linux/fs
David Howells ccc4fc3d11 FS-Cache: Implement the cookie management part of the netfs API
Implement the cookie management part of the FS-Cache netfs client API.  The
documentation and API header file were added in a previous patch.

This patch implements the following three functions:

 (1) fscache_acquire_cookie().

     Acquire a cookie to represent an object to the netfs.  If the object in
     question is a non-index object, then that object and its parent indices
     will be created on disk at this point if they don't already exist.  Index
     creation is deferred because an index may reside in multiple caches.

 (2) fscache_relinquish_cookie().

     Retire or release a cookie previously acquired.  At this point, the
     object on disk may be destroyed.

 (3) fscache_update_cookie().

     Update the in-cache representation of a cookie.  This is used to update
     the auxiliary data for coherency management purposes.

With this patch it is possible to have a netfs instruct a cache backend to
look up, validate and create metadata on disk and to destroy it again.
The ability to actually store and retrieve data in the objects so created is
added in later patches.

Note that these functions will never return an error.  _All_ errors are
handled internally to FS-Cache.

The worst that can happen is that fscache_acquire_cookie() may return a NULL
pointer - which is considered a negative cookie pointer and can be passed back
to any function that takes a cookie without harm.  A negative cookie pointer
merely suppresses caching at that level.

The stub in linux/fscache.h will detect inline the negative cookie pointer and
abort the operation as fast as possible.  This means that the compiler doesn't
have to set up for a call in that case.

