From 24833a2db44e39ec7652779a0fa2e70983b9cb4e Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 10 Feb 2021 11:15:17 -0300 Subject: [PATCH 06/54] virtiofsd: optionally return inode pointer from lo_do_lookup() RH-Author: Stefan Hajnoczi Message-id: <20210210111518.228148-3-stefanha@redhat.com> Patchwork-id: 101033 O-Subject: [RHEL-AV-8.4.0 qemu-kvm PATCH 2/3] virtiofsd: optionally return inode pointer from lo_do_lookup() Bugzilla: 1920740 RH-Acked-by: Laszlo Ersek RH-Acked-by: Greg Kurz RH-Acked-by: Dr. David Alan Gilbert 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 Reviewed-by: Greg Kurz Message-Id: <20210204150208.367837-3-stefanha@redhat.com> Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit 22d2ece71e533310da31f2857ebc4a00d91968b3) Signed-off-by: Stefan Hajnoczi Signed-off-by: Eduardo Lima (Etrunko) --- tools/virtiofsd/passthrough_ll.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 218e20e9d7..2bd050b620 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -843,11 +843,13 @@ 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; @@ -857,6 +859,10 @@ 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 @@ -924,7 +930,14 @@ 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; - lo_inode_put(lo, &inode); + + /* 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, @@ -959,7 +972,7 @@ 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 { @@ -1067,7 +1080,7 @@ 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; } @@ -1544,7 +1557,7 @@ 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; } @@ -1742,7 +1755,7 @@ 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; -- 2.27.0