Before this patch, glock_dq would call gfs2_glock_remove_from_lru.
For glocks that are never put on the LRU, such as the transaction
glock, this just takes the spin_lock, determines there's nothing to
be done because the list is empty, then unlocks again. This was
causing unnecessary lock contention on the lru_lock spin_lock.
This patch adds a check for GLOF_LRU in the glops before taking
the spin_lock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before commit 88ffbf3e03 "GFS2: Use resizable hash table for glocks",
glocks were freed via call_rcu to allow reading the glock hashtable
locklessly using rcu. This was then changed to free glocks immediately,
which made reading the glock hashtable unsafe. Bring back the original
code for freeing glocks via call_rcu.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Cc: stable@vger.kernel.org # 4.3+
This patch adds a standardized queueing mechanism for glock work
with spin_lock protection to prevent races.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This bug fixes a regression introduced by patch 0d1c7ae9d8.
The intent of the patch was to stop promoting glocks after a
file system is withdrawn due to a variety of errors, because doing
so results in a BUG(). (You should be able to unmount after a
withdraw rather than having the kernel panic.)
Unfortunately, it also stopped demotions, so glocks could not be
unlocked after withdraw, which means the unmount would hang.
This patch allows function do_xmote to demote locks to an
unlocked state after a withdraw, but not promote them.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Switch from rhashtable_lookup_insert_fast + rhashtable_lookup_fast to
rhashtable_lookup_get_insert_fast, which is cleaner and avoids an extra
rhashtable lookup.
At the same time, turn the retry loop in gfs2_glock_get into an infinite
loop. The lookup or insert will eventually succeed, usually very fast,
but there is no reason to give up trying at a fixed number of
iterations.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
As per a suggestion by Linus, don't pack struct lm_lockname: we did that
because the struct is used as a rhashtable key, but packing tells the
compiler that the 64-bit fields in the struct may be unaligned, causing
it to generate worse code on some architectures. Instead, rearrange the
fields in the struct so that there is no padding between fields, and
exclude any tail padding from the hash key size.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Both functions are identical except for the seq_operations used.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Function rhashtable_walk_init is deprecated.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
When the GFS2 file system withdraws due to metadata corruption, it
often has outstanding transactions in the journal and delayed work
queued for its glocks. This patch adds some new checks for a
withdrawn file system before proceeding with operations that would
obviously cause a BUG() to be triggered. That allows GFS2 to be
safely unmounted rather than cause the system to go down.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Andy Price wrote this patch to close a nasty race condition
that allows access to glocks that are being destroyed. Without
this patch, GFS2 is vulnerable to random corruption and kernel
panic.
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Merge tag 'gfs2-4.11.addendum' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull GFS2 fix from Bob Peterson:
"This is an addendum for the 4.11 merge window.
Andy Price wrote this patch to close a nasty race condition that
allows access to glocks that are being destroyed. Without this patch,
GFS2 is vulnerable to random corruption and kernel panic"
* tag 'gfs2-4.11.addendum' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Add missing rcu locking for glock lookup
We must hold the rcu read lock across looking up glocks and trying to
bump their refcount to prevent the glocks from being freed in between.
Cc: <stable@vger.kernel.org> # 4.3+
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Pull networking updates from David Miller:
"Highlights:
1) Support TX_RING in AF_PACKET TPACKET_V3 mode, from Sowmini
Varadhan.
2) Simplify classifier state on sk_buff in order to shrink it a bit.
From Willem de Bruijn.
3) Introduce SIPHASH and it's usage for secure sequence numbers and
syncookies. From Jason A. Donenfeld.
4) Reduce CPU usage for ICMP replies we are going to limit or
suppress, from Jesper Dangaard Brouer.
5) Introduce Shared Memory Communications socket layer, from Ursula
Braun.
6) Add RACK loss detection and allow it to actually trigger fast
recovery instead of just assisting after other algorithms have
triggered it. From Yuchung Cheng.
7) Add xmit_more and BQL support to mvneta driver, from Simon Guinot.
8) skb_cow_data avoidance in esp4 and esp6, from Steffen Klassert.
9) Export MPLS packet stats via netlink, from Robert Shearman.
10) Significantly improve inet port bind conflict handling, especially
when an application is restarted and changes it's setting of
reuseport. From Josef Bacik.
11) Implement TX batching in vhost_net, from Jason Wang.
