fuse: allow control of adaptive readdirplus use
For some filesystems (e.g. GlusterFS), the cost of performing a
normal readdir and readdirplus are identical. Since adaptively
using readdirplus has no benefit for those systems, give
users/filesystems the option to control adaptive readdirplus use.
v2 of this patch incorporates Miklos's suggestion to simplify the code,
as well as improving consistency of macro names and documentation.
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 2b112d9..8506522 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -21,6 +21,8 @@
if (!fc->do_readdirplus)
return false;
+ if (!fc->readdirplus_auto)
+ return true;
if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
return true;
if (filp->f_pos == 0)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index fc55dd3..6aeba86 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -514,9 +514,12 @@
/** Use enhanced/automatic page cache invalidation. */
unsigned auto_inval_data:1;
- /** Does the filesystem support readdir-plus? */
+ /** Does the filesystem support readdirplus? */
unsigned do_readdirplus:1;
+ /** Does the filesystem want adaptive readdirplus? */
+ unsigned readdirplus_auto:1;
+
/** The number of requests waiting for completion */
atomic_t num_waiting;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 9876a87..01353ed 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -866,6 +866,8 @@
fc->auto_inval_data = 1;
if (arg->flags & FUSE_DO_READDIRPLUS)
fc->do_readdirplus = 1;
+ if (arg->flags & FUSE_READDIRPLUS_AUTO)
+ fc->readdirplus_auto = 1;
} else {
ra_pages = fc->max_read / PAGE_CACHE_SIZE;
fc->no_lock = 1;
@@ -893,7 +895,7 @@
FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
- FUSE_DO_READDIRPLUS;
+ FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO;
req->in.h.opcode = FUSE_INIT;
req->in.numargs = 1;
req->in.args[0].size = sizeof(*arg);