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2009-06-12lguest: remove invalid interrupt forcing logic.Rusty Russell
20887611523e749d99cc7d64ff6c97d27529fbae (lguest: notify on empty) introduced lguest support for the VIRTIO_F_NOTIFY_ON_EMPTY flag, but in fact it turned on interrupts all the time. Because we always process one buffer at a time, the inflight count is always 0 when call trigger_irq and so we always ignore VRING_AVAIL_F_NO_INTERRUPT from the Guest. It should be looking to see if there are more buffers in the Guest's queue: if it's empty, then we force an interrupt. This makes little difference, since we usually have an empty queue; but that's the subject of another patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: fix lguest wake on guest clock tick, or fd activityRusty Russell
The Launcher could be inside the Guest on another CPU; wake_up_process will do nothing because it is "running". kick_process will knock it back into our kernel in this case, otherwise we'll miss it until the next guest exit. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12sched: export kick_processRusty Russell
lguest needs kick_process: wake_up_process() does nothing if a process is running, which isn't sufficient (we need it in the kernel). And lguest support is usually modular. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu>
2009-06-12lguest: get more serious about wmb() in example Launcher codeRusty Russell
Since the Launcher process runs the Guest, it doesn't have to be very serious about its barriers: the Guest isn't running while we are (Guest is UP). Before we change to use threads to service devices, we need to fix this. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: clean up lguest_init_IRQRusty Russell
Copy from arch/x86/kernel/irqinit_32.c: we don't use the vectors beyond LGUEST_IRQS (if any), but we might as well set them all. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: cleanup passing of /dev/lguest fd around example launcher.Rusty Russell
We hand the /dev/lguest fd everywhere; it's far neater to just make it a global (it already is, in fact, hidden in the waker_fds struct). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: be paranoid about guest playing with device descriptors.Rusty Russell
We can't trust the values in the device descriptor table once the guest has booted, so keep local copies. They could set them to strange values then cause us to segv (they're 8 bit values, so they can't make our pointers go too wild). This becomes more important with the following patches which read them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: enhance id_matching for virtio driversChristian Borntraeger
This patch allows a virtio driver to use VIRTIO_DEV_ANY_ID for the device id. This will be used by a test module that can be bound to any virtio device. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: fix id_matching for virtio driversChristian Borntraeger
This bug never appeared, since all current virtio drivers use VIRTIO_DEV_ANY_ID for the vendor field. If a real vendor would be used, the check in virtio_id_match is wrong - it returns 0 if id->vendor == dev->id.vendor. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: handle short buffers in virtio_rng.Rusty Russell
If the device fills less than 4 bytes of our random buffer, we'll BUG_ON. It's nicer to handle the case where it partially fills the buffer (the protocol doesn't explicitly bad that). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio_blk: add missing __dev{init,exit} markingsMike Frysinger
The remove member of the virtio_driver structure uses __devexit_p(), so the remove function itself should be marked with __devexit. And where there be __devexit on the remove, so is there __devinit on the probe. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: indirect ring entries (VIRTIO_RING_F_INDIRECT_DESC)Mark McLoughlin
Add a new feature flag for indirect ring entries. These are ring entries which point to a table of buffer descriptors. The idea here is to increase the ring capacity by allowing a larger effective ring size whereby the ring size dictates the number of requests that may be outstanding, rather than the size of those requests. This should be most effective in the case of block I/O where we can potentially benefit by concurrently dispatching a large number of large requests. Even in the simple case of single segment block requests, this results in a threefold increase in ring capacity. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: teach virtio_has_feature() about transport featuresMark McLoughlin