See the documentation in Documentation/filesystems/caching/netfs-api.txt for
more information.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:38 +01:00
..
9p vfs: simple_set_mnt() should return void 2009-03-27 14:44:03 -04:00
adfs fs/adfs: return f_fsid for statfs(2) 2009-04-02 19:05:08 -07:00
affs fs/affs: return f_fsid for statfs(2) 2009-04-02 19:05:08 -07:00
afs proc 2/2: remove struct proc_dir_entry::owner 2009-03-31 01:14:44 +04:00
autofs constify dentry_operations: autofs, autofs4 2009-03-27 14:44:00 -04:00
autofs4 autofs4: fix lookup deadlock 2009-04-01 08:59:23 -07:00
befs fs/befs: return f_fsid for statfs(2) 2009-04-02 19:05:08 -07:00
bfs
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
cifs New helper - current_umask() 2009-03-31 23:00:26 -04:00
coda constify dentry_operations: misc filesystems 2009-03-27 14:44:00 -04:00
configfs constify dentry_operations: configfs 2009-03-27 14:44:03 -04:00
cramfs fs/cramfs: return f_fsid for statfs(2) 2009-04-02 19:05:08 -07:00
debugfs
devpts Merge code for single and multiple-instance mounts 2009-03-27 14:44:04 -04:00
dlm dlm: fix length calculation in compat code 2009-03-11 12:23:59 -05:00
ecryptfs ecryptfs: use kzfree() 2009-04-01 08:59:23 -07:00
efs fs/efs: return f_fsid for statfs(2) 2009-04-02 19:05:09 -07:00
exportfs
ext2 New helper - current_umask() 2009-03-31 23:00:26 -04:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
fat Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
freevxfs
fscache FS-Cache: Implement the cookie management part of the netfs API 2009-04-03 16:42:38 +01:00
fuse mm: page_mkwrite change prototype to match fault 2009-04-01 08:59:14 -07:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
hfs fs/hfs: return f_fsid for statfs(2) 2009-04-02 19:05:09 -07:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
hostfs constify dentry_operations: misc filesystems 2009-03-27 14:44:00 -04:00
hpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
hppfs hppfs: hppfs_read_file() may return -ERROR 2009-04-02 19:04:53 -07:00
hugetlbfs mm: reintroduce and deprecate rlimit based access for SHM_HUGETLB 2009-04-01 08:59:12 -07:00
isofs fs/isofs: return f_fsid for statfs(2) 2009-04-02 19:05:09 -07:00
jbd jbd: fix oops in jbd_journal_init_inode() on corrupted fs 2009-04-02 19:04:52 -07:00
jbd2 jbd2: Update locking coments 2009-03-27 17:20:40 -04:00
jffs2 New helper - current_umask() 2009-03-31 23:00:26 -04:00
jfs New helper - current_umask() 2009-03-31 23:00:26 -04:00
lockd NSM: Fix unaligned accesses in nsm_init_private() 2009-04-01 13:24:14 -04:00
minix fs/minix: return f_fsid for statfs(2) 2009-04-02 19:05:09 -07:00
ncpfs constify dentry_operations: misc filesystems 2009-03-27 14:44:00 -04:00
nfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
nfs_common
nfsd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
nls
notify fs: avoid I_NEW inodes 2009-03-27 14:44:05 -04:00
ntfs ntfs: remove private wrapper of endian helpers 2009-04-01 08:59:18 -07:00
ocfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
openpromfs
partitions Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6 2009-03-26 16:04:22 -07:00
proc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
qnx4 fs/qnx4: return f_fsid for statfs(2) 2009-04-02 19:05:10 -07:00
quota vfs: skip I_CLEAR state inodes 2009-04-02 19:04:48 -07:00
ramfs ramfs: add support for "mode=" mount option 2009-04-01 08:59:22 -07:00
reiserfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
romfs
smbfs constify dentry_operations: misc filesystems 2009-03-27 14:44:00 -04:00
squashfs fs/squashfs: return f_fsid for statfs(2) 2009-04-02 19:05:10 -07:00
sysfs mm: page_mkwrite change prototype to match fault: fix sysfs 2009-04-01 08:59:14 -07:00
sysv fs/sysv: return f_fsid for statfs(2) 2009-04-02 19:05:10 -07:00
ubifs mm: page_mkwrite change prototype to match fault 2009-04-01 08:59:14 -07:00
udf udf: Use lowercase names of quota functions 2009-03-26 02:18:36 +01:00
ufs fs/ufs: return f_fsid for statfs(2) 2009-04-02 19:05:10 -07:00
xfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
Kconfig FS-Cache: Add main configuration option, module entry points and debugging 2009-04-03 16:42:36 +01:00
Kconfig.binfmt
Makefile FS-Cache: Add main configuration option, module entry points and debugging 2009-04-03 16:42:36 +01:00
aio.c aio: lookup_ioctx can return the wrong value when looking up a bogus context 2009-03-19 15:57:18 -07:00
anon_inodes.c constify dentry_operations: rest 2009-03-27 14:44:03 -04:00
attr.c vfs: Use lowercase names of quota functions 2009-03-26 02:18:35 +01:00
bad_inode.c
binfmt_aout.c
binfmt_elf.c Trim includes in binfmt_elf 2009-03-31 23:00:27 -04:00
binfmt_elf_fdpic.c bin_elf_fdpic: check the return value of clear_user 2009-04-02 19:05:01 -07:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c Don't crap into descriptor table in binfmt_som 2009-03-31 23:00:28 -04:00
bio-integrity.c block: add private bio_set for bio integrity allocations 2009-03-24 12:35:17 +01:00
bio.c block: add private bio_set for bio integrity allocations 2009-03-24 12:35:17 +01:00
block_dev.c Cleanup after commit 585d3bc06f 2009-04-01 07:07:16 -04:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
char_dev.c
compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2009-03-01 21:35:16 -08:00
dcache.c Trim includes of fdtable.h 2009-03-31 23:00:28 -04:00
dcookies.c
direct-io.c
drop_caches.c vfs: skip I_CLEAR state inodes 2009-04-02 19:04:48 -07:00
eventfd.c epoll keyed wakeups: make eventfd use keyed wakeups 2009-04-01 08:59:20 -07:00
eventpoll.c epoll keyed wakeups: teach epoll about hints coming with the wakeup key 2009-04-01 08:59:20 -07:00
exec.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
fcntl.c Fix a lockdep warning in fasync_helper() 2009-03-30 08:00:24 -06:00
fifo.c
file.c
file_table.c Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6 2009-03-26 16:14:02 -07:00
filesystems.c
fs-writeback.c writeback: guard against jiffies wraparound on inode->dirtied_when checks (try #3) 2009-04-02 19:04:48 -07:00
fs_struct.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
generic_acl.c New helper - current_umask() 2009-03-31 23:00:26 -04:00
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-03-27 16:23:12 -07:00
internal.h New locking/refcounting for fs_struct 2009-03-31 23:00:26 -04:00
ioctl.c Rationalize fasync return values 2009-03-16 08:34:35 -06:00
ioprio.c
libfs.c vfs: simple_set_mnt() should return void 2009-03-27 14:44:03 -04:00
locks.c
mbcache.c
mpage.c Remove two unneeded exports and make two symbols static in fs/mpage.c 2009-04-01 07:38:54 -04:00
namei.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
namespace.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
nfsctl.c
no-block.c
open.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
pipe.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-03-27 16:23:12 -07:00
pnode.c
pnode.h
posix_acl.c
read_write.c preadv/pwritev: Add preadv and pwritev system calls. 2009-04-02 19:05:08 -07:00
read_write.h
readdir.c
select.c
seq_file.c cpumask: fix seq_bitmap_*() functions. 2009-03-30 22:05:11 +10:30
signalfd.c
splice.c FS-Cache: Recruit a page flags for cache management 2009-04-03 16:42:36 +01:00
stack.c
stat.c
super.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-03-27 16:23:12 -07:00
sync.c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6 2009-03-27 14:48:34 -07:00
timerfd.c
utimes.c
xattr.c
xattr_acl.c