12) Extend the dummy device so that VF (virtual function) features,
such as configuration, can be more easily tested. From Phil
Sutter.
13) Avoid two atomic ops per page on x86 in bnx2x driver, from Eric
Dumazet.
14) Add new bpf MAP, implementing a longest prefix match trie. From
Daniel Mack.
15) Packet sample offloading support in mlxsw driver, from Yotam Gigi.
16) Add new aquantia driver, from David VomLehn.
17) Add bpf tracepoints, from Daniel Borkmann.
18) Add support for port mirroring to b53 and bcm_sf2 drivers, from
Florian Fainelli.
19) Remove custom busy polling in many drivers, it is done in the core
networking since 4.5 times. From Eric Dumazet.
20) Support XDP adjust_head in virtio_net, from John Fastabend.
21) Fix several major holes in neighbour entry confirmation, from
Julian Anastasov.
22) Add XDP support to bnxt_en driver, from Michael Chan.
23) VXLAN offloads for enic driver, from Govindarajulu Varadarajan.
24) Add IPVTAP driver (IP-VLAN based tap driver) from Sainath Grandhi.
25) Support GRO in IPSEC protocols, from Steffen Klassert"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1764 commits)
Revert "ath10k: Search SMBIOS for OEM board file extension"
net: socket: fix recvmmsg not returning error from sock_error
bnxt_en: use eth_hw_addr_random()
bpf: fix unlocking of jited image when module ronx not set
arch: add ARCH_HAS_SET_MEMORY config
net: napi_watchdog() can use napi_schedule_irqoff()
tcp: Revert "tcp: tcp_probe: use spin_lock_bh()"
net/hsr: use eth_hw_addr_random()
net: mvpp2: enable building on 64-bit platforms
net: mvpp2: switch to build_skb() in the RX path
net: mvpp2: simplify MVPP2_PRS_RI_* definitions
net: mvpp2: fix indentation of MVPP2_EXT_GLOBAL_CTRL_DEFAULT
net: mvpp2: remove unused register definitions
net: mvpp2: simplify mvpp2_bm_bufs_add()
net: mvpp2: drop useless fields in mvpp2_bm_pool and related code
net: mvpp2: remove unused 'tx_skb' field of 'struct mvpp2_tx_queue'
net: mvpp2: release reference to txq_cpu[] entry after unmapping
net: mvpp2: handle too large value in mvpp2_rx_time_coal_set()
net: mvpp2: handle too large value handling in mvpp2_rx_pkts_coal_set()
net: mvpp2: remove useless arguments in mvpp2_rx_{pkts, time}_coal_set
...
1. Andy Price submitted a patch to make gfs2_write_full_page a
static function.
2. Dan Carpenter submitted a patch to fix a ERR_PTR thinko.
I've also got a few patches, three of which fix bugs related to
deleting very large files, which cause GFS2 to run out of
journal space:
3. The first one prevents GFS2 delete operation from requesting too
much journal space.
4. The second one fixes a problem whereby GFS2 can hang because it
wasn't taking journal space demand into its calculations.
5. The third one wakes up IO waiters when a flush is done to restart
processes stuck waiting for journal space to become available.
The other three patches are a performance improvement related to
spin_lock contention between multiple writers:
6. The "tr_touched" variable was switched to a flag to be more atomic
and eliminate the possibility of some races.
7. Function meta_lo_add was moved inline with its only caller to make
the code more readable and efficient.
8. Contention on the gfs2_log_lock spinlock was greatly reduced by
avoiding the lock altogether in cases where we don't really need
it: buffers that already appear in the appropriate metadata list
for the journal. Many thanks to Steve Whitehouse for the ideas and
principles behind these patches.
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Merge tag 'gfs2-4.11.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull GFS2 updates from Robert Peterson:
"We've got eight GFS2 patches for this merge window:
- Andy Price submitted a patch to make gfs2_write_full_page a static
function.
- Dan Carpenter submitted a patch to fix a ERR_PTR thinko.
Three patches fix bugs related to deleting very large files, which
cause GFS2 to run out of journal space:
- The first one prevents GFS2 delete operation from requesting too
much journal space.
- The second one fixes a problem whereby GFS2 can hang because it
wasn't taking journal space demand into its calculations.
- The third one wakes up IO waiters when a flush is done to restart
processes stuck waiting for journal space to become available.
