NeilBrown 2b75869bba sysfs/kernfs: allow attributes to request write buffer be pre-allocated. ... md/raid allows metadata management to be performed in user-space. A various times, particularly on device failure, the metadata needs to be updated before further writes can be permitted. This means that the user-space program which updates metadata much not block on writeout, and so must not allocate memory. mlockall(MCL_CURRENT|MCL_FUTURE) and pre-allocation can avoid all memory allocation issues for user-memory, but that does not help kernel memory. Several kernel objects can be pre-allocated. e.g. files opened before any writes to the array are permitted. However some kernel allocation happens in places that cannot be pre-allocated. In particular, writes to sysfs files (to tell md that it can now allow writes to the array) allocate a buffer using GFP_KERNEL. This patch allows attributes to be marked as "PREALLOC". In that case the maximal buffer is allocated when the file is opened, and then used on each write instead of allocating a new buffer. As the same buffer is now shared for all writes on the same file description, the mutex is extended to cover full use of the buffer including the copy_from_user(). The new __ATTR_PREALLOC() 'or's a new flag in to the 'mode', which is inspected by sysfs_add_file_mode_ns() to determine if the file should be marked as requiring prealloc. Despite the comment, we *do* use ->seq_show together with ->prealloc in this patch. The next patch fixes that. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-11-07 10:53:25 -08:00
..
9p	9p: switch to %p[dD]	2014-10-09 02:39:04 -04:00
adfs	adfs: add __printf verification, fix format/argument mismatches	2014-08-08 15:57:24 -07:00
affs	fs/affs: remove redundant sys_tz declarations	2014-10-14 02:18:22 +02:00
afs	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-13 16:23:15 +02:00
autofs4	autofs4: d_manage() should return -EISDIR when appropriate in rcu-walk mode.	2014-10-14 02:18:16 +02:00
befs	fs/befs/btree.c: remove typedef befs_btree_node	2014-10-14 02:18:20 +02:00
bfs	fs/bfs: use bfs prefix for dump_imap	2014-08-08 15:57:24 -07:00
btrfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2014-11-01 10:41:26 -07:00
cachefiles	FS-Cache fixes	2014-10-14 08:40:15 +02:00
ceph	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client	2014-10-15 06:46:01 +02:00
cifs	[CIFS] Remove obsolete comment	2014-10-17 17:17:12 -05:00
coda	fs/coda: use linux/uaccess.h	2014-08-08 15:57:20 -07:00
configfs
cramfs	fs/cramfs/inode.c: use linux/uaccess.h	2014-08-08 15:57:25 -07:00
debugfs
devpts
dlm	dlm: fix missing endian conversion of rcom_status flags	2014-10-14 15:11:48 -05:00
ecryptfs	fs: limit filesystem stacking depth	2014-10-24 00:14:39 +02:00
efivarfs
efs	fs/efs/namei.c: return is not a function	2014-08-08 15:57:18 -07:00
exofs	Boaz Harrosh - Fix broken email address	2014-10-19 20:22:32 +03:00
exportfs
ext2	percpu_counter: add @gfp to percpu_counter_init()	2014-09-08 09:51:29 +09:00
ext3	ext3: Don't check quota format when there are no quota files	2014-10-22 09:02:48 +02:00
ext4	ext4: make ext4_ext_convert_to_initialized() return proper number of blocks	2014-10-30 10:53:17 -04:00
f2fs	f2fs: support volatile operations for transient data	2014-10-07 11:54:41 -07:00
fat	fat: remove redundant sys_tz declaration	2014-10-14 02:18:20 +02:00
freevxfs
fscache	fs/fscache/object-list.c: use __seq_open_private()	2014-10-13 17:52:21 +01:00
