Add support for FUSE_CANONICAL_PATH
This allows inotify requests on FUSE to be alerted when any
other stacked filesystem would trigger an inotify for the
same file.
Bug: 23904372
Change-Id: I4289b38230c314432eaf2c0d20d4ccefc058f59e
diff --git a/sdcard/sdcard.c b/sdcard/sdcard.c
index 5c18f26..9480e4a 100644
--- a/sdcard/sdcard.c
+++ b/sdcard/sdcard.c
@@ -48,6 +48,9 @@
#include <private/android_filesystem_config.h>
+/* FUSE_CANONICAL_PATH is not currently upstreamed */
+#define FUSE_CANONICAL_PATH 2016
+
/* README
*
* What is this?
@@ -1471,6 +1474,35 @@
return NO_STATUS;
}
+static int handle_canonical_path(struct fuse* fuse, struct fuse_handler* handler,
+ const struct fuse_in_header *hdr)
+{
+ struct node* node;
+ char path[PATH_MAX];
+ int len;
+
+ pthread_mutex_lock(&fuse->global->lock);
+ node = lookup_node_and_path_by_id_locked(fuse, hdr->nodeid,
+ path, sizeof(path));
+ TRACE("[%d] CANONICAL_PATH @ %" PRIx64 " (%s)\n", handler->token, hdr->nodeid,
+ node ? node->name : "?");
+ pthread_mutex_unlock(&fuse->global->lock);
+
+ if (!node) {
+ return -ENOENT;
+ }
+ if (!check_caller_access_to_node(fuse, hdr, node, R_OK)) {
+ return -EACCES;
+ }
+ len = strlen(path);
+ if (len + 1 > PATH_MAX)
+ len = PATH_MAX - 1;
+ path[PATH_MAX - 1] = 0;
+ fuse_reply(fuse, hdr->unique, path, len + 1);
+ return NO_STATUS;
+}
+
+
static int handle_fuse_request(struct fuse *fuse, struct fuse_handler* handler,
const struct fuse_in_header *hdr, const void *data, size_t data_len)
{
@@ -1586,6 +1618,10 @@
return handle_init(fuse, handler, hdr, req);
}
+ case FUSE_CANONICAL_PATH: { /* nodeid -> bytez[] */
+ return handle_canonical_path(fuse, handler, hdr);
+ }
+
default: {
TRACE("[%d] NOTIMPL op=%d uniq=%"PRIx64" nid=%"PRIx64"\n",
handler->token, hdr->opcode, hdr->unique, hdr->nodeid);