The final three patches are a performance improvement related to
spin_lock contention between multiple writers:
- The "tr_touched" variable was switched to a flag to be more atomic
and eliminate the possibility of some races.
- Function meta_lo_add was moved inline with its only caller to make
the code more readable and efficient.
- Contention on the gfs2_log_lock spinlock was greatly reduced by
avoiding the lock altogether in cases where we don't really need
it: buffers that already appear in the appropriate metadata list
for the journal. Many thanks to Steve Whitehouse for the ideas and
principles behind these patches"
* tag 'gfs2-4.11.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Make gfs2_write_full_page static
GFS2: Reduce contention on gfs2_log_lock
GFS2: Inline function meta_lo_add
GFS2: Switch tr_touched to flag in transaction
GFS2: Wake up io waiters whenever a flush is done
GFS2: Made logd daemon take into account log demand
GFS2: Limit number of transaction blocks requested for truncates
GFS2: Fix reference to ERR_PTR in gfs2_glock_iter_next
The function glock_hash_walk walks the rhashtable by hand. This
is broken because if it catches the hash table in the middle of
a rehash, then it will miss entries.
This patch replaces the manual walk by using the rhashtable walk
interface.
Fixes: 88ffbf3e03 ("GFS2: Use resizable hash table for glocks")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes a place where function gfs2_glock_iter_next can
reference an invalid error pointer.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
register_shrinker can fail after commit 1d3d4437ea ("vmscan: per-node
deferred work"), we should detect the failure of it, otherwise we may
fail to register shrinker after gfs2 module was been inited successfully.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Replace 1 << value shift by more explicit BIT() macro
Also fixes two bare unsigned definitions:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
+ unsigned hsize = BIT(ip->i_depth);
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Make the code more readable by cleaning up the different ways of
initializing lock holders and checking for initialized lock holders:
mark lock holders as uninitialized by setting the holder's glock to NULL
(gfs2_holder_mark_uninitialized) instead of zeroing out the entire
object or using a separate flag. Recognize initialized holders by their
non-NULL glock (gfs2_holder_initialized). Don't zero out holder objects
which are immeditiately initialized via gfs2_holder_init or
gfs2_glock_nq_init.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Now that gfs2_lookup_by_inum only takes the inode glock for new inodes
(and not for cached inodes anymore), there no longer is a need to
optimize the cached-inode case in gfs2_get_dentry or delete_work_func,
and gfs2_ilookup can be removed.
In addition, gfs2_get_dentry wasn't checking the GFS2_DIF_SYSTEM flag in
i_diskflags in the gfs2_ilookup case (see gfs2_lookup_by_inum); this
inconsistency goes away as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
The current gfs2_lookup_by_inum takes the glock of a presumed inode
identified by block number, verifies that the block is indeed an inode,
and then instantiates and reads the new inode via gfs2_inode_lookup.
However, instantiating a new inode may block on freeing a previous
instance of that inode (__wait_on_freeing_inode), and freeing an inode
requires to take the glock already held, leading to lock inversion and
deadlock.
Fix this by first instantiating the new inode, then verifying that the
block is an inode (if required), and then reading in the new inode, all
in gfs2_inode_lookup.
If the block we are looking for is not an inode, we discard the new
inode via iget_failed, which marks inodes as bad and unhashes them.
Other tasks waiting on that inode will get back a bad inode back from
ilookup or iget_locked; in that case, retry the lookup.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
- Abhi Das has two patches that fix a GFS2 splice issue (and an adjustment).
- Ben Marzinski has a patch which allows the proper unmount of a GFS2
file system after hitting a withdraw error.
- I have a patch to fix a problem where GFS2 would dereference an error
value, plus three cosmetic / refactoring patches.
- Daniel DeFreez has a patch to fix two glock reference count problems,
where GFS2 was not properly "uninitializing" its glock holder on error
paths.
- Denys Vlasenko has a patch to change a function to not be inlined,
thus reducing the memory footprint of the GFS2 module.
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Merge tag 'gfs2-4.7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull GFS2 updates from Bob Peterson:
"We've got nine patches this time:
- Abhi Das has two patches that fix a GFS2 splice issue (and an
adjustment).
- Ben Marzinski has a patch which allows the proper unmount of a GFS2
file system after hitting a withdraw error.
- I have a patch to fix a problem where GFS2 would dereference an
error value, plus three cosmetic / refactoring patches.