fuse	vfs: Make d_invalidate return void	2014-10-09 02:38:57 -04:00
gfs2	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-10-13 11:28:42 +02:00
hfs	fs/hfs/hfs_fs.h: remove redundant sys_tz declaration	2014-10-14 02:18:20 +02:00
hfsplus
hostfs	hostfs: support rename flags	2014-08-07 14:40:09 -04:00
hpfs	fs/hpfs/dnode.c: fix suspect code indent	2014-08-08 15:57:22 -07:00
hppfs
hugetlbfs
isofs	isofs: don't bother with ->d_op for normal case	2014-10-31 06:33:17 -04:00
jbd	fs, jbd: use a more generic hash function	2014-10-22 10:02:04 +02:00
jbd2	jbd2: use a better hash function for the revoke table	2014-10-30 10:53:17 -04:00
jffs2	[jffs2] kill wbuf_queued/wbuf_dwork_lock	2014-10-09 02:39:01 -04:00
jfs	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-13 16:23:15 +02:00
kernfs	sysfs/kernfs: allow attributes to request write buffer be pre-allocated.	2014-11-07 10:53:25 -08:00
lockd	File locking related changes for v3.18 (pile #1)	2014-10-11 13:21:34 -04:00
logfs	fs/logfs/readwrite.c: kernel-doc warning fixes	2014-08-06 18:01:12 -07:00
minix	minix zmap block counts calculation fix	2014-08-08 15:57:20 -07:00
ncpfs	fs/ncpfs/dir.c: remove redundant sys_tz declaration	2014-10-14 02:18:16 +02:00
nfs	Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd	2014-10-21 12:53:45 -07:00
nfs_common	lockd: move lockd's grace period handling into its own module	2014-09-17 16:33:11 -04:00
nfsd	nfsd4: fix crash on unknown operation number	2014-10-23 13:39:51 -04:00
nilfs2	nilfs2: improve the performance of fdatasync()	2014-10-14 02:18:20 +02:00
nls
notify	fsnotify: next_i is freed during fsnotify_unmount_inodes.	2014-10-29 16:33:14 -07:00
ntfs	NTFS: Bump version to 2.1.31.	2014-10-16 12:53:35 +01:00
ocfs2	ocfs2: fix d_splice_alias() return code checking	2014-10-29 16:33:15 -07:00
omfs	FS/OMFS: block number sanity check during fill_super operation	2014-10-14 02:18:22 +02:00
openpromfs
overlayfs	ovl: initialize ->is_cursor	2014-10-31 17:47:51 -04:00
proc	mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared	2014-10-14 02:18:28 +02:00
pstore	pstore: drop owner assignment from platform_drivers	2014-10-20 16:21:57 +02:00
qnx4
qnx6	fs/qnx6: update debugging to current functions	2014-08-08 15:57:26 -07:00
quota	quota: Properly return errors from dquot_writeback_dquots()	2014-10-22 09:08:03 +02:00
ramfs	fs/ramfs/file-nommu.c: replace count*size kzalloc by kcalloc	2014-08-08 15:57:18 -07:00
reiserfs	fs/reiserfs/journal.c: fix sparse context imbalance warning	2014-10-14 02:18:20 +02:00
romfs	fs/romfs/super.c: add blank line after declarations	2014-08-08 15:57:25 -07:00
squashfs	fs/squashfs/super.c: logging cleanup	2014-08-06 18:01:13 -07:00
sysfs	sysfs/kernfs: allow attributes to request write buffer be pre-allocated.	2014-11-07 10:53:25 -08:00
sysv
ubifs	UBIFS: Fix trivial typo in power_cut_emulated()	2014-09-30 09:29:44 +03:00
udf	udf: Fix loading of special inodes	2014-10-09 13:06:14 +02:00
ufs	fs/ufs/balloc.c: remove unused variable	2014-10-14 02:18:20 +02:00
xfs	Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block	2014-10-18 11:53:51 -07:00
aio.c	percpu_ref: add PERCPU_REF_INIT_* flags	2014-09-24 13:31:50 -04:00
anon_inodes.c
attr.c
bad_inode.c	bad_inode: add ->rename2()	2014-08-07 14:40:09 -04:00
binfmt_aout.c	handle suicide on late failure exits in execve() in search_binary_handler()	2014-10-09 02:39:00 -04:00
binfmt_elf_fdpic.c	handle suicide on late failure exits in execve() in search_binary_handler()	2014-10-09 02:39:00 -04:00
