libfuse: fix fuse_get_context() in non fuse threads

fuse_interrupted(), fuse_get_context(), etc... crashed in non-fuse threads.

Instead return false, NULL or error depending on the function.

Reported by Michael Berlin

diff --git a/ChangeLog b/ChangeLog
index c4268b22149cae98b78650486030d5719122225e..247cd2910cf9fd4905a0172a9847008af169d4b1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-02-05  Miklos Szeredi <miklos@szeredi.hu>
+
+       * libfuse: fix fuse_get_context() in non fuse threads.  Reported
+       by Michael Berlin
+
 2013-02-04  Miklos Szeredi <miklos@szeredi.hu>
 
        * libfuse: fix crash in unlock_path().  Patch by Ratna Manoj

diff --git a/lib/fuse.c b/lib/fuse.c
index 7b6ce998e1229d742384a4c091b9421be89af410..6e3c43190136a0d813985eeb1d5221607779508e 100644 (file)
--- a/lib/fuse.c
+++ b/lib/fuse.c
@@ -2368,9 +2368,12 @@ static int lookup_path(struct fuse *f, fuse_ino_t nodeid,
 
 static struct fuse_context_i *fuse_get_context_internal(void)
 {
-       struct fuse_context_i *c;
+       return (struct fuse_context_i *) pthread_getspecific(fuse_context_key);
+}
 
-       c = (struct fuse_context_i *) pthread_getspecific(fuse_context_key);
+static struct fuse_context_i *fuse_create_context(struct fuse *f)
+{
+       struct fuse_context_i *c = fuse_get_context_internal();
        if (c == NULL) {
                c = (struct fuse_context_i *)
                        calloc(1, sizeof(struct fuse_context_i));
@@ -2383,7 +2386,11 @@ static struct fuse_context_i *fuse_get_context_internal(void)
                        abort();
                }
                pthread_setspecific(fuse_context_key, c);
+       } else {
+               memset(c, 0, sizeof(*c));
        }
+       c->ctx.fuse = f;
+
        return c;
 }
 
@@ -2423,10 +2430,9 @@ static void fuse_delete_context_key(void)
 
 static struct fuse *req_fuse_prepare(fuse_req_t req)
 {
-       struct fuse_context_i *c = fuse_get_context_internal();
+       struct fuse_context_i *c = fuse_create_context(req_fuse(req));
        const struct fuse_ctx *ctx = fuse_req_ctx(req);
        c->req = req;
-       c->ctx.fuse = req_fuse(req);
        c->ctx.uid = ctx->uid;
        c->ctx.gid = ctx->gid;
        c->ctx.pid = ctx->pid;
@@ -2470,10 +2476,8 @@ void fuse_fs_init(struct fuse_fs *fs, struct fuse_conn_info *conn)
 static void fuse_lib_init(void *data, struct fuse_conn_info *conn)
 {
        struct fuse *f = (struct fuse *) data;
-       struct fuse_context_i *c = fuse_get_context_internal();
 
-       memset(c, 0, sizeof(*c));
-       c->ctx.fuse = f;
+       fuse_create_context(f);
        conn->want |= FUSE_CAP_EXPORT_SUPPORT;
        fuse_fs_init(f->fs, conn);
 }
@@ -2491,10 +2495,8 @@ void fuse_fs_destroy(struct fuse_fs *fs)
 static void fuse_lib_destroy(void *data)
 {
        struct fuse *f = (struct fuse *) data;
-       struct fuse_context_i *c = fuse_get_context_internal();
 
-       memset(c, 0, sizeof(*c));
-       c->ctx.fuse = f;
+       fuse_create_context(f);
        fuse_fs_destroy(f->fs);
        f->fs = NULL;
 }
@@ -4189,18 +4191,31 @@ void fuse_exit(struct fuse *f)
 
 struct fuse_context *fuse_get_context(void)
 {
-       return &fuse_get_context_internal()->ctx;
+       struct fuse_context_i *c = fuse_get_context_internal();
+
+       if (c)
+               return &c->ctx;
+       else
+               return NULL;
 }
 
 int fuse_getgroups(int size, gid_t list[])
 {
-       fuse_req_t req = fuse_get_context_internal()->req;
-       return fuse_req_getgroups(req, size, list);
+       struct fuse_context_i *c = fuse_get_context_internal();
+       if (!c)
+               return -EINVAL;
+
+       return fuse_req_getgroups(c->req, size, list);
 }
 
 int fuse_interrupted(void)
 {
-       return fuse_req_interrupted(fuse_get_context_internal()->req);
+       struct fuse_context_i *c = fuse_get_context_internal();
+
+       if (c)
+               return fuse_req_interrupted(c->req);
+       else
+               return 0;
 }
 
 void fuse_set_getcontext_func(struct fuse_context *(*func)(void))
@@ -4589,10 +4604,7 @@ void fuse_destroy(struct fuse *f)
                fuse_restore_intr_signal(f->conf.intr_signal);
 
        if (f->fs) {
-               struct fuse_context_i *c = fuse_get_context_internal();
-
-               memset(c, 0, sizeof(*c));
-               c->ctx.fuse = f;
+               fuse_create_context(f);
 
                for (i = 0; i < f->id_table.size; i++) {
                        struct node *node;