fuse: fix LOOKUP vs INIT compat handling
Analysis from Marc:
"Commit 7078187a795f ("fuse: introduce fuse_simple_request() helper")
from the above pull request triggers some EIO errors for me in some tests
that rely on fuse
Looking at the code changes and a bit of debugging info I think there's a
general problem here that fuse_get_req checks and possibly waits for
fc->initialized, and this was always called first. But this commit
changes the ordering and in many places fc->minor is now possibly used
before fuse_get_req, and we can't be sure that fc has been initialized.
In my case fuse_lookup_init sets req->out.args[0].size to the wrong size
because fc->minor at that point is still 0, leading to the EIO error."
Fix by moving the compat adjustments into fuse_simple_request() to after
fuse_get_req().
This is also more readable than the original, since now compatibility is
handled in a single function instead of cluttering each operation.
Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Fixes: 7078187a795f ("fuse: introduce fuse_simple_request() helper")
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6749109..6a20f2f 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -424,8 +424,7 @@
args.in.h.opcode = FUSE_STATFS;
args.in.h.nodeid = get_node_id(dentry->d_inode);
args.out.numargs = 1;
- args.out.args[0].size =
- fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
+ args.out.args[0].size = sizeof(outarg);
args.out.args[0].value = &outarg;
err = fuse_simple_request(fc, &args);
if (!err)