Drivers don't add transport features to their table, so we shouldn't check these with virtio_check_driver_offered_feature(). We could perhaps add an ->offered_feature() virtio_config_op, but that perhaps that would be overkill for a consitency check like this. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: expose features in sysfsRusty Russell
Each device negotiates feature bits; expose these in sysfs to help diagnostics and debugging. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio_pci: optional MSI-X supportMichael S. Tsirkin
This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ whitespace, style)
2009-06-12virtio_pci: split up vp_interruptMichael S. Tsirkin
This reorganizes virtio-pci code in vp_interrupt slightly, so that it's easier to add per-vq MSI support on top. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: find_vqs/del_vqs virtio operationsMichael S. Tsirkin
This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations, and updates all drivers. This is needed for MSI support, because MSI needs to know the total number of vectors upfront. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
2009-06-12virtio: add names to virtqueue struct, mapping from devices to queues.Rusty Russell
Add a linked list of all virtqueues for a virtio device: this helps for debugging and is also needed for upcoming interface change. Also, add a "name" field for clearer debug messages. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: meet virtio spec by finalizing features before using deviceRusty Russell
Virtio devices are supposed to negotiate features before they start using the device, but the current code doesn't do this. This is because the driver's probe() function invariably has to add buffers to a virtqueue, or probe the disk (virtio_blk). This currently doesn't matter since no existing backend is strict about the feature negotiation. But it's possible to imagine a future feature which completely changes how a device operates: in this case, we'd need to acknowledge it before using the device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: fix obsolete documentation on probe functionRusty Russell
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12GFS2: Remove lock_kernel from gfs2_put_super()Steven Whitehouse
It is not required here. Signed-off-by: Steven Whitehouse <swhiteho@redhat,com> Cc: Christoph Hellwig <hch@infradead.org>
2009-06-12module: cleanup FIXME comments about trimming exception table entries.Rusty Russell
Everyone cut and paste this comment from my original one. We now do it generically, so cut the comments. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Amerigo Wang <amwang@redhat.com>
2009-06-12module: trim exception table on init free.Rusty Russell
It's theoretically possible that there are exception table entries which point into the (freed) init text of modules. These could cause future problems if other modules get loaded into that memory and cause an exception as we'd see the wrong fixup. The only case I know of is kvm-intel.ko (when CONFIG_CC_OPTIMIZE_FOR_SIZE=n). Amerigo fixed this long-standing FIXME in the x86 version, but this patch is more general. This implements trim_init_extable(); most archs are simple since they use the standard lib/extable.c sort code. Alpha and IA64 use relative addresses in their fixups, so thier trimming is a slight variation. Sparc32 is unique; it doesn't seem to define ARCH_HAS_SORT_EXTABLE, yet it defines its own sort_extable() which overrides the one in lib. It doesn't sort, so we have to mark deleted entries instead of actually trimming them. Inspired-by: Amerigo Wang <amwang@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: linux-alpha@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-ia64@vger.kernel.org
2009-06-12module: merge module_alloc() finallyAmerigo Wang
As Christoph Hellwig suggested, module_alloc() actually can be unified for i386 and x86_64 (of course, also UML). Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: 'Ingo Molnar' <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12uml module: fix uml build process due to this mergeAmerigo Wang
