12 Mar, 2013
1 commit
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Signed-off-by: Ionut-Gabriel Radu
Signed-off-by: Jan Kara
04 Mar, 2013
1 commit
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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
Acked-by: Kees Cook
Reported-by: Kees Cook
Signed-off-by: "Eric W. Biederman"
20 Nov, 2012
4 commits
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Calls into highlevel quota code cannot happen under the write lock. These
calls take dqio_mutex which ranks above write lock. So drop write lock
before calling back into quota code.CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara -
Calls into reiserfs journalling code and reiserfs_get_block() need to
be protected with write lock. We remove write lock around calls to high
level quota code in the next patch so these paths would suddently become
unprotected.CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara -
In reiserfs_quota_on() we do quite some work - for example unpacking
tail of a quota file. Thus we have to hold write lock until a moment
we call back into the quota code.CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara -
When remounting reiserfs dquot_suspend() or dquot_resume() can be called.
These functions take dqonoff_mutex which ranks above write lock so we have
to drop it before calling into quota code.CC: stable@vger.kernel.org # >= 3.0
Signed-off-by: Jan Kara
03 Oct, 2012
1 commit
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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
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Al Viro
23 Jul, 2012
1 commit
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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"
CC: Joel Becker
CC: reiserfs-devel@vger.kernel.org
Acked-by: Steven Whitehouse
Acked-by: Dave Kleikamp
Reviewed-by: Christoph Hellwig
Signed-off-by: Jan Kara
Signed-off-by: Al Viro
01 Jun, 2012
2 commits
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This patch stops reiserfs using the VFS 'write_super()' method along with the
s_dirt flag, because they are on their way out.The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblock using the '->write_super()' call-back. But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.Signed-off-by: Artem Bityutskiy
Signed-off-by: Al Viro -
We have the reiserfs superblock pointer in the 'sbi' variable in this
function, no need to use the 'REISERFS_SB(s)' macro which is the same.
This is jut a small clean-up.Signed-off-by: Artem Bityutskiy
Signed-off-by: Al Viro
16 May, 2012
1 commit
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We don't need i_mutex in reiserfs_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
21 Mar, 2012
4 commits
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Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
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Signed-off-by: Al Viro
11 Jan, 2012
3 commits
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Nothing requires that we lock the filesystem until the root inode is
provided.Also iget5_locked() triggers a warning because we are holding the
filesystem lock while allocating the inode, which result in a lockdep
suspicion that we have a lock inversion against the reclaim path:[ 1986.896979] =================================
[ 1986.896990] [ INFO: inconsistent lock state ]
[ 1986.896997] 3.1.1-main #8
[ 1986.897001] ---------------------------------
[ 1986.897007] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
[ 1986.897016] kswapd0/16 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 1986.897023] (&REISERFS_SB(s)->lock){+.+.?.}, at: [] reiserfs_write_lock+0x20/0x2a
[ 1986.897044] {RECLAIM_FS-ON-W} state was registered at:
[ 1986.897050] [] mark_held_locks+0xae/0xd0
[ 1986.897060] [] lockdep_trace_alloc+0x7d/0x91
[ 1986.897068] [] kmem_cache_alloc+0x1a/0x93
[ 1986.897078] [] reiserfs_alloc_inode+0x13/0x3d
[ 1986.897088] [] alloc_inode+0x14/0x5f
[ 1986.897097] [] iget5_locked+0x62/0x13a
[ 1986.897106] [] reiserfs_fill_super+0x410/0x8b9
[ 1986.897114] [] mount_bdev+0x10b/0x159
[ 1986.897123] [] get_super_block+0x10/0x12
[ 1986.897131] [] mount_fs+0x59/0x12d
[ 1986.897138] [] vfs_kern_mount+0x45/0x7a
[ 1986.897147] [] do_kern_mount+0x2f/0xb0
[ 1986.897155] [] do_mount+0x5c2/0x612
[ 1986.897163] [] sys_mount+0x61/0x8f
[ 1986.897170] [] sysenter_do_call+0x12/0x32
[ 1986.897181] irq event stamp: 7509691
[ 1986.897186] hardirqs last enabled at (7509691): [] kmem_cache_alloc+0x6e/0x93
[ 1986.897197] hardirqs last disabled at (7509690): [] kmem_cache_alloc+0x24/0x93
[ 1986.897209] softirqs last enabled at (7508896): [] __do_softirq+0xee/0xfd
[ 1986.897222] softirqs last disabled at (7508859): [] do_softirq+0x50/0x9d
[ 1986.897234]
[ 1986.897235] other info that might help us debug this:
[ 1986.897242] Possible unsafe locking scenario:
[ 1986.897244]
[ 1986.897250] CPU0
[ 1986.897254] ----
[ 1986.897257] lock(&REISERFS_SB(s)->lock);
[ 1986.897265]
[ 1986.897269] lock(&REISERFS_SB(s)->lock);
[ 1986.897276]
[ 1986.897277] *** DEADLOCK ***
[ 1986.897278]
[ 1986.897286] no locks held by kswapd0/16.
