- 05 Feb, 2015 12 commits
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NeilBrown authored
Rather than using mddev_lock() to take the reconfig_mutex when writing to any md sysfs file, we only take mddev_lock() in the particular _store() functions that require it. Admittedly this is most, but it isn't all. This also allows us to remove special-case handling for new_dev_store (in md_attr_store). Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
The one which is not inline (mddev_unlock) gets EXPORTed. This makes the locking available to personality modules so that it doesn't have to be imposed upon them. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
There are interdependencies between these two sysfs attributes and whether a resync is currently running. Rather than depending on reconfig_mutex to ensure no races when testing these interdependencies are met, use the spinlock. This will allow the mutex to be remove from protecting this code in a subsequent patch. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
There isn't really much room for races with ->safemode_delay. But as I am trying to clean up any racy code and will soon be removing reconfig_mutex protection from most _store() functions: - only set mddev->safemode_delay once, to ensure no code can see an intermediate value - use safemode_timer to call md_safemode_timeout() rather than calling it directly, to ensure it never races with itself. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
It makes more sense to report bitmap_info->file, rather than bitmap->file (the later is only available once the array is active). With that change, use mddev->lock to protect bitmap_info being set to NULL, and we can call get_bitmap_file() without taking the mutex. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
1/ delay setting mddev->bitmap_info.file until 'f' looks usable, so we don't have to unset it. 2/ Don't allow bitmap file to be set if bitmap_info.file is already set. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
'buf' is only used because d_path fills from the end of the buffer instead of from the start. We don't need a separate buf to handle that, we just need to use memmove() to move the string to the start. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
No rdev attributes need locking for 'show', though state_show() might benefit from ensuring it sees a consistent set of flags. None even use rdev->mddev, so testing for it isn't really needed and it certainly doesn't need to be held constant. So improve state_show() and remove the locking. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
Most attributes can be read safely without any locking. A race might lead to a slightly out-dated value, but nothing wrong. We already have locking in some places where needed. All that remains is can_clear_show(), behind_writes_used_show() and action_show() which are easily fixed. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
It is important that mddev->private isn't freed while a sysfs attribute function is accessing it. So use mddev->lock to protect the setting of ->private to NULL, and take that lock when checking ->private for NULL and de-referencing it in the sysfs access functions. This only applies to the read ('show') side of access. Write access will be handled separately. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
The only access in md_seq_show that could suffer from races not protected by ->lock is walking the rdev list. This can receive sufficient protection from 'rcu'. So use rdev_for_each_rcu() and get rid of mddev_lock(). Now reading /proc/mdstat will never block in md_seq_show. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
This makes it safe to inspect the struct while holding only the spinlock. Signed-off-by: NeilBrown <neilb@suse.de>
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- 03 Feb, 2015 14 commits
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NeilBrown authored
->pers is already protected by ->reconfig_mutex, and cannot possibly change when there are threads running or outstanding IO. However there are some places where we access ->pers not in a thread or IO context, and where ->reconfig_mutex is unnecessarily heavy-weight: level_show and md_seq_show(). So protect all changes, and those accesses, with ->lock. This is a step toward taking those accesses out from under reconfig_mutex. [Fixed missing "mddev->pers" -> "pers" conversion, thanks to Dan Carpenter <dan.carpenter@oracle.com>] Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
