FS_CGROUP_WRITEBACK indicates whether a file_system_type supports
cgroup writeback; however, different super_blocks of the same
file_system_type may or may not support cgroup writeback depending on
filesystem options. This patch replaces FS_CGROUP_WRITEBACK with a
per-super_block flag.
super_block->s_flags carries some internal flags in the high bits but
it's exposd to userland through uapi header and running out of space
anyway. This patch adds a new field super_block->s_iflags to carry
kernel-internal flags. It is currently only used by the new
SB_I_CGROUPWB flag whose concatenated and abbreviated name is for
consistency with other super_block flags.
ext2_fill_super() is updated to set SB_I_CGROUPWB.
v2: Added super_block->s_iflags instead of stealing another high bit
from sb->s_flags as suggested by Christoph and Jan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Writeback now supports cgroup writeback and the generic writeback,
buffer, libfs, and mpage helpers that ext2 uses are all updated to
work with cgroup writeback.
This patch enables cgroup writeback for ext2 by adding
FS_CGROUP_WRITEBACK to its ->fs_flags.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
To help people transition, accept the 'xip' mount option (and report it in
/proc/mounts), but print a message encouraging people to switch over to
the 'dax' option.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The fewer Kconfig options we have the better. Use the generic
CONFIG_FS_DAX to enable XIP support in ext2 as well as in the core.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These files are now empty, so delete them
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara pointed out that calling ext2_xip_verify_sb() in ext2_remount()
doesn't make sense, since changing the XIP option on remount isn't
allowed. It also doesn't make sense to re-check whether blocksize is
supported since it can't change between mounts.
Replace the call to ext2_xip_verify_sb() in ext2_fill_super() with the
equivalent check and delete the definition.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Percpu allocator now supports allocation mask. Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.
We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion. This is the one with
the most users. Other percpu data structures are a lot easier to
convert.
This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: x86@kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Drop cast on the result of kmem_cache_alloc.
The semantic patch that makes this change is as follows:
// <smpl>
@@
type T;
@@
- (T *)
(\(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|
kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\)(...))
// </smpl>
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Jan Kara <jack@suse.cz>
Pull ext3 improvements, cleanups, reiserfs fix from Jan Kara:
"various cleanups for ext2, ext3, udf, isofs, a documentation update
for quota, and a fix of a race in reiserfs readdir implementation"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
reiserfs: fix race in readdir
ext2: acl: remove unneeded include of linux/capability.h
ext3: explicitly remove inode from orphan list after failed direct io
fs/isofs/inode.c add __init to init_inodecache()
ext3: Speedup WB_SYNC_ALL pass
fs/quota/Kconfig: Update filesystems
ext3: Update outdated comment before ext3_ordered_writepage()
ext3: Update PF_MEMALLOC handling in ext3_write_inode()
ext2/3: use prandom_u32() instead of get_random_bytes()
ext3: remove an unneeded check in ext3_new_blocks()
ext3: remove unneeded check in ext3_ordered_writepage()
fs: Mark function as static in ext3/xattr_security.c
fs: Mark function as static in ext3/dir.c
fs: Mark function as static in ext2/xattr_security.c
ext3: Add __init macro to init_inodecache
ext2: Add __init macro to init_inodecache
udf: Add __init macro to init_inodecache
fs: udf: parse_options: blocksize check
ext2_quota_write() doesn't properly setup bh it passes to
ext2_get_block() and thus we hit assertion BUG_ON(maxblocks == 0) in
ext2_get_blocks() (or we could actually ask for mapping arbitrary number
of blocks depending on whatever value was on stack).
Fix ext2_quota_write() to properly fill in number of blocks to map.
CC: stable@vger.kernel.org # >= 2.6.12
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.
A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.
Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.
Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.
This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.
This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.
After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Because the function 'sb_getblk' seldomly fails to return
NULL value. It will be better to use unlikely to optimize it.
