linux/fs/9p
David Howells 402cb8dda9 fscache: Attach the index key and aux data to the cookie
Attach copies of the index key and auxiliary data to the fscache cookie so
that:

 (1) The callbacks to the netfs for this stuff can be eliminated.  This
     can simplify things in the cache as the information is still
     available, even after the cache has relinquished the cookie.

 (2) Simplifies the locking requirements of accessing the information as we
     don't have to worry about the netfs object going away on us.

 (3) The cache can do lazy updating of the coherency information on disk.
     As long as the cache is flushed before reboot/poweroff, there's no
     need to update the coherency info on disk every time it changes.

 (4) Cookies can be hashed or put in a tree as the index key is easily
     available.  This allows:

     (a) Checks for duplicate cookies can be made at the top fscache layer
     	 rather than down in the bowels of the cache backend.

     (b) Caching can be added to a netfs object that has a cookie if the
     	 cache is brought online after the netfs object is allocated.

A certain amount of space is made in the cookie for inline copies of the
data, but if it won't fit there, extra memory will be allocated for it.

The downside of this is that live cache operation requires more memory.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
2018-04-04 13:41:28 +01:00
..
acl.c 9p: fix a potential acl leak 2017-02-22 16:41:27 -08:00
acl.h 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 2013-02-26 02:46:07 -05:00
cache.c fscache: Attach the index key and aux data to the cookie 2018-04-04 13:41:28 +01:00
cache.h fs: 9p: cache.h: Add #define of include guard 2015-11-11 02:19:50 -05:00
fid.c 9p: constify ->d_name handling 2017-01-12 04:01:17 -05:00
fid.h 9p: use clone_fid() 2016-08-03 11:12:12 -04:00
Kconfig fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at 2018-01-01 12:45:37 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
v9fs_vfs.h 9p: switch p9_client_read() to passing struct iov_iter * 2015-04-11 22:28:27 -04:00
v9fs.c 9p: Implement show_options 2017-07-11 06:08:58 -04:00
v9fs.h 9p: Implement show_options 2017-07-11 06:08:58 -04:00
vfs_addr.c 9p: set page uptodate when required in write_end() 2017-10-11 09:30:08 -07:00
vfs_dentry.c VFS: normal filesystems (and lustre): d_inode() annotations 2015-04-15 15:06:57 -04:00
vfs_dir.c 9p: switch to ->iterate_shared() 2016-05-09 11:41:16 -04:00
vfs_file.c Writeback error handling fixes for v4.14 2017-09-06 14:11:03 -07:00
vfs_inode_dotl.c fs/9p: Compare qid.path in v9fs_test_inode 2017-10-23 23:10:01 -04:00
vfs_inode.c fs/9p: Compare qid.path in v9fs_test_inode 2017-10-23 23:10:01 -04:00
vfs_super.c Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
xattr.c 9p: use clone_fid() 2016-08-03 11:12:12 -04:00
xattr.h 9p: xattr simplifications 2015-11-13 20:34:33 -05:00