Gather all the changes that can happen atomically and might be relevant to other code into one place. This will make it easier to refine the locking. Note that this puts quite a few things between mddev_detach() and ->free(). Enabling this was the point of some recent patches. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
Now that the ->stop function only frees the private data, rename is accordingly. Also pass in the private pointer as an arg rather than using mddev->private. This flexibility will be useful in level_store(). Finally, don't clear ->private. It doesn't make sense to clear it seeing that isn't what we free, and it is no longer necessary to clear ->private (it was some time ago before ->to_remove was introduced). Setting ->to_remove in ->free() is a bit of a wart, but not a big problem at the moment. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
Each md personality has a 'stop' operation which does two things: 1/ it finalizes some aspects of the array to ensure nothing is accessing the ->private data 2/ it frees the ->private data. All the steps in '1' can apply to all arrays and so can be performed in common code. This is useful as in the case where we change the personality which manages an array (in level_store()), it would be helpful to do step 1 early, and step 2 later. So split the 'step 1' functionality out into a new mddev_detach(). Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
The use of 'rcu' to protect accesses to ->private_data so that the ->private_data could be updated predates the introduction of mddev_suspend/mddev_resume. These are a cleaner mechanism for providing stability while swapping in a new ->private data - it is used by level_store() to support changing of raid levels. So get rid of the RCU stuff and just use mddev_suspend, mddev_resume. As these function call ->quiesce(), we add an empty function for linear just like for raid0. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
There is no locking around calls to merge_bvec_fn(), so it is possible that calls which coincide with a level (or personality) change could go wrong. So create a central dispatch point for these functions and use rcu_read_lock(). If the array is suspended, reject any merge that can be rejected. If not, we know it is safe to call the function. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
There is currently no locking around calls to the 'congested' bdi function. If called at an awkward time while an array is being converted from one level (or personality) to another, there is a tiny chance of running code in an unreferenced module etc. So add a 'congested' function to the md_personality operations structure, and call it with appropriate locking from a central 'mddev_congested'. When the array personality is changing the array will be 'suspended' so no IO is processed. If mddev_congested detects this, it simply reports that the array is congested, which is a safe guess. As mddev_suspend calls synchronize_rcu(), mddev_congested can avoid races by included the whole call inside an rcu_read_lock() region. This require that the congested functions for all subordinate devices can be run under rcu_lock. Fortunately this is the case. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
This lock is used for (slightly) more than helping with writing superblocks, and it will soon be extended further. So the name is inappropriate. Also, the _irq variant hasn't been needed since 2.6.37 as it is never taking from interrupt or bh context. So: -rename write_lock to lock -document what it protects -remove _irq ... except in md_flush_request() as there is no wait_event_lock() (with no _irq). This can be cleaned up after appropriate changes to wait.h. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
That last condition is unclear and over cautious. There are two related issues here. If a partial write is destined for a missing device, then either RMW or RCW can work. We must read all the available block. Only then can the missing blocks be calculated, and then the parity update performed. If RMW is not an option, then there is a complication even without partial writes. If we would need to read a missing device to perform the reconstruction, then we must first read every block so the missing device data can be computed. This is the case for RAID6 (Which currently does not support RMW) and for times when we don't trust the parity (after a crash) and so are in the process of resyncing it. So make these two cases more clear and separate, and perform the relevant tests more thoroughly. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
Both the last two cases are only relevant if something has failed and something needs to be written (but not over-written), and if it is OK to pre-read blocks at this point. So factor out those tests and explain them. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