- Daniel DeFreez has a patch to fix two glock reference count
problems, where GFS2 was not properly "uninitializing" its glock
holder on error paths.
- Denys Vlasenko has a patch to change a function to not be inlined,
thus reducing the memory footprint of the GFS2 module"
* tag 'gfs2-4.7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
GFS2: Refactor gfs2_remove_from_journal
GFS2: Remove allocation parms from gfs2_rbm_find
gfs2: use inode_lock/unlock instead of accessing i_mutex directly
GFS2: Add calls to gfs2_holder_uninit in two error handlers
GFS2: Don't dereference inode in gfs2_inode_lookup until it's valid
GFS2: fs/gfs2/glock.c: Deinline do_error, save 1856 bytes
gfs2: Use gfs2 wrapper to sync inode before calling generic_file_splice_read()
GFS2: Get rid of dead code in inode_go_demote_ok
GFS2: ignore unlock failures after withdraw
This function compiles to 522 bytes of machine code.
Error paths are not very time critical.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
In certain cases, the 802.11 mesh pathtable code wants to
iterate over all of the entries in the forwarding table from
the receive path, which is inside an RCU read-side critical
section. Enable walks inside atomic sections by allowing
GFP_ATOMIC allocations for the walker state.
Change all existing callsites to pass in GFP_KERNEL.
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
[also adjust gfs2/glock.c and rhashtable tests]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
After gfs2 has withdrawn the filesystem, it may still have many locks not
in the unlocked state. If it is using lock_dlm, it will failed trying
the unlocks since it has already unmounted the lock manager. Instead, it
should set the SDF_SKIP_DLM_UNLOCK flag on withdraw, to signal that
it can skip the lock_manager on unlocks, and failback to lock_nolock
style unlocking.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch basically reverts a very old patch from 2008,
7a9f53b3c1, with the title
"Alternate gfs2_iget to avoid looking up inodes being freed".
The original patch was designed to avoid a deadlock caused by lock
ordering with try_rgrp_unlink. The patch forced the function to not
find inodes that were being removed by VFS. The problem is, that
made it impossible for nodes to delete their own unlinked dinodes
after a certain point in time, because the inode needed was not found
by this filtering process. There is no longer a need for the patch,
since function try_rgrp_unlink no longer locks the inode: All it does
is queue the glock onto the delete work_queue, so there should be no
more deadlock.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch tries to prevent delete work (queued via iopen callback)
from executing if the glock is currently being used to create
a new inode.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
This patch fixes an error condition in which an inode is partially
created in gfs2_create_inode() but then some error is discovered,
which causes it to fail and call iput() before the iopen glock is
created or held. In that case, gfs2_delete_inode would try to
unlock an iopen glock that doesn't yet exist. Therefore, we test
its holder (which must exist) for the HIF_HOLDER bit before trying
to dq it.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
At some point in the past, we used to have a timeout when GFS2 was
unmounting, trying to clear out its glocks. If the timeout expires,
it would dump the remaining glocks to the kernel messages so that
developers can debug the problem. That timeout was eliminated,
probably by accident. This patch reintroduces it.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch makes no functional changes. Its goal is to reduce the
size of the gfs2 inode in memory by rearranging structures and
changing the size of some variables within the structure.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This lockdep splat was being triggered on umount:
[55715.973122] ===============================
[55715.980169] [ INFO: suspicious RCU usage. ]
[55715.981021] 4.3.0-11553-g8d3de01-dirty #15 Tainted: G W
[55715.982353] -------------------------------
[55715.983301] fs/gfs2/glock.c:1427 suspicious rcu_dereference_protected() usage!
The code it refers to is the rht_for_each_entry_safe usage in
glock_hash_walk. The condition that triggers the warning is
lockdep_rht_bucket_is_held(tbl, hash) which is checked in the
__rcu_dereference_protected macro.
The rhashtable buckets are not changed in glock_hash_walk so it's safe
to rely on the rcu protection. Replace the rht_for_each_entry_safe()
usage with rht_for_each_entry_rcu(), which doesn't care whether the
bucket lock is held if the rcu read lock is held.
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Commit e66cf161 replaced the gl_spin spinlock in struct gfs2_glock with a
gl_lockref lockref and defined gl_spin as gl_lockref.lock (the spinlock in
gl_lockref). Remove that define to make the references to gl_lockref.lock more
obvious.
