virtiofsd: optionally return inode pointer from lo_do_lookup()

lo_do_lookup() finds an existing inode or allocates a new one. It
increments nlookup so that the inode stays alive until the client
releases it.

Existing callers don't need the struct lo_inode so the function doesn't
return it. Extend the function to optionally return the inode. The next
commit will need it.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210204150208.367837-3-stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2021-02-04 15:02:07 +00:00 committed by Dr. David Alan Gilbert
parent 8afaaee976
commit 22d2ece71e

View File

@ -831,11 +831,13 @@ static int do_statx(struct lo_data *lo, int dirfd, const char *pathname,
}
/*
* Increments nlookup and caller must release refcount using
* lo_inode_put(&parent).
* Increments nlookup on the inode on success. unref_inode_lolocked() must be
* called eventually to decrement nlookup again. If inodep is non-NULL, the
* inode pointer is stored and the caller must call lo_inode_put().
*/
static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
struct fuse_entry_param *e)
struct fuse_entry_param *e,
struct lo_inode **inodep)
{
int newfd;
int res;
@ -845,6 +847,10 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
struct lo_inode *inode = NULL;
struct lo_inode *dir = lo_inode(req, parent);
if (inodep) {
*inodep = NULL;
}
/*
* name_to_handle_at() and open_by_handle_at() can reach here with fuse
* mount point in guest, but we don't have its inode info in the
@ -913,7 +919,14 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
pthread_mutex_unlock(&lo->mutex);
}
e->ino = inode->fuse_ino;
/* Transfer ownership of inode pointer to caller or drop it */
if (inodep) {
*inodep = inode;
} else {
lo_inode_put(lo, &inode);
}
lo_inode_put(lo, &dir);
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n", (unsigned long long)parent,
@ -948,7 +961,7 @@ static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name)
return;
}
err = lo_do_lookup(req, parent, name, &e);
err = lo_do_lookup(req, parent, name, &e, NULL);
if (err) {
fuse_reply_err(req, err);
} else {
@ -1056,7 +1069,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent,
goto out;
}
saverr = lo_do_lookup(req, parent, name, &e);
saverr = lo_do_lookup(req, parent, name, &e, NULL);
if (saverr) {
goto out;
}
@ -1534,7 +1547,7 @@ static void lo_do_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
if (plus) {
if (!is_dot_or_dotdot(name)) {
err = lo_do_lookup(req, ino, name, &e);
err = lo_do_lookup(req, ino, name, &e, NULL);
if (err) {
goto error;
}
@ -1732,7 +1745,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
}
fi->fh = fh;
err = lo_do_lookup(req, parent, name, &e);
err = lo_do_lookup(req, parent, name, &e, NULL);
}
if (lo->cache == CACHE_NONE) {
fi->direct_io = 1;