Some of the conditions in need_this_block have very straight forward motivation. Separate those out and document them. Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
fetch_block() has a very large and hard to read 'if' condition. Separate it into its own function so that it can be made more readable. Signed-off-by: NeilBrown <neilb@suse.de>
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Jes Sorensen authored
67f45548 introduced a call to md_wakeup_thread() when adding to the delayed_list. However the md thread is woken up unconditionally just below. Remove the unnecessary wakeup call. Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
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Jan Beulich authored
Just like for AVX2 (which simply needs an #if -> #ifdef conversion), SSSE3 assembler support should be checked for before using it. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NeilBrown <neilb@suse.de>
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- 02 Feb, 2015 2 commits
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NeilBrown authored
commit 8eb23b9f sched: Debug nested sleeps causes false-positive warnings in RAID5 code. This annotation removes them and adds a comment explaining why there is no real problem. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
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NeilBrown authored
If a non-page-aligned write is destined for a device which is missing/faulty, we can deadlock. As the target device is missing, a read-modify-write cycle is not possible. As the write is not for a full-page, a recontruct-write cycle is not possible. This should be handled by logic in fetch_block() which notices there is a non-R5_OVERWRITE write to a missing device, and so loads all blocks. However since commit 67f45548, that code requires STRIPE_PREREAD_ACTIVE before it will active, and those circumstances never set STRIPE_PREREAD_ACTIVE. So: in handle_stripe_dirtying, if neither rmw or rcw was possible, set STRIPE_DELAYED, which will cause STRIPE_PREREAD_ACTIVE be set after a suitable delay. Fixes: 67f45548 Cc: stable@vger.kernel.org (v3.16+) Reported-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
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- 27 Jan, 2015 12 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds authored
Pull networking fixes from David Miller: 1) Don't OOPS on socket AIO, from Christoph Hellwig. 2) Scheduled scans should be aborted upon RFKILL, from Emmanuel Grumbach. 3) Fix sleep in atomic context in kvaser_usb, from Ahmed S Darwish. 4) Fix RCU locking across copy_to_user() in bpf code, from Alexei Starovoitov. 5) Lots of crash, memory leak, short TX packet et al bug fixes in sh_eth from Ben Hutchings. 6) Fix memory corruption in SCTP wrt. INIT collitions, from Daniel Borkmann. 7) Fix return value logic for poll handlers in netxen, enic, and bnx2x. From Eric Dumazet and Govindarajulu Varadarajan. 8) Header length calculation fix in mac80211 from Fred Chou. 9) mv643xx_eth doesn't handle highmem correctly in non-TSO code paths. From Ezequiel Garcia. 10) udp_diag has bogus logic in it's hash chain skipping, copy same fix tcp diag used. From Herbert Xu. 11) amd-xgbe programs wrong rx flow control register, from Thomas Lendacky. 12) Fix race leading to use after free in ping receive path, from Subash Abhinov Kasiviswanathan. 13) Cache redirect routes otherwise we can get a heavy backlog of rcu jobs liberating DST_NOCACHE entries. From Hannes Frederic Sowa. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (48 commits) net: don't OOPS on socket aio stmmac: prevent probe drivers to crash kernel bnx2x: fix napi poll return value for repoll ipv6: replacing a rt6_info needs to purge possible propagated rt6_infos too sh_eth: Fix DMA-API usage for RX buffers sh_eth: Check for DMA mapping errors on transmit sh_eth: Ensure DMA engines are stopped before freeing buffers sh_eth: Remove RX overflow log messages ping: Fix race in free in receive path udp_diag: Fix socket skipping within chain can: kvaser_usb: Fix state handling upon BUS_ERROR events can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT can: kvaser_usb: Send correct context to URB completion can: kvaser_usb: Do not sleep in atomic context ipv4: try to cache dst_entries which would cause a redirect samples: bpf: relax test_maps check bpf: rcu lock must not be held when calling copy_to_user() net: sctp: fix slab corruption from use after free on INIT collisions net: mv643xx_eth: Fix highmem support in non-TSO egress path sh_eth: Fix serialisation of interrupt disable with interrupt & NAPI handlers ...
