linux.git/fs/9p/cache.h, branch v5.16

9p: Convert to using the netfs helper lib to do reads and caching

2021-11-03T08:45:02+00:00

Convert the 9p filesystem to use the netfs helper lib to handle readpage,
readahead and write_begin, converting those into a common issue_op for the
filesystem itself to handle. The netfs helper lib also handles reading
from fscache if a cache is available, and interleaving reads from both
sources.

This change also switches from the old fscache I/O API to the new one,
meaning that fscache no longer keeps track of netfs pages and instead does
async DIO between the backing files and the 9p file pagecache. As a part
of this change, the handling of PG_fscache changes. It now just means that
the cache has a write I/O operation in progress on a page (PG_locked
is used for a read I/O op).

Note that this is a cut-down version of the fscache rewrite and does not
change any of the cookie and cache coherency handling.

Changes
=======
ver #4:
- Rebase on top of folios.
- Don't use wait_on_page_bit_killable().

ver #3:
- v9fs_req_issue_op() needs to terminate the subrequest.
- v9fs_write_end() needs to call SetPageUptodate() a bit more often.
- It's not CONFIG_{AFS,V9FS}_FSCACHE[1]
- v9fs_init_rreq() should take a ref on the p9_fid and the cleanup should
drop it [from Dominique Martinet].

Signed-off-by: David Howells
Reviewed-and-tested-by: Dominique Martinet
cc: v9fs-developer@lists.sourceforge.net
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/YUm+xucHxED+1MJp@codewreck.org/ [1]
Link: https://lore.kernel.org/r/163162772646.438332.16323773205855053535.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/163189109885.2509237.7153668924503399173.stgit@warthog.procyon.org.uk/ # rfc v2
Link: https://lore.kernel.org/r/163363943896.1980952.1226527304649419689.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/163551662876.1877519.14706391695553204156.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/163584179557.4023316.11089762304657644342.stgit@warthog.procyon.org.uk # rebase on folio
Signed-off-by: Dominique Martinet

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188

2019-05-30T18:29:21+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to free software
  foundation 51 franklin street fifth floor boston ma 02111 1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 27 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Richard Fontana 
Reviewed-by: Alexios Zavras 
Reviewed-by: Steve Winslow 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.981318839@linutronix.de
Signed-off-by: Greg Kroah-Hartman

fs: 9p: cache.h: Add #define of include guard

2015-11-11T07:19:50+00:00

The include file was intended to have an include guard, but the #define
part is missing.

Signed-off-by: Tzvetelin Katchov 
Signed-off-by: Al Viro

9p: make v9fs_cache_inode_{get,put,set}_cookie empty inlines for !9P_CACHEFS

2013-10-25T03:34:47+00:00

Signed-off-by: Al Viro

fs/9p: When doing inode lookup compare qid details and inode mode bits.

2011-07-23T14:32:48+00:00

This make sure we don't use wrong inode from the inode hash. The inode number
of the file deleted is reused by the next file system object created
and if we only use inode number for inode hash lookup we could end up
with wrong struct inode.

Also compare inode generation number. Not all Linux file system provide
st_gen in userspace. So it could be 0;

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Eric Van Hensbergen

fs/9p: Add v9fs_inode

2011-03-15T14:57:39+00:00

Switch to the fscache code to v9fs_inode. We will later use
v9fs_inode in cache=loose mode to track the inode cache
validity timeout. Ie if we find an inode in cache older
that a specific jiffie range we will consider it stale

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Venkateswararao Jujjuri 
Signed-off-by: Eric Van Hensbergen

fs/9p: [fscache] wait for page write in cached mode

2011-03-15T14:57:37+00:00

We need to call fscache_wait_on_page_write in launder_page
for fscache

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Venkateswararao Jujjuri 
Signed-off-by: Eric Van Hensbergen

9p: Add fscache support to 9p

2009-09-23T18:03:46+00:00

This patch adds a persistent, read-only caching facility for
9p clients using the FS-Cache caching backend.

When the fscache facility is enabled, each inode is associated
with a corresponding vcookie which is an index into the FS-Cache
indexing tree. The FS-Cache indexing tree is indexed at 3 levels:
- session object associated with each mount.
- inode/vcookie
- actual data (pages)

A cache tag is chosen randomly for each session. These tags can
be read off /sys/fs/9p/caches and can be passed as a mount-time
parameter to re-attach to the specified caching session.

Signed-off-by: Abhishek Kulkarni 
Signed-off-by: Eric Van Hensbergen