Signed-off-by: Wang shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
parse_options() in ext2 should return 0 when parse the mount options fails.
Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
There's no reason to call rcu_barrier() on every
deactivate_locked_super(). We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.
Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths. E.g. on my machine exit_group() of a last process in IPC
namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull second vfs pile from Al Viro:
"The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
deadlock reproduced by xfstests 068), symlink and hardlink restriction
patches, plus assorted cleanups and fixes.
Note that another fsfreeze deadlock (emergency thaw one) is *not*
dealt with - the series by Fernando conflicts a lot with Jan's, breaks
userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
for massive vfsmount leak; this is going to be handled next cycle.
There probably will be another pull request, but that stuff won't be
in it."
Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
delousing target_core_file a bit
Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
fs: Remove old freezing mechanism
ext2: Implement freezing
btrfs: Convert to new freezing mechanism
nilfs2: Convert to new freezing mechanism
ntfs: Convert to new freezing mechanism
fuse: Convert to new freezing mechanism
gfs2: Convert to new freezing mechanism
ocfs2: Convert to new freezing mechanism
xfs: Convert to new freezing code
ext4: Convert to new freezing mechanism
fs: Protect write paths by sb_start_write - sb_end_write
fs: Skip atime update on frozen filesystem
fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
fs: Improve filesystem freezing handling
switch the protection of percpu_counter list to spinlock
nfsd: Push mnt_want_write() outside of i_mutex
btrfs: Push mnt_want_write() outside of i_mutex
fat: Push mnt_want_write() outside of i_mutex
...
The only missing piece to make freezing work reliably with ext2 is to
stop iput() of unlinked inode from deleting the inode on frozen filesystem.
So add a necessary protection to ext2_evict_inode().
We also provide appropriate ->freeze_fs and ->unfreeze_fs functions.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull misc udf, ext2, ext3, and isofs fixes from Jan Kara:
"Assorted, mostly trivial, fixes for udf, ext2, ext3, and isofs. I'm
on vacation and scarcely checking email since we are expecting baby
any day now but these fixes should be safe to go in and I don't want
to delay them unnecessarily."
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
udf: avoid info leak on export
isofs: avoid info leak on export
udf: Improve table length check to avoid possible overflow
ext3: Check return value of blkdev_issue_flush()
jbd: Check return value of blkdev_issue_flush()
udf: Do not decrement i_blocks when freeing indirect extent block
udf: Fix memory leak when mounting
ext2: cleanup the confused goto label
UDF: Remove unnecessary variable "offset" from udf_fill_inode
udf: stop using s_dirt
ext3: force ro mount if ext3_setup_super() fails
quota: fix checkpatch.pl warning by replacing <asm/uaccess.h> with <linux/uaccess.h>
Since the moment writes to quota files are using block device page cache and
space for quota structures is reserved at the moment they are first accessed we
have no reason to sync quota before inode writeback. In fact this order is now
only harmful since quota information can easily change during inode writeback
(either because conversion of delayed-allocated extents or simply because of
allocation of new blocks for simple filesystems not using page_mkwrite).
So move syncing of quota information after writeback of inodes into ->sync_fs
method. This way we do not have to use ->quota_sync callback which is primarily
intended for use by quotactl syscall anyway and we get rid of calling
->sync_fs() twice unnecessarily. We skip quota syncing for OCFS2 since it does
proper quota journalling in all cases (unlike ext3, ext4, and reiserfs which
also support legacy non-journalled quotas) and thus there are no dirty quota
structures.
CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Joel Becker <jlbec@evilplan.org>
CC: reiserfs-devel@vger.kernel.org
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Dave Kleikamp <shaggy@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cleanup the confused goto label, since the big lock has been removed.
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Pull ext2, ext3 and quota fixes from Jan Kara:
"Interesting bits are:
- removal of a special i_mutex locking subclass (I_MUTEX_QUOTA) since
quota code does not need i_mutex anymore in any unusual way.