[ 1986.897291]
[ 1986.897292] stack backtrace:
[ 1986.897299] Pid: 16, comm: kswapd0 Not tainted 3.1.1-main #8
[ 1986.897306] Call Trace:
[ 1986.897314] [] ? printk+0xf/0x11
[ 1986.897324] [] print_usage_bug+0x20e/0x21a
[ 1986.897332] [] ? print_irq_inversion_bug+0x172/0x172
[ 1986.897341] [] mark_lock+0x27f/0x483
[ 1986.897349] [] __lock_acquire+0x628/0x1472
[ 1986.897358] [] lock_acquire+0x47/0x5e
[ 1986.897366] [] ? reiserfs_write_lock+0x20/0x2a
[ 1986.897384] [] ? reiserfs_write_lock+0x20/0x2a
[ 1986.897397] [] mutex_lock_nested+0x35/0x26f
[ 1986.897409] [] ? reiserfs_write_lock+0x20/0x2a
[ 1986.897421] [] reiserfs_write_lock+0x20/0x2a
[ 1986.897433] [] map_block_for_writepage+0xc9/0x590
[ 1986.897448] [] ? create_empty_buffers+0x33/0x8f
[ 1986.897461] [] ? get_parent_ip+0xb/0x31
[ 1986.897472] [] ? sub_preempt_count+0x81/0x8e
[ 1986.897485] [] ? _raw_spin_unlock+0x27/0x3d
[ 1986.897496] [] ? get_parent_ip+0xb/0x31
[ 1986.897508] [] reiserfs_writepage+0x1b9/0x3e7
[ 1986.897521] [] ? clear_page_dirty_for_io+0xcb/0xde
[ 1986.897533] [] ? trace_hardirqs_on_caller+0x108/0x138
[ 1986.897546] [] ? trace_hardirqs_on+0xb/0xd
[ 1986.897559] [] shrink_page_list+0x34f/0x5e2
[ 1986.897572] [] shrink_inactive_list+0x172/0x22c
[ 1986.897585] [] shrink_zone+0x303/0x3b1
[ 1986.897597] [] ? _raw_spin_unlock+0x27/0x3d
[ 1986.897611] [] kswapd+0x3b7/0x5f2The deadlock shouldn't happen since we are doing that allocation in the
mount path, the filesystem is not available for any reclaim. Still the
warning is annoying.To solve this, acquire the lock later only where we need it, right before
calling reiserfs_read_locked_inode() that wants to lock to walk the tree.Reported-by: Knut Petersen
Signed-off-by: Frederic Weisbecker
Cc: Al Viro
Cc: Christoph Hellwig
Cc: Jeff Mahoney
Cc: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
journal_init() doesn't need the lock since no operation on the filesystem
is involved there. journal_read() and get_list_bitmap() have yet to be
reviewed carefully though before removing the lock there. Just keep the
it around these two calls for safety.Signed-off-by: Frederic Weisbecker
Cc: Al Viro
Cc: Christoph Hellwig
Cc: Jeff Mahoney
Cc: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In the mount path, transactions that are made before journal
initialization don't involve the filesystem. We can delay the reiserfs
lock until we play with the journal.Signed-off-by: Frederic Weisbecker
Cc: Al Viro
Cc: Christoph Hellwig
Cc: Jeff Mahoney
Cc: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Jan, 2012
1 commit
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* '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
09 Jan, 2012
2 commits
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This patch fixes a crash in reiserfs_delete_xattrs during umount.
