Don't set FUSE_CAP_PARALLEL_DIROPS by default

Allowing parallel dir operations could result in a crash in a filesystem
implementation that is not prepared for this.

To be safe keep this flag off by default (this is not a regression, since
there was no public release where this flag wasn't ignored).

If the filesystem wants better performance, then it should set this flag
explicitly.

Fixes: c9905341ea34 ("Pass FUSE_PARALLEL_DIROPS to kernel (#861)")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/include/fuse_common.h b/include/fuse_common.h
index a804134c201e60ebbcb752478429386e3f232a92..fedbaa93911f490c2d26b2944589d0946e16f72d 100644 (file)
--- a/include/fuse_common.h
+++ b/include/fuse_common.h
@@ -336,8 +336,6 @@ struct fuse_loop_config_v1 {
  * is unset, the FUSE kernel module will ensure that lookup() and
  * readdir() requests are never issued concurrently for the same
  * directory.
- *
- * This feature is enabled by default when supported by the kernel.
  */
 #define FUSE_CAP_PARALLEL_DIROPS        (1 << 18)
 

diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 41e626b4c893b20a8bd180260998a680a74340d7..d8f5466815eeefe949d22a3160572a0ec006bc6e 100644 (file)
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -2053,7 +2053,6 @@ void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
        if ((cond) && (se->conn.capable & (cap))) \
                se->conn.want |= (cap)
        LL_SET_DEFAULT(1, FUSE_CAP_ASYNC_READ);
-       LL_SET_DEFAULT(1, FUSE_CAP_PARALLEL_DIROPS);
        LL_SET_DEFAULT(1, FUSE_CAP_AUTO_INVAL_DATA);
        LL_SET_DEFAULT(1, FUSE_CAP_HANDLE_KILLPRIV);
        LL_SET_DEFAULT(1, FUSE_CAP_ASYNC_DIO);