fuse: add blksize field to fuse_attr
There are cases when the filesystem will be passed the buffer from a single
read or write call, namely:
1) in 'direct-io' mode (not O_DIRECT), read/write requests don't go
through the page cache, but go directly to the userspace fs
2) currently buffered writes are done with single page requests, but
if Nick's ->perform_write() patch goes it, it will be possible to
do larger write requests. But only if the original write() was
also bigger than a page.
In these cases the filesystem might want to give a hint to the app
about the optimal I/O size.
Allow the userspace filesystem to supply a blksize value to be returned by
stat() and friends. If the field is zero, it defaults to the old
PAGE_CACHE_SIZE value.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 7d4fa5b..d0c4370 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -15,6 +15,7 @@
* - new fuse_getattr_in input argument of GETATTR
* - add lk_flags in fuse_lk_in
* - add lock_owner field to fuse_setattr_in, fuse_read_in and fuse_write_in
+ * - add blksize field to fuse_attr
*/
#include <asm/types.h>
@@ -53,6 +54,8 @@
__u32 uid;
__u32 gid;
__u32 rdev;
+ __u32 blksize;
+ __u32 padding;
};
struct fuse_kstatfs {
@@ -177,6 +180,8 @@
/* The read buffer is required to be at least 8k, but may be much larger */
#define FUSE_MIN_READ_BUFFER 8192
+#define FUSE_COMPAT_ENTRY_OUT_SIZE 120
+
struct fuse_entry_out {
__u64 nodeid; /* Inode ID */
__u64 generation; /* Inode generation: nodeid:gen must
@@ -198,6 +203,8 @@
__u64 fh;
};
+#define FUSE_COMPAT_ATTR_OUT_SIZE 96
+
struct fuse_attr_out {
__u64 attr_valid; /* Cache timeout for the attributes */
__u32 attr_valid_nsec;