linux/fs
Joel Becker 631d1febab configfs: config item dependancies.
Sometimes other drivers depend on particular configfs items.  For
example, ocfs2 mounts depend on a heartbeat region item.  If that
region item is removed with rmdir(2), the ocfs2 mount must BUG or go
readonly.  Not happy.

This provides two additional API calls: configfs_depend_item() and
configfs_undepend_item().  A client driver can call
configfs_depend_item() on an existing item to tell configfs that it is
depended on.  configfs will then return -EBUSY from rmdir(2) for that
item.  When the item is no longer depended on, the client driver calls
configfs_undepend_item() on it.

These API cannot be called underneath any configfs callbacks, as
they will conflict.  They can block and allocate.  A client driver
probably shouldn't calling them of its own gumption.  Rather it should
be providing an API that external subsystems call.

How does this work?  Imagine the ocfs2 mount process.  When it mounts,
it asks for a heart region item.  This is done via a call into the
heartbeat code.  Inside the heartbeat code, the region item is looked
up.  Here, the heartbeat code calls configfs_depend_item().  If it
succeeds, then heartbeat knows the region is safe to give to ocfs2.
If it fails, it was being torn down anyway, and heartbeat can gracefully
pass up an error.

[ Fixed some bad whitespace in configfs.txt. --Mark ]