Signed-off-by: Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
It seems cleaner to avoid the temporary value here.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
None of these statistics can meaningfully be negative, and the
numerator for do_div() must have the type u64. The generic
implementation of do_div() used on some 32-bit architectures asserts
that, resulting in a compiler error in gfs2_rgrp_congested().
Fixes: 0166b197c2 ("GFS2: Average in only non-zero round-trip times ...")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch changes the glock hash table from a normal hash table to
a resizable hash table, which scales better. This also simplifies
a lot of code.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
What uniquely identifies a glock in the glock hash table is not
gl_name, but gl_name and its superblock pointer. This patch makes
the gl_name field correspond to a unique glock identifier. That will
allow us to simplify hashing with a future patch, since the hash
algorithm can then take the gl_name and hash its components in one
operation.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Don't use struct gfs2_glock_iter as the helper data structure for iterating
through "sbstats"; we are not iterating through glocks here.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
The glocks used for resource groups often come and go hundreds of
thousands of times per second. Adding them to the lru list just
adds unnecessary contention for the lru_lock spin_lock, especially
considering we're almost certainly going to re-use the glock and
take it back off the lru microseconds later. We never want the
glock shrinker to cull them anyway. This patch adds a new bit in
the glops that determines which glock types get put onto the lru
list and which ones don't.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against ERROR_VALUE
as well, otherwise the later dereference of the dentry pointer would crash
the kernel.
Signed-off-by: Chengyu Song <csong84@gatech.edu>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Pull backing device changes from Jens Axboe:
"This contains a cleanup of how the backing device is handled, in
preparation for a rework of the life time rules. In this part, the
most important change is to split the unrelated nommu mmap flags from
it, but also removing a backing_dev_info pointer from the
address_space (and inode), and a cleanup of other various minor bits.
Christoph did all the work here, I just fixed an oops with pages that
have a swap backing. Arnd fixed a missing export, and Oleg killed the
lustre backing_dev_info from staging. Last patch was from Al,
unexporting parts that are now no longer needed outside"
* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
Make super_blocks and sb_lock static
mtd: export new mtd_mmap_capabilities
fs: make inode_to_bdi() handle NULL inode
staging/lustre/llite: get rid of backing_dev_info
fs: remove default_backing_dev_info
fs: don't reassign dirty inodes to default_backing_dev_info
nfs: don't call bdi_unregister
ceph: remove call to bdi_unregister
fs: remove mapping->backing_dev_info
fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
nilfs2: set up s_bdi like the generic mount_bdev code
block_dev: get bdev inode bdi directly from the block device
block_dev: only write bdev inode on close
fs: introduce f_op->mmap_capabilities for nommu mmap support
fs: kill BDI_CAP_SWAP_BACKED
fs: deduplicate noop_backing_dev_info
Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Since the only caller of function __gfs2_glock_remove_from_lru locks the
same spin_lock as gfs2_glock_remove_from_lru, the functions can be combined.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The functions iput() and put_pid() test whether their argument is NULL
and then return immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch allows flock glocks to use a non-blocking dequeue rather
than dq_wait. It also reverts the previous patch I had posted regarding
dq_wait. The reverted patch isn't necessarily a bad idea, but I decided
this might avoid unforeseen side effects, and was therefore safer.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Normally GFP_KERNEL is ok here, but there is now a rarely used code path
relating to deallocation of unlinked inodes (in certain corner cases)
which if hit at times of memory shortage can cause recursion while
trying to free memory.
One solution would be to try and move the gfs2_glock_get() call so
that it is no longer called while another glock is held, but that
doesn't look at all easy, so GFP_NOFS is the best solution for the
time being.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We must not leave items on the LRU list with GLF_LOCK set, since
they can be removed if the glock is brought back into use, which
may then potentially result in a hang, waiting for GLF_LOCK to
clear.
It doesn't happen very often, since it requires a glock that has
not been used for a long time to be brought back into use at the
same moment that the shrinker is part way through disposing of
glocks.
The fix is to set GLF_LOCK at a later time, when we already know
that the other locks can be obtained. Also, we now only release
the lru_lock in case a resched is needed, rather than on every
iteration.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Function gfs2_glock_dq_wait is supposed to dequeue a glock and then
wait for the lock to be demoted. The problem is, if this is a shared
lock, its demote will depend on the other holders, which means you
might end up waiting forever because the other process is blocked.
This problem is especially apparent when dealing with nested flocks.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Bob Peterson