Due to the previous merge, uml needs to be fixed. Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12x86 module: merge the rest functions with macrosAmerigo Wang
Merge the rest functions together, with proper preprocessing directives. Finally remove module_{32|64}.c. Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12x86 module: merge the same functions in module_32.c and module_64.cAmerigo Wang
Merge the same functions both in module_32.c and module_64.c into module.c. This is the first step to merge both of them finally. Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12uvesafb: improve parameter handling.Rusty Russell
1) Now module_param(..., invbool, ...) requires a bool, and similarly module_param(..., bool, ...) allows it, change pmi_setpal to a bool. 2) #define param_get_scroll to NULL, since it can never be called (perm argument to module_param_named is 0). 3) Return -EINVAL from param_set_scroll if the value is bad, so it's reported. Note that I don't think the old fb_get_options() is required for new drivers: the parameters automatically work as uvesafb.XXX=... anyway. Acked-by: Michał Januszewski <spock@gentoo.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12module_param: allow 'bool' module_params to be bool, not just int.Rusty Russell
Impact: API cleanup For historical reasons, 'bool' parameters must be an int, not a bool. But there are around 600 users, so a conversion seems like useless churn. So we use __same_type() to distinguish, and handle both cases. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12module_param: add __same_type convenience wrapper for ↵Rusty Russell
__builtin_types_compatible_p Impact: new API __builtin_types_compatible_p() is a little awkward to use: it takes two types rather than types or variables, and it's just damn long. (typeof(type) == type, so this works on types as well as vars). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12module_param: split perm field into flags and permRusty Russell
Impact: cleanup Rather than hack KPARAM_KMALLOCED into the perm field, separate it out. Since the perm field was 32 bits and only needs 16, we don't add bloat. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12module_param: invbool should take a 'bool', not an 'int'Rusty Russell
It takes an 'int' for historical reasons, and there are only two users: simply switch it over to bool. The other user (uvesafb.c) will get a (harmless-on-x86) warning until the next patch is applied. Cc: Brad Douglas <brad@neruo.com> Cc: Michal Januszewski <spock@gentoo.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12cyber2000fb.c: use proper method for stopping unload if CONFIG_ARCH_SHARKRusty Russell
Russell explains the __module_get(): > cyber2000fb.c does it in its module initialization function > to prevent the module (when built for Shark) from being unloaded. It > does this because it's from the days of 2.2 kernels and no one bothered > writing the module unload support for Shark. Since 2.4, the correct answer has been to not define an unload fn. Cc: Russell King <rmk+lkml@arm.linux.org.uk> Cc: alex@shark-linux.de Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12x86: make zap_low_mapping could be used earlyYinghai Lu
Only one cpu is there, just call __flush_tlb for it. Fixes the following boot warning on x86: [ 0.000000] Memory: 885032k/915540k available (5993k kernel code, 29844k reserved, 3842k data, 428k init, 0k highmem) [ 0.000000] virtual kernel memory layout: [ 0.000000] fixmap : 0xffe17000 - 0xfffff000 (1952 kB) [ 0.000000] vmalloc : 0xf8615000 - 0xffe15000 ( 120 MB) [ 0.000000] lowmem : 0xc0000000 - 0xf7e15000 ( 894 MB) [ 0.000000] .init : 0xc19a5000 - 0xc1a10000 ( 428 kB) [ 0.000000] .data : 0xc15da4bb - 0xc199af6c (3842 kB) [ 0.000000] .text : 0xc1000000 - 0xc15da4bb (5993 kB) [ 0.000000] Checking if this processor honours the WP bit even in supervisor mode...Ok. [ 0.000000] ------------[ cut here ]------------ [ 0.000000] WARNING: at kernel/smp.c:369 smp_call_function_many+0x50/0x1b0() [ 0.000000] Hardware name: System Product Name [ 0.000000] Modules linked in: [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.30-tip #52504 [ 0.000000] Call Trace: [ 0.000000] [<c104aa16>] warn_slowpath_common+0x65/0x95 [ 0.000000] [<c104aa58>] warn_slowpath_null+0x12/0x15 [ 0.000000] [<c1073bbe>] smp_call_function_many+0x50/0x1b0 [ 0.000000] [<c1037615>] ? do_flush_tlb_all+0x0/0x41 [ 0.000000] [<c1037615>] ? do_flush_tlb_all+0x0/0x41 [ 0.000000] [<c1073d4f>] smp_call_function+0x31/0x58 [ 0.000000] [<c1037615>] ? do_flush_tlb_all+0x0/0x41 [ 0.000000] [<c104f635>] on_each_cpu+0x26/0x65 [ 0.000000] [<c10374b5>] flush_tlb_all+0x19/0x1b [ 0.000000] [<c1032ab3>] zap_low_mappings+0x4d/0x56 [ 0.000000] [<c15d64b5>] ? printk+0x14/0x17 [ 0.000000] [<c19b42a8>] mem_init+0x23d/0x245 [ 0.000000] [<c19a56a1>] start_kernel+0x17a/0x2d5 [ 0.000000] [<c19a5347>] ? unknown_bootoption+0x0/0x19a [ 0.000000] [<c19a5039>] __init_begin+0x39/0x41 [ 0.000000] ---[ end trace 4eaa2a86a8e2da22 ]--- Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-12irq: slab alloc for default irq_affinityYinghai Lu
Ingo had [ 0.000000] ------------[ cut here ]------------ [ 0.000000] WARNING: at mm/bootmem.c:537 alloc_arch_preferred_bootmem+0x2b/0x71() [ 0.000000] Hardware name: System Product Name [ 0.000000] Modules linked in: [ 0.000000] Pid: 0, comm: swapper Tainted: G W 2.6.30-tip-03087-g0bb2618-dirty #52506 [ 0.000000] Call Trace: [ 0.000000] [<81032588>] warn_slowpath_common+0x60/0x90 [ 0.000000] [<810325c5>] warn_slowpath_null+0xd/0x10 [ 0.000000] [<819d1bc0>] alloc_arch_preferred_bootmem+0x2b/0x71 [ 0.000000] [<819d1c31>] ___alloc_bootmem_nopanic+0x2b/0x9a [ 0.000000] [<81050a0a>] ? lock_release+0xac/0xb2 [ 0.000000] [<819d1d4c>] ___alloc_bootmem+0xe/0x2d [ 0.000000] [<819d1e9f>] __alloc_bootmem+0xa/0xc [ 0.000000] [<819d7c63>] alloc_bootmem_cpumask_var+0x21/0x26 [ 0.000000] [<819d0cc8>] early_irq_init+0x15/0x10d [ 0.000000] [<819bb75a>] start_kernel+0x167/0x326 [ 0.000000] [<819bb06b>] __init_begin+0x6b/0x70 [ 0.000000] ---[ end trace 4eaa2a86a8e2da23 ]--- [ 0.000000] NR_IRQS:2304 nr_irqs:424 [ 0.000000] CPU 0 irqstacks, hard=821e6000 soft=821e7000 we need to update init_irq_default_affinity Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-12memcg: fix page_cgroup fatal error in FLATMEMKAMEZAWA Hiroyuki
Now, SLAB is configured in very early stage and it can be used in init routine now. But replacing alloc_bootmem() in FLAT/DISCONTIGMEM's page_cgroup() initialization breaks the allocation, now. (Works well in SPARSEMEM case...it supports MEMORY_HOTPLUG and size of page_cgroup is in reasonable size (< 1 << MAX_ORDER.) This patch revive FLATMEM+memory cgroup by using alloc_bootmem. In future, We stop to support FLATMEM (if no users) or rewrite codes for flatmem completely.But this will adds more messy codes and overheads. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Tested-by: Li Zefan <lizf@cn.fujitsu.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-12GFS2: Add tracepointsSteven Whitehouse
This patch adds the ability to trace various aspects of the GFS2 filesystem. The trace points are divided into three groups, glocks, logging and bmap. These points have been chosen because they allow inspection of the major internal functions of GFS2 and they are also generic enough that they are unlikely to need any major changes as the filesystem evolves. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-06-12x86: Provide _sdata in the vmlinux.lds.S fileCatalin Marinas
_sdata is a common symbol defined by many architectures and made available to the kernel via asm-generic/sections.h. Kmemleak uses this symbol when scanning the data sections. [ Impact: add new global symbol ] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> LKML-Reference: <20090511122105.26556.96593.stgit@pc1117.cambridge.arm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-12block: fix kernel-doc in recent block/ changesRandy Dunlap
Fix kernel-doc warnings in recently changed block/ source code. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (87 commits) nilfs2: get rid of bd_mount_sem use from nilfs nilfs2: correct exclusion control in nilfs_remount function nilfs2: simplify remaining sget() use nilfs2: get rid of sget use for checking if current mount is present nilfs2: get rid of sget use for acquiring nilfs object nilfs2: remove meaningless EBUSY case from nilfs_get_sb function remove the call to ->write_super in __sync_filesystem nilfs2: call nilfs2_write_super from nilfs2_sync_fs jffs2: call jffs2_write_super from jffs2_sync_fs ufs: add ->sync_fs sysv: add ->sync_fs hfsplus: add ->sync_fs hfs: add ->sync_fs fat: add ->sync_fs ext2: add ->sync_fs exofs: add ->sync_fs bfs: add ->sync_fs affs: add ->sync_fs sanitize ->fsync() for affs repair bfs_write_inode(), switch bfs to simple_fsync() ...
