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authorAbhishek Kulkarni <adkulkar@umail.iu.edu>2009-09-23 22:00:27 +0400
committerEric Van Hensbergen <ericvh@strongmad.austin.ibm.com>2009-09-23 22:03:46 +0400
commit60e78d2c993e58d890596d951fff77d5965adcd6 (patch)
tree3d53ed7254c613ef8d8de36fdceda25bc493f4f7 /fs/9p/vfs_file.c
parent637d020a02cd734bf27acfc56c6d942cddd9eb80 (diff)
downloadlinux-60e78d2c993e58d890596d951fff77d5965adcd6.tar.xz
9p: Add fscache support to 9p
This patch adds a persistent, read-only caching facility for 9p clients using the FS-Cache caching backend. When the fscache facility is enabled, each inode is associated with a corresponding vcookie which is an index into the FS-Cache indexing tree. The FS-Cache indexing tree is indexed at 3 levels: - session object associated with each mount. - inode/vcookie - actual data (pages) A cache tag is chosen randomly for each session. These tags can be read off /sys/fs/9p/caches and can be passed as a mount-time parameter to re-attach to the specified caching session. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'fs/9p/vfs_file.c')
-rw-r--r--fs/9p/vfs_file.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index cafaa46434ba..3902bf43a088 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -41,6 +41,7 @@
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
+#include "cache.h"
static const struct file_operations v9fs_cached_file_operations;
@@ -86,6 +87,10 @@ int v9fs_file_open(struct inode *inode, struct file *file)
/* enable cached file options */
if(file->f_op == &v9fs_file_operations)
file->f_op = &v9fs_cached_file_operations;
+
+#ifdef CONFIG_9P_FSCACHE
+ v9fs_cache_inode_set_cookie(inode, file);
+#endif
}
return 0;
@@ -238,8 +243,9 @@ v9fs_file_write(struct file *filp, const char __user * data,
if (total > 0) {
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);
+ if (inode->i_mapping && inode->i_mapping->nrpages)
+ invalidate_inode_pages2_range(inode->i_mapping,
+ pg_start, pg_end);
*offset += total;
i_size_write(inode, i_size_read(inode) + total);
inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;