Sorry for the delay responding.... On Sun, Jun 30, 2019 at 09:52:24AM -0400, Trond Myklebust wrote: > When a NFSv3 READ or WRITE request comes in, the first thing knfsd has > to do is open a new file descriptor. I assume it shouldn't make a significant difference for NFSv4? > While this is often a relatively > inexpensive thing to do for most local filesystems, it is usually less > so for FUSE, clustered or networked filesystems that are being exported > by knfsd. > > This set of patches attempts to reduce some of that cost by caching > open file descriptors so that they may be reused by other incoming > READ/WRITE requests for the same file. > One danger when doing this, is that knfsd may end up caching file > descriptors for files that have been unlinked. In order to deal with > this issue, we use fsnotify to monitor the files, and have hooks to > evict those descriptors from the file cache if the i_nlink value > goes to 0. That was one of the objections to previous attempts at a file cache so it's good to have a simple solution. This attempt seems pretty well thought-out. I'll tentatively target this for 5.4 pending some more review and testing. --b. > > Jeff Layton (12): > sunrpc: add a new cache_detail operation for when a cache is flushed > locks: create a new notifier chain for lease attempts > nfsd: add a new struct file caching facility to nfsd > nfsd: hook up nfsd_write to the new nfsd_file cache > nfsd: hook up nfsd_read to the nfsd_file cache > nfsd: hook nfsd_commit up to the nfsd_file cache > nfsd: convert nfs4_file->fi_fds array to use nfsd_files > nfsd: convert fi_deleg_file and ls_file fields to nfsd_file > nfsd: hook up nfs4_preprocess_stateid_op to the nfsd_file cache > nfsd: have nfsd_test_lock use the nfsd_file cache > nfsd: rip out the raparms cache > nfsd: close cached files prior to a REMOVE or RENAME that would > replace target > > Trond Myklebust (4): > notify: export symbols for use by the knfsd file cache > vfs: Export flush_delayed_fput for use by knfsd. > nfsd: Fix up some unused variable warnings > nfsd: Fix the documentation for svcxdr_tmpalloc() > > fs/file_table.c | 1 + > fs/locks.c | 62 +++ > fs/nfsd/Kconfig | 1 + > fs/nfsd/Makefile | 3 +- > fs/nfsd/blocklayout.c | 3 +- > fs/nfsd/export.c | 13 + > fs/nfsd/filecache.c | 885 +++++++++++++++++++++++++++++++ > fs/nfsd/filecache.h | 60 +++ > fs/nfsd/nfs4layouts.c | 12 +- > fs/nfsd/nfs4proc.c | 83 +-- > fs/nfsd/nfs4state.c | 183 ++++--- > fs/nfsd/nfs4xdr.c | 31 +- > fs/nfsd/nfssvc.c | 16 +- > fs/nfsd/state.h | 10 +- > fs/nfsd/trace.h | 140 +++++ > fs/nfsd/vfs.c | 295 ++++------- > fs/nfsd/vfs.h | 9 +- > fs/nfsd/xdr4.h | 19 +- > fs/notify/fsnotify.h | 2 - > fs/notify/group.c | 2 + > fs/notify/mark.c | 6 + > include/linux/fs.h | 5 + > include/linux/fsnotify_backend.h | 2 + > include/linux/sunrpc/cache.h | 1 + > net/sunrpc/cache.c | 3 + > 25 files changed, 1465 insertions(+), 382 deletions(-) > create mode 100644 fs/nfsd/filecache.c > create mode 100644 fs/nfsd/filecache.h > > -- > 2.21.0