2009-06-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: m68knommu: remove unecessary include of thread_info.h in entry.S m68knommu: enumerate INIT_THREAD fields properly headers_check fix: m68k, swab.h arch/m68knommu: Convert #ifdef DEBUG printk(KERN_DEBUG to pr_debug( m68knommu: remove obsolete reset code m68knommu: move CPU reset code for the 5272 ColdFire into its platform code m68knommu: move CPU reset code for the 528x ColdFire into its platform code m68knommu: move CPU reset code for the 527x ColdFire into its platform code m68knommu: move CPU reset code for the 523x ColdFire into its platform code m68knommu: move CPU reset code for the 520x ColdFire into its platform code m68knommu: add CPU reset code for the 532x ColdFire m68knommu: add CPU reset code for the 5249 ColdFire m68knommu: add CPU reset code for the 5206e ColdFire m68knommu: add CPU reset code for the 5206 ColdFire m68knommu: add CPU reset code for the 5407 ColdFire m68knommu: add CPU reset code for the 5307 ColdFire m68knommu: merge system reset for code ColdFire 523x family m68knommu: fix system reset for ColdFire 527x family
2009-06-12kvm: remove the duplicated cpumask_clearYinghai Lu
zalloc_cpumask_var already cleared it. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-12x86: use zalloc_cpumask_var in arch_early_irq_initYinghai Lu
So we make sure MAXSMP gets a cleared cpumask Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-12perfcounters: remove powerpc definitions of perf_counter_do_pendingStephen Rothwell
Commit 925d519ab82b6dd7aca9420d809ee83819c08db2 ("perf_counter: unify and fix delayed counter wakeup") added global definitions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Paul Mackerras <paulus@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-12nilfs2: get rid of bd_mount_sem use from nilfsRyusuke Konishi
This will remove every bd_mount_sem use in nilfs. The intended exclusion control was replaced by the previous patch ("nilfs2: correct exclusion control in nilfs_remount function") for nilfs_remount(), and this patch will replace remains with a new mutex that this inserts in nilfs object. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-12nilfs2: correct exclusion control in nilfs_remount functionRyusuke Konishi
nilfs_remount() changes mount state of a superblock instance. Even though nilfs accesses other superblock instances during mount or remount, the mount state was not properly protected in nilfs_remount(). Moreover, nilfs_remount() has a lock order reversal problem; nilfs_get_sb() holds: 1. bdev->bd_mount_sem 2. sb->s_umount (sget acquires) and nilfs_remount() holds: 1. sb->s_umount (locked by the caller in vfs) 2. bdev->bd_mount_sem To avoid these problems, this patch divides a semaphore protecting super block instances from nilfs->ns_sem, and applies it to the mount state protection in nilfs_remount(). With this change, bd_mount_sem use is removed from nilfs_remount() and the lock order reversal will be resolved. And the new rw-semaphore, nilfs->ns_super_sem will properly protect the mount state except the modification from nilfs_error function. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-12nilfs2: simplify remaining sget() useRyusuke Konishi
This simplifies the test function passed on the remaining sget() callsite in nilfs. Instead of checking mount type (i.e. ro-mount/rw-mount/snapshot mount) in the test function passed to sget(), this patch first looks up the nilfs_sb_info struct which the given mount type matches, and then acquires the super block instance holding the nilfs_sb_info. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-12nilfs2: get rid of sget use for checking if current mount is presentRyusuke Konishi
This stops using sget() for checking if an r/w-mount or an r/o-mount exists on the device. This elimination uses a back pointer to the current mount added to nilfs object. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-12nilfs2: get rid of sget use for acquiring nilfs objectRyusuke Konishi
This will change the way to obtain nilfs object in nilfs_get_sb() function. Previously, a preliminary sget() call was performed, and the nilfs object was acquired from a super block instance found by the sget() call. This patch, instead, instroduces a new dedicated function find_or_create_nilfs(); as the name implies, the function finds an existent nilfs object from a global list or creates a new one if no object is found on the device. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-12nilfs2: remove meaningless EBUSY case from nilfs_get_sb functionRyusuke Konishi
The following EBUSY case in nilfs_get_sb() is meaningless. Indeed, this error code is never returned to the caller. if (!s->s_root) { ... } else if (!(s->s_flags & MS_RDONLY)) { err = -EBUSY; } This simply removes the else case. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>