2019-08-18 18:21:39

by Trond Myklebust

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Subject: [PATCH v2 00/16] Cache open file descriptors in knfsd

When a NFSv3 READ or WRITE request comes in, the first thing knfsd has
to do is open a new file descriptor. 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.

-------
v2:
- Fix a double semicolon in fs/nfsd/filecache.c
- Adjust changelog for "nfsd: rip out the raparms cache" as per Chuck's
request.
-------

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 | 61 +++
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, 1464 insertions(+), 382 deletions(-)
create mode 100644 fs/nfsd/filecache.c
create mode 100644 fs/nfsd/filecache.h

--
2.21.0


2019-08-19 15:02:33

by J. Bruce Fields

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Subject: Re: [PATCH v2 00/16] Cache open file descriptors in knfsd

On Sun, Aug 18, 2019 at 02:18:43PM -0400, Trond Myklebust wrote:
> v2:
> - Fix a double semicolon in fs/nfsd/filecache.c
> - Adjust changelog for "nfsd: rip out the raparms cache" as per Chuck's
> request.

Thanks, replaced the series in my -next branch with this version.

--b.

2019-08-19 15:12:24

by J. Bruce Fields

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Subject: Re: [PATCH v2 00/16] Cache open file descriptors in knfsd

On Mon, Aug 19, 2019 at 11:01:58AM -0400, J. Bruce Fields wrote:
> On Sun, Aug 18, 2019 at 02:18:43PM -0400, Trond Myklebust wrote:
> > v2:
> > - Fix a double semicolon in fs/nfsd/filecache.c
> > - Adjust changelog for "nfsd: rip out the raparms cache" as per Chuck's
> > request.
>
> Thanks, replaced the series in my -next branch with this version.

Whoops, forgot about some fixes required for the /proc/fs/nfsd/clients
stuff. We'll see if the various robots notice that my -next tree
briefly didn't compile.

--b.