- backport (from ext4) of a fix of a checkpointing bug (missing cache
flush) that could lead to fs corruption on power failure
The rest are just random small fixes & cleanups."
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2: trivial fix to comment for ext2_free_blocks
ext2: remove the redundant comment for ext2_export_ops
ext3: return 32/64-bit dir name hash according to usage type
quota: Get rid of nested I_MUTEX_QUOTA locking subclass
quota: Use precomputed value of sb_dqopt in dquot_quota_sync
ext2: Remove i_mutex use from ext2_quota_write()
reiserfs: Remove i_mutex use from reiserfs_quota_write()
ext4: Remove i_mutex use from ext4_quota_write()
ext3: Remove i_mutex use from ext3_quota_write()
quota: Fix double lock in add_dquot_ref() with CONFIG_QUOTA_DEBUG
jbd: Write journal superblock with WRITE_FUA after checkpointing
jbd: protect all log tail updates with j_checkpoint_mutex
jbd: Split updating of journal superblock and marking journal empty
ext2: do not register write_super within VFS
ext2: Remove s_dirt handling
ext2: write superblock only once on unmount
ext3: update documentation with barrier=1 default
ext3: remove max_debt in find_group_orlov()
jbd: Refine commit writeout logic
The comment is outdated and isn't particularly informative anyway - NULL
meaning the default behavior is very common in kernel. And we really set about
half of entries. So remove the whole comment for ext2_export_ops.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
We don't need i_mutex in ext2_quota_write() because writes to quota file
are serialized by dqio_mutex anyway. Changes to quota files outside of quota
code are forbidded and enforced by NOATIME and IMMUTABLE bits.
Signed-off-by: Jan Kara <jack@suse.cz>
Jan Kara removed 'sb->s_dirt' VFS flag references, so we do not need to
register the ext2 'ext2_write_super()' method in the VFS superblock operations,
because 'sb->s_dirt' won't be ever set to 1 and VFS won't ever call
'->write_super()' anyway. Thus, remove the method.
Tested using xfstests.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Places which modify superblock feature / state fields mark the superblock
buffer dirty so it is written out by flusher thread. Thus there's no need to
set s_dirt there.
The only other fields changing in the superblock are the numbers of free
blocks, free inodes and s_wtime. There's no real need to write (or even
compute) these periodically. Free blocks / inodes counters are recomputed on
every mount from group counters anyway and value of s_wtime is only
informational and imprecise anyway. So it should be enough to write these
opportunistically on mount, remount, umount, and sync_fs times.
Signed-off-by: Jan Kara <jack@suse.cz>
Currently on unmount if we are mounted R/W, we first write the superblock to
the media if it is dirty, and then write it again, which is not optimal. This
patch makes ext2 write the superblock on unmount less times.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
New field of struct super_block - ->s_max_links. Maximal allowed
value of ->i_nlink or 0; in the latter case all checks still need
to be done in ->link/->mkdir/->rename instances. Note that this
limit applies both to directoris and to non-directories.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2/3/4: delete unneeded includes of module.h
ext{3,4}: Fix potential race when setversion ioctl updates inode
udf: Mark LVID buffer as uptodate before marking it dirty
ext3: Don't warn from writepage when readonly inode is spotted after error
jbd: Remove j_barrier mutex
reiserfs: Force inode evictions before umount to avoid crash
reiserfs: Fix quota mount option parsing
udf: Treat symlink component of type 2 as /
udf: Fix deadlock when converting file from in-ICB one to normal one
udf: Cleanup calling convention of inode_getblk()
ext2: Fix error handling on inode bitmap corruption
ext3: Fix error handling on inode bitmap corruption
ext3: replace ll_rw_block with other functions
ext3: NULL dereference in ext3_evict_inode()
jbd: clear revoked flag on buffers before a new transaction started
ext3: call ext3_mark_recovery_complete() when recovery is really needed
Delete any instances of include module.h that were not strictly
required. In the case of ext2, the declaration of MODULE_LICENSE
etc. were in inode.c but the module_init/exit were in super.c, so
relocate the MODULE_LICENCE/AUTHOR block to super.c which makes it
consistent with ext3 and ext4 at the same time.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When ext2 mounts a filesystem, it attempts to set the block device
blocksize with a call to sb_set_blocksize, which can fail for
several reasons. The current failure message in ext2 prints:
EXT2-fs (loop1): error: blocksize is too small
which is not correct in all cases. This can be demonstrated
by creating a filesystem with
# mkfs.ext2 -b 8192
on a 4k page system, and attempting to mount it.
