[PATCH] v9fs: signal handling fixes
Multiple races can happen when v9fs is interrupted by a signal and Tflush
message is sent to the server. After v9fs sends Tflush it doesn't wait
until it receives Rflush, and possibly the response of the original
message. This behavior may confuse v9fs what fids are allocated by the
file server.
This patch fixes the races and the fid allocation.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@hera.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 133db36..2cb87ba 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -270,7 +270,10 @@
err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
if (err < 0) {
PRINT_FCALL_ERROR("clone error", fcall);
- goto put_fid;
+ if (fcall && fcall->id == RWALK)
+ goto clunk_fid;
+ else
+ goto put_fid;
}
kfree(fcall);
@@ -322,6 +325,9 @@
&fcall);
if (err < 0) {
+ if (fcall && fcall->id == RWALK)
+ goto clunk_fid;
+
PRINT_FCALL_ERROR("walk error", fcall);
v9fs_put_idpool(nfid, &v9ses->fidpool);
goto error;
@@ -640,19 +646,26 @@
}
result = v9fs_t_walk(v9ses, dirfidnum, newfid,
- (char *)dentry->d_name.name, NULL);
+ (char *)dentry->d_name.name, &fcall);
+
if (result < 0) {
- v9fs_put_idpool(newfid, &v9ses->fidpool);
+ if (fcall && fcall->id == RWALK)
+ v9fs_t_clunk(v9ses, newfid);
+ else
+ v9fs_put_idpool(newfid, &v9ses->fidpool);
+
if (result == -ENOENT) {
d_add(dentry, NULL);
dprintk(DEBUG_VFS,
"Return negative dentry %p count %d\n",
dentry, atomic_read(&dentry->d_count));
+ kfree(fcall);
return NULL;
}
dprintk(DEBUG_ERROR, "walk error:%d\n", result);
goto FreeFcall;
}
+ kfree(fcall);
result = v9fs_t_stat(v9ses, newfid, &fcall);
if (result < 0) {