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-07-10 17:18:59 -07:00
..
9p Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
adfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
affs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
afs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
autofs Replace pid_t in autofs with struct pid reference 2007-05-11 08:29:36 -07:00
autofs4 Fix some coding-style errors in autofs 2007-05-11 08:29:36 -07:00
befs Remove SLAB_CTOR_CONSTRUCTOR 2007-05-17 05:23:04 -07:00
bfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
cifs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
coda sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
configfs configfs: config item dependancies. 2007-07-10 17:18:59 -07:00
cramfs mm: make read_cache_page synchronous 2007-05-07 12:12:51 -07:00
debugfs remove "struct subsystem" as it is no longer needed 2007-05-02 18:57:59 -07:00
devpts devpts: add fsnotify create event 2007-05-08 11:14:59 -07:00
dlm configfs: Convert subsystem semaphore to mutex 2007-07-10 17:10:56 -07:00
ecryptfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
efs Remove SLAB_CTOR_CONSTRUCTOR 2007-05-17 05:23:04 -07:00
exportfs header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
ext2 xip sendfile removal 2007-07-10 08:04:15 +02:00
ext3 sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
ext4 sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
fat sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
freevxfs freevxfs: possible null pointer dereference fix 2007-05-08 11:14:59 -07:00
fuse sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
gfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw 2007-07-10 13:56:13 -07:00
hfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
hfsplus sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
hostfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
hpfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
hppfs [PATCH] Mark struct super_operations const 2007-02-12 09:48:47 -08:00
hugetlbfs shm: fix the filename of hugetlb sysv shared memory 2007-06-16 13:16:16 -07:00
isofs Remove SLAB_CTOR_CONSTRUCTOR 2007-05-17 05:23:04 -07:00
jbd fix file specification in comments 2007-05-09 08:58:16 +02:00
jbd2 fix file specification in comments 2007-05-09 08:58:16 +02:00
jffs2 sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
jfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
lockd NLM: Fix sparse warnings 2007-05-14 19:33:46 -04:00
minix sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
msdos [PATCH] mark struct inode_operations const 2 2007-02-12 09:48:46 -08:00
ncpfs Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
nfs sendfile: convert nfs to using splice_read() 2007-07-10 08:04:14 +02:00
nfs_common [PATCH] nfs_common endianness annotations 2006-10-20 10:26:41 -07:00
nfsd pipe: change the ->pin() operation to ->confirm() 2007-07-10 08:04:15 +02:00
nls [PATCH] fs: make nls_cp936.c handle some U00XY characters and U20AC correctly 2006-12-07 08:39:46 -08:00
ntfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
ocfs2 configfs: Convert subsystem semaphore to mutex 2007-07-10 17:10:56 -07:00
openpromfs Remove SLAB_CTOR_CONSTRUCTOR 2007-05-17 05:23:04 -07:00
partitions [S390] fixed cdl-format detection. 2007-07-10 11:24:44 +02:00
proc sched: scheduler debugging, core 2007-07-09 18:52:00 +02:00
qnx4 sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
ramfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
reiserfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
romfs Remove SLAB_CTOR_CONSTRUCTOR 2007-05-17 05:23:04 -07:00
smbfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
sysfs sysfs: fix race condition around sd->s_dentry, take#2 2007-06-12 16:08:47 -07:00
sysv sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
udf sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
ufs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
vfat [PATCH] mark struct inode_operations const 3 2007-02-12 09:48:46 -08:00
xfs sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
Kconfig Remove obsolete fat_cvf help text 2007-05-09 08:58:15 +02:00
Kconfig.binfmt fs: Kill sh dependency for binfmt_flat. 2007-05-21 14:34:00 +09:00
Makefile signal/timer/event: eventfd core 2007-05-11 08:29:36 -07:00
aio.c signal/timer/event: KAIO eventfd support example 2007-05-11 08:29:37 -07:00
anon_inodes.c signal/timer/event fds: anonymous inode source 2007-05-11 08:29:36 -07:00
attr.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
bad_inode.c sendfile: remove bad_sendfile() from bad_file_ops 2007-07-10 08:04:15 +02:00
binfmt_aout.c [PATCH] VFS: change struct file to use struct path 2006-12-08 08:28:41 -08:00
binfmt_elf.c Fix elf_core_dump() when writing arch specific notes (spu coredumps) 2007-07-06 10:23:43 -07:00
binfmt_elf_fdpic.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
binfmt_em86.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
binfmt_flat.c nommu: report correct errno in message 2007-06-08 17:23:32 -07:00
binfmt_misc.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
binfmt_script.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
binfmt_som.c [PARISC] Fix fs/binfmt_som.c 2006-10-04 06:51:26 -06:00
bio.c unexport bio_{,un}map_user 2007-07-10 08:03:34 +02:00
block_dev.c sendfile: remove .sendfile from filesystems that use generic_file_sendfile() 2007-07-10 08:04:13 +02:00
buffer.c Fix "fs: convert core functions to zero_user_page" 2007-05-21 09:15:32 -07:00
char_dev.c [PATCH] remove protection of LANANA-reserved majors 2007-04-04 21:12:47 -07:00
compat.c optimize compat_core_sys_select() by a using stack space for small fd sets 2007-05-23 20:14:12 -07:00
compat_ioctl.c fix compat console unimap regression 2007-05-25 17:37:46 -07:00
dcache.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
dcookies.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
direct-io.c dio: remove bogus refcounting BUG_ON 2007-07-03 18:23:23 -07:00
dnotify.c [PATCH] VFS: change struct file to use struct path 2006-12-08 08:28:41 -08:00
dquot.c circular locking dependency found in QUOTA OFF 2007-05-17 05:23:05 -07:00
drop_caches.c [PATCH] remove invalidate_inode_pages() 2007-02-11 10:51:31 -08:00
eventfd.c eventfd use waitqueue lock ... 2007-05-18 13:09:34 -07:00
eventpoll.c epoll: move kfree inside ep_free 2007-05-15 08:54:00 -07:00
exec.c uselib: add missing MNT_NOEXEC check 2007-05-23 20:14:13 -07:00
fcntl.c [PATCH] fdtable: Make fdarray and fdsets equal in size 2006-12-10 09:57:22 -08:00
fifo.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
file.c [PATCH] fdtable: Provide free_fdtable() wrapper 2006-12-22 08:55:50 -08:00
file_table.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
filesystems.c add filesystem subtype support 2007-05-08 11:15:01 -07:00
fs-writeback.c Write back inode data pages even when the inode itself is locked 2007-01-26 12:53:20 -08:00
generic_acl.c [PATCH] Generic infrastructure for acls 2006-09-29 09:18:24 -07:00
inode.c Remove SLAB_CTOR_CONSTRUCTOR 2007-05-17 05:23:04 -07:00
inotify.c Introduce a handy list_first_entry macro 2007-05-08 11:15:11 -07:00
inotify_user.c [PATCH] inotify: read return val fix 2007-02-12 09:48:28 -08:00
internal.h cleanup compat ioctl handling 2007-05-08 11:15:09 -07:00
ioctl.c vanishing ioctl handler debugging 2007-06-04 13:25:10 -07:00
ioprio.c [PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_task 2007-02-12 09:48:32 -08:00
libfs.c fs/libfs.c: >80 columns line break fix 2007-05-09 06:44:57 +02:00
locks.c Remove SLAB_CTOR_CONSTRUCTOR 2007-05-17 05:23:04 -07:00
mbcache.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
mpage.c consolidate generic_writepages and mpage_writepages 2007-05-11 08:29:35 -07:00
namei.c [PATCH] complete message queue auditing 2007-05-11 05:38:26 -04:00
namespace.c check privileges before setting mount propagation 2007-05-08 11:15:12 -07:00
nfsctl.c
no-block.c [PATCH] BLOCK: Make it possible to disable the block layer [try #6] 2006-09-30 20:52:31 +02:00
open.c Remove suid/sgid bits on [f]truncate() 2007-05-08 20:10:00 -07:00
pipe.c pipe: add documentation and comments 2007-07-10 08:04:16 +02:00
pnode.c Introduce a handy list_first_entry macro 2007-05-08 11:15:11 -07:00
pnode.h [PATCH] rename struct namespace to struct mnt_namespace 2006-12-08 08:28:51 -08:00
posix_acl.c [PATCH] kmemdup: some users 2006-10-01 00:39:19 -07:00
quota.c circular locking dependency found in QUOTA OFF 2007-05-17 05:23:05 -07:00
quota_v1.c
quota_v2.c
read_write.c Remove remnants of sendfile() 2007-07-10 08:04:15 +02:00
read_write.h [PATCH] Remove readv/writev methods and use aio_read/aio_write instead 2006-10-01 00:39:28 -07:00
readdir.c ROUND_UP macro cleanup in fs/(select|compat|readdir).c 2007-05-08 11:15:09 -07:00
select.c Style fix in fs/select.c 2007-05-09 07:10:02 +02:00
seq_file.c [PATCH] VFS: change struct file to use struct path 2006-12-08 08:28:41 -08:00
signalfd.c avoid spurious POLLIN returns in signalfd 2007-06-28 11:34:54 -07:00
splice.c pipe: add documentation and comments 2007-07-10 08:04:16 +02:00
stack.c [PATCH] fs/stack.c: Copy i_nlink after all other attributes are copied 2007-02-19 14:21:50 -08:00
stat.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
super.c add filesystem subtype support 2007-05-08 11:15:01 -07:00
sync.c Introduce fixed sys_sync_file_range2() syscall, implement on PowerPC and ARM 2007-06-28 11:38:30 -07:00
timerfd.c timerfd use waitqueue lock ... 2007-05-18 13:09:34 -07:00
utimes.c Fix permission checking for the new utimensat() system call 2007-07-08 12:02:55 -07:00
xattr.c [PATCH] audit inode for all xattr syscalls 2007-05-11 05:38:26 -04:00
xattr_acl.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00