ShengLi has uploaded this change for review. ( https://review.gerrithub.io/c/ffilz/nfs-ganesha/+/1254771?usp=email ) Change subject: FSAL_CEPH: keep directory streams open between READDIR calls ...................................................................... FSAL_CEPH: keep directory streams open between READDIR calls Each READDIR opened a new libcephfs directory stream. Reopening the stream discards its buffered entries and causes repeated MDS readdirs when the directory cannot be served from the libcephfs cache. Keep the stream and continue on it when a READDIR with the same credentials resumes within what it read, and the change attribute of the directory, fetched before reading, is unchanged. The Linux client keeps only part of a reply and resumes before where the stream is, and seeking back makes libcephfs drop its buffer. So the stream keeps a bounded window of recently read entries, with their name, cookie and inode number, and normally serves such a READDIR from the window and the libcephfs inode cache instead of seeking back. A stream is kept even at the end of the directory, unless one READDIR read all of it, as the client may still resume within the last reply. Kept streams are limited in number and released when idle, by the next READDIR or a reaper thread, as they hold inodes in libcephfs. They are also released when their export goes away, before the connection may be aborted or shut down, as their directory handles may still be around. In NFSv4.1 listing tests, 10k and 100k entry directories took 8 and 113 MDS readdirs instead of 138 and 1364. A directory that fits in the libcephfs cache was also left complete, so the next listing was served from it as long as it remained valid and was not trimmed. Change-Id: Iba3c5113a0d002a8f00435d860c6c82c75ba6334 Signed-off-by: Sheng Li <50203418+LiShengG@users.noreply.github.com> --- M src/FSAL/FSAL_CEPH/export.c M src/FSAL/FSAL_CEPH/handle.c M src/FSAL/FSAL_CEPH/internal.c M src/FSAL/FSAL_CEPH/internal.h M src/FSAL/FSAL_CEPH/main.c 5 files changed, 627 insertions(+), 45 deletions(-) git pull ssh://review.gerrithub.io:29418/ffilz/nfs-ganesha refs/changes/71/1254771/1 -- To view, visit https://review.gerrithub.io/c/ffilz/nfs-ganesha/+/1254771?usp=email To unsubscribe, or for help writing mail filters, visit https://review.gerrithub.io/settings?usp=email Gerrit-MessageType: newchange Gerrit-Project: ffilz/nfs-ganesha Gerrit-Branch: next Gerrit-Change-Id: Iba3c5113a0d002a8f00435d860c6c82c75ba6334 Gerrit-Change-Number: 1254771 Gerrit-PatchSet: 1 Gerrit-Owner: ShengLi <50203418+LiShengG@users.noreply.github.com>