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Christoph Hellwig authored
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
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Andy Shevchenko authored
In the case when alloc_netdev fails we return NULL to a caller. But there is no check for NULL in the probe drivers. This patch changes NULL to an error pointer. The function description is amended to reflect what we may get returned. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linuxLinus Torvalds authored
Pull powerpc fixes from Michael Ellerman: "Two powerpc fixes" * tag 'powerpc-3.19-5' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: powerpc/powernv: Restore LPCR with LPCR_PECE1 cleared powerpc/xmon: Fix another endiannes issue in RTAS call from xmon
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git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linuxLinus Torvalds authored
Pull one more module fix from Rusty Russell: "SCSI was using module_refcount() to figure out when the module was unloading: this broke with new atomic refcounting. The code is still suspicious, but this solves the WARN_ON()" * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: scsi: always increment reference count
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Govindarajulu Varadarajan authored
With the commit d75b1ade ("net: less interrupt masking in NAPI") napi repoll is done only when work_done == budget. When in busy_poll is we return 0 in napi_poll. We should return budget. Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsecDavid S. Miller authored
Steffen Klassert says: ==================== ipsec 2015-01-26 Just two small fixes for _decode_session6() where we might decode to wrong header information in some rare situations. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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Hannes Frederic Sowa authored
Lubomir Rintel reported that during replacing a route the interface reference counter isn't correctly decremented. To quote bug <https://bugzilla.kernel.org/show_bug.cgi?id=91941>: | [root@rhel7-5 lkundrak]# sh -x lal | + ip link add dev0 type dummy | + ip link set dev0 up | + ip link add dev1 type dummy | + ip link set dev1 up | + ip addr add 2001:db8:8086::2/64 dev dev0 | + ip route add 2001:db8:8086::/48 dev dev0 proto static metric 20 | + ip route add 2001:db8:8088::/48 dev dev1 proto static metric 10 | + ip route replace 2001:db8:8086::/48 dev dev1 proto static metric 20 | + ip link del dev0 type dummy | Message from syslogd@rhel7-5 at Jan 23 10:54:41 ... | kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2 | | Message from syslogd@rhel7-5 at Jan 23 10:54:51 ... | kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2 During replacement of a rt6_info we must walk all parent nodes and check if the to be replaced rt6_info got propagated. If so, replace it with an alive one. Fixes: 4a287eba ("IPv6 routing, NLM_F_* flag support: REPLACE and EXCL flags support, warn about missing CREATE flag") Reported-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Tested-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller authored
Ben Hutchings says: ==================== Fixes for sh_eth #3 I'm continuing review and testing of Ethernet support on the R-Car H2 chip. This series fixes the last of the more serious issues I've found. These are not tested on any of the other supported chips. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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Ben Hutchings authored
- Use the return value of dma_map_single(), rather than calling virt_to_page() separately - Check for mapping failue - Call dma_unmap_single() rather than dma_sync_single_for_cpu() Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
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Ben Hutchings authored
dma_map_single() may fail if an IOMMU or swiotlb is in use, so we need to check for this. Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
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Ben Hutchings authored
Currently we try to clear EDRRR and EDTRR and immediately continue to free buffers. This is unsafe because: - In general, register writes are not serialised with DMA, so we still have to wait for DMA to complete somehow - The R8A7790 (R-Car H2) manual states that the TX running flag cannot be cleared by writing to EDTRR - The same manual states that clearing the RX running flag only stops RX DMA at the next packet boundary I applied this patch to the driver to detect DMA writes to freed buffers: > --- a/drivers/net/ethernet/renesas/sh_eth.c > +++ b/drivers/net/ethernet/renesas/sh_eth.c > @@ -1098,7 +1098,14 @@ static void sh_eth_ring_free(struct net_device *ndev) > /* Free Rx skb ringbuffer */ > if (mdp->rx_skbuff) { > for (i = 0; i < mdp->num_rx_ring; i++) > + memcpy(mdp->rx_skbuff[i]->data, > + "Hello, world", 12); > + msleep(100); > + for (i = 0; i < mdp->num_rx_ring; i++) { > + WARN_ON(memcmp(mdp->rx_skbuff[i]->data, > + "Hello, world", 12)); > dev_kfree_skb(mdp->rx_skbuff[i]); > + } > } > kfree(mdp->rx_skbuff); > mdp->rx_skbuff = NULL; then ran the loop: while ethtool -G eth0 rx 128 ; ethtool -G eth0 rx 64; do echo -n .; done and 'ping -f' toward the sh_eth port from another machine. The warning fired several times a minute. To fix these issues: - Deactivate all TX descriptors rather than writing to EDTRR - As there seems to be no way of telling when RX DMA is stopped, perform a soft reset to ensure that both DMA enginess are stopped - To reduce the possibility of the reset truncating a transmitted frame, disable egress and wait a reasonable time to reach a packet boundary before resetting - Update statistics before resetting (The 'reasonable time' does not allow for CS/CD in half-duplex mode, but half-duplex no longer seems reasonable!) Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
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