binfmt_elf.c	handle suicide on late failure exits in execve() in search_binary_handler()	2014-10-09 02:39:00 -04:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c	binfmt_misc: work around gcc-4.9 warning	2014-10-14 02:18:16 +02:00
binfmt_script.c
binfmt_som.c
block_dev.c	Return short read or 0 at end of a raw device, not EIO	2014-10-31 06:33:26 -04:00
buffer.c	fs: clarify rate limit suppressed buffer I/O errors	2014-10-21 13:55:11 -06:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c	vfs: move getname() from callers to do_mount()	2014-10-09 02:39:16 -04:00
coredump.c	coredump: add %i/%I in core_pattern to report the tid of the crashed thread	2014-10-14 02:18:21 +02:00
dcache.c	fix inode leaks on d_splice_alias() failure exits	2014-10-23 22:30:18 -04:00
dcookies.c
direct-io.c	fuse: honour max_read and max_write in direct_io mode	2014-09-26 21:16:51 -04:00
drop_caches.c
eventfd.c
eventpoll.c	eventpoll: fix uninitialized variable in epoll_ctl	2014-09-10 15:42:12 -07:00
exec.c	handle suicide on late failure exits in execve() in search_binary_handler()	2014-10-09 02:39:00 -04:00
fcntl.c	security: make security_file_set_fowner, f_setown and __f_setown void return	2014-09-09 16:01:36 -04:00
fhandle.c
file_table.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-10-13 11:28:42 +02:00
file.c	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-13 15:44:12 +02:00
filesystems.c
fs_pin.c	make fs/{namespace,super}.c forget about acct.h	2014-08-07 14:40:09 -04:00
fs_struct.c
fs-writeback.c	sched: Remove proliferation of wait_on_bit() action functions	2014-07-16 15:10:39 +02:00
inode.c	mm: allow drivers to prevent new writable mappings	2014-08-08 15:57:31 -07:00
internal.h	vfs: export __inode_permission() to modules	2014-10-24 00:14:35 +02:00
ioctl.c
Kconfig	overlay filesystem	2014-10-24 00:14:38 +02:00
Kconfig.binfmt
libfs.c	locks: plumb a "priv" pointer into the setlease routines	2014-10-07 14:06:12 -04:00
locks.c	locks: flock_make_lock should return a struct file_lock (or PTR_ERR)	2014-10-07 14:06:13 -04:00
Makefile	overlay filesystem	2014-10-24 00:14:38 +02:00
mbcache.c
mount.h	vfs: Add a function to lazily unmount all mounts from any dentry.	2014-10-09 02:38:55 -04:00
mpage.c	vfs: guard end of device for mpage interface	2014-10-09 22:25:53 -04:00
namei.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-11-02 10:28:43 -08:00
namespace.c	vfs: introduce clone_private_mount()	2014-10-24 00:14:36 +02:00
no-block.c
open.c	vfs: add i_op->dentry_open()	2014-10-24 00:14:35 +02:00
pipe.c
pnode.c	get rid of propagate_umount() mistakenly treating slaves as busy.	2014-08-30 18:31:41 -04:00
pnode.h
posix_acl.c
proc_namespace.c	namespaces: Use task_lock and not rcu to protect nsproxy	2014-07-29 18:08:50 -07:00
read_write.c	cachefiles_write_page(): switch to __kernel_write()	2014-10-09 02:39:05 -04:00
readdir.c
select.c
seq_file.c
signalfd.c
splice.c	vfs: export do_splice_direct() to modules	2014-10-24 00:14:35 +02:00
stack.c	fs: fix comment for 'CONFIG_LBADF'	2014-08-26 09:35:56 +02:00
stat.c
statfs.c
super.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-10-13 11:28:42 +02:00
sync.c	Export sync_filesystem() for modular ->remount_fs() use	2014-09-05 08:16:21 -07:00
timerfd.c	timerfd: Remove an always true check	2014-08-27 11:17:48 +02:00
utimes.c
xattr.c	vfs: Deduplicate code shared by xattr system calls operating on paths	2014-10-12 17:09:10 -04:00