Change the error message to a more generic:
EXT2-fs (loop1): bad blocksize 8192
to match the error message in ext3.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Reviewed-by: Coly Li <bosong.ly@taobao.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
ext2: Resolve 'dereferencing pointer to incomplete type' when enabling EXT2_XATTR_DEBUG
ext3: Remove redundant unlikely()
ext2: Remove redundant unlikely()
ext3: speed up file creates by optimizing rec_len functions
ext2: speed up file creates by optimizing rec_len functions
ext3: Add more journal error check
ext3: Add journal error check in resize.c
quota: Use %pV and __attribute__((format (printf in __quota_error and fix fallout
ext3: Add FITRIM handling
ext3: Add batched discard support for ext3
ext3: Add journal error check into ext3_rename()
ext3: Use search_dirblock() in ext3_dx_find_entry()
ext3: Avoid uninitialized memory references with a corrupted htree directory
ext3: Return error code from generic_check_addressable
ext3: Add journal error check into ext3_delete_entry()
ext3: Add error check in ext3_mkdir()
fs/ext3/super.c: Use printf extension %pV
fs/ext2/super.c: Use printf extension %pV
ext3: don't update sb journal_devnum when RO dev
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Using %pV reduces the number of printk calls and
eliminates any possible message interleaving from
other printk calls.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jan Kara <jack@suse.cz>
It's pointless - we *do* have busy inodes (root directory,
for one), so that call will fail and attempt to change
XIP flag will be ignored.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The BKL is still used in ext2_put_super(), ext2_fill_super(), ext2_sync_fs()
ext2_remount() and ext2_write_inode(). From these calls ext2_put_super(),
ext2_fill_super() and ext2_remount() are protected against each other by
the struct super_block s_umount rw semaphore. The call in ext2_write_inode()
could only protect the modification of the ext2_sb_info through
ext2_update_dynamic_rev() against concurrent ext2_sync_fs() or ext2_remount().
ext2_fill_super() and ext2_put_super() can be left out because you need a
valid filesystem reference in all three cases, which you do not have when
you are one of these functions.
If the BKL is only protecting the modification of the ext2_sb_info it can
safely be removed since this is protected by the struct ext2_sb_info s_lock.
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.
I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.
do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.
Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.
[arnd: do not add the BKL to those file systems that already
don't use it elsewhere]
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Follow the dquot_* style used elsewhere in dquot.c.
[Jan Kara: Fixed up missing conversion of ext2]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Only set the quota operation vectors if the filesystem actually supports
quota instead of doing it for all filesystems in alloc_super().
[Jan Kara: Export dquot_operations and vfs_quotactl_ops]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Currently the VFS calls into the quotactl interface for unmounting
filesystems. This means filesystems with their own quota handling
can't easily distinguish between user-space originating quotaoff
and an unount. Instead move the responsibily of the unmount handling
into the filesystem to be consistent with all other dquot handling.
Note that we do call dquot_disable a lot later now, e.g. after
a sync_filesystem. But this is fine as the quota code does all its
writes via blockdev's mapping and that is synced even later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Instead of having wrappers in the VFS namespace export the dquot_suspend
and dquot_resume helpers directly. Also rename vfs_quota_disable to
dquot_disable while we're at it.
[Jan Kara: Moved dquot_suspend to quotaops.h and made it inline]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
