg_end);
 		*offset += total;
-	}
-
-	if (*offset > i_size_read(inode)) {
-		i_size_write(inode, *offset);
+		i_size_write(inode, i_size_read(inode) + total);
 		inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
 	}
 
-- 
1.6.3.3

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