When shrink_dcache_for_umount clears the dcache from
generic_shutdown_super, delayed evictions are forced to disk. If an
evicted inode has extended attributes associated with it, it will
need to walk the xattr tree to locate and remove them.But since shrink_dcache_for_umount will BUG if it encounters active
dentries, the xattr tree must be released before it's called or it will
crash during every umount.This patch forces the evictions to occur before generic_shutdown_super
by calling shrink_dcache_sb first. The additional evictions caused
by the removal of each associated xattr file and dir will be automatically
handled as they're added to the LRU list.CC: reiserfs-devel@vger.kernel.org
CC: stable@kernel.org
Signed-off-by: Jeff Mahoney
Signed-off-by: Jan Kara -
When jqfmt mount option is not specified on remount, we mistakenly clear
s_jquota_fmt value stored in superblock. Fix the problem.CC: stable@kernel.org
CC: reiserfs-devel@vger.kernel.org
Signed-off-by: Jan Kara
07 Jan, 2012
2 commits
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Make reiserfs properly display mount options in /proc/mounts.
CC: reiserfs-devel@vger.kernel.org
Signed-off-by: Jan Kara
Signed-off-by: Al Viro -
Signed-off-by: Al Viro
04 Jan, 2012
1 commit
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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
21 Jul, 2011
1 commit
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Change the default reiserfs mount option to barrier=flush. Based on a patch
from Jeff Mahoney in the SuSE tree.Signed-off-by: Jeff Mahoney
Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
27 May, 2011
1 commit
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Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or
anything else, so that the filesystem can track internally if it
needs to push out a transaction for fdatasync or not.This is just the prototype change with no user for it yet. I plan
to push large XFS changes for the next merge window, and getting
this trivial infrastructure in this window would help a lot to avoid
tree interdependencies.Also remove incorrect comments that ->dirty_inode can't block. That
has been changed a long time ago, and many implementations rely on it.Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
31 Mar, 2011
1 commit
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Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi
13 Jan, 2011
1 commit
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As Al Viro pointed out path resolution during Q_QUOTAON calls to quotactl
is prone to deadlocks. We hold s_umount semaphore for reading during the
path resolution and resolution itself may need to acquire the semaphore
for writing when e. g. autofs mountpoint is passed.Solve the problem by performing the resolution before we get hold of the
superblock (and thus s_umount semaphore). The whole thing is complicated
by the fact that some filesystems (OCFS2) ignore the path argument. So to
distinguish between filesystem which want the path and which do not we
introduce new .quota_on_meta callback which does not get the path. OCFS2
then uses this callback instead of old .quota_on.CC: Al Viro
CC: Christoph Hellwig
CC: Ted Ts'o
CC: Joel Becker
Signed-off-by: Jan Kara
07 Jan, 2011
1 commit
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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
18 Nov, 2010
1 commit
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The big kernel lock has been removed from all these files at some point,
leaving only the #include.Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann
Signed-off-by: Linus Torvalds
29 Oct, 2010
1 commit
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... and switch of the obvious get_sb_bdev() users to ->mount()
Signed-off-by: Al Viro
10 Aug, 2010
2 commits
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Signed-off-by: Al Viro
-
a) count file openers correctly; i_count use was completely wrong
b) use new mutex for exclusion between final close/open/truncate,
to protect tailpacking logics. i_mutex use was wrong and resulted
in deadlocks.Signed-off-by: Al Viro
27 May, 2010
1 commit
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When quota was suspended on remount-ro, finish_unfinished() will try to turn
it on again (which fails) and also turns the quotas off on exit. Fix the
function to check whether quotas are already on at function entry and do
not turn them off in that case.CC: reiserfs-devel@vger.kernel.org
Signed-off-by: Jan Kara
24 May, 2010
5 commits
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Follow the dquot_* style used elsewhere in dquot.c.
[Jan Kara: Fixed up missing conversion of ext2]
Signed-off-by: Christoph Hellwig
Signed-off-by: Jan Kara -
Remount handling has fully moved into the filesystem, so all this is
superflous now.Signed-off-by: Christoph Hellwig
Signed-off-by: Jan Kara -
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
Signed-off-by: Jan Kara -
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
Signed-off-by: Jan Kara -
Currently do_remount_sb calls into the dquot code to tell it about going
from rw to ro and ro to rw. Move this code into the filesystem to
not depend on the dquot code in the VFS - note ocfs2 already ignores
these calls and handles remount by itself. This gets rid of overloading
the quotactl calls and allows to unify the VFS and XFS codepaths in
that area later.Signed-off-by: Christoph Hellwig
Signed-off-by: Jan Kara
05 Apr, 2010
1 commit
