debian/patches/extra/0005-virtiofsd-optionally-return-inode-pointer-from-lo_do.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Stefan Hajnoczi <stefanha@redhat.com>
   3 Date: Thu, 4 Feb 2021 18:34:36 +0000
   4 Subject: [PATCH] virtiofsd: optionally return inode pointer from
   5  lo_do_lookup()
   6
   7 lo_do_lookup() finds an existing inode or allocates a new one. It
   8 increments nlookup so that the inode stays alive until the client
   9 releases it.
  10
  11 Existing callers don't need the struct lo_inode so the function doesn't
  12 return it. Extend the function to optionally return the inode. The next
  13 commit will need it.
  14
  15 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
  16 Reviewed-by: Greg Kurz <groug@kaod.org>
  17 Message-Id: <20210204150208.367837-3-stefanha@redhat.com>
  18 Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  19 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  20 ---
  21  tools/virtiofsd/passthrough_ll.c | 29 +++++++++++++++++++++--------
  22  1 file changed, 21 insertions(+), 8 deletions(-)
  23
  24 diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
  25 index 218e20e9d7..2bd050b620 100644
  26 --- a/tools/virtiofsd/passthrough_ll.c
  27 +++ b/tools/virtiofsd/passthrough_ll.c
  28 @@ -843,11 +843,13 @@ static int do_statx(struct lo_data *lo, int dirfd, const char *pathname,
  29  }
  30
  31  /*
  32 - * Increments nlookup and caller must release refcount using
  33 - * lo_inode_put(&parent).
  34 + * Increments nlookup on the inode on success. unref_inode_lolocked() must be
  35 + * called eventually to decrement nlookup again. If inodep is non-NULL, the
  36 + * inode pointer is stored and the caller must call lo_inode_put().
  37   */
  38  static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
  39 -                        struct fuse_entry_param *e)
  40 +                        struct fuse_entry_param *e,
  41 +                        struct lo_inode **inodep)
  42  {
  43      int newfd;
  44      int res;
  45 @@ -857,6 +859,10 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
  46      struct lo_inode *inode = NULL;
  47      struct lo_inode *dir = lo_inode(req, parent);
  48
  49 +    if (inodep) {
  50 +        *inodep = NULL;
  51 +    }
  52 +
  53      /*
  54       * name_to_handle_at() and open_by_handle_at() can reach here with fuse
  55       * mount point in guest, but we don't have its inode info in the
  56 @@ -924,7 +930,14 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
  57          pthread_mutex_unlock(&lo->mutex);
  58      }
  59      e->ino = inode->fuse_ino;
  60 -    lo_inode_put(lo, &inode);
  61 +
  62 +    /* Transfer ownership of inode pointer to caller or drop it */
  63 +    if (inodep) {
  64 +        *inodep = inode;
  65 +    } else {
  66 +        lo_inode_put(lo, &inode);
  67 +    }
  68 +
  69      lo_inode_put(lo, &dir);
  70
  71      fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n", (unsigned long long)parent,
  72 @@ -959,7 +972,7 @@ static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name)
  73          return;
  74      }
  75
  76 -    err = lo_do_lookup(req, parent, name, &e);
  77 +    err = lo_do_lookup(req, parent, name, &e, NULL);
  78      if (err) {
  79          fuse_reply_err(req, err);
  80      } else {
  81 @@ -1067,7 +1080,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent,
  82          goto out;
  83      }
  84
  85 -    saverr = lo_do_lookup(req, parent, name, &e);
  86 +    saverr = lo_do_lookup(req, parent, name, &e, NULL);
  87      if (saverr) {
  88          goto out;
  89      }
  90 @@ -1544,7 +1557,7 @@ static void lo_do_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
  91
  92          if (plus) {
  93              if (!is_dot_or_dotdot(name)) {
  94 -                err = lo_do_lookup(req, ino, name, &e);
  95 +                err = lo_do_lookup(req, ino, name, &e, NULL);
  96                  if (err) {
  97                      goto error;
  98                  }
  99 @@ -1742,7 +1755,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
 100          }
 101
 102          fi->fh = fh;
 103 -        err = lo_do_lookup(req, parent, name, &e);
 104 +        err = lo_do_lookup(req, parent, name, &e, NULL);
 105      }
 106      if (lo->cache == CACHE_NONE) {
 107          fi->direct_io = 1;