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2006-11-05[SPARC]: Fix robust futex syscalls and wire up migrate_pages.David S. Miller
When I added the entries for the robust futex syscall entries, I forgot to bump NR_SYSCALLS. The current situation is error-prone because NR_SYSCALLS lives in entry.S where the system call limit checks are enforced. Move the definition to asm/unistd.h in order to make this mistake much more difficult to make. And wire up sys_migrate_pages since the powerpc folks implemented the compat wrapper for us. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-11-03Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6Linus Torvalds
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6: PCI: Let PCI_MULTITHREAD_PROBE depend on BROKEN PCI: Revert "PCI: i386/x86_84: disable PCI resource decode on device disable"
2006-11-03[PATCH] uml: include tidyingJeff Dike
In order to get the __NR_* constants, we need sys/syscall.h. linux/unistd.h works as well since it includes syscall.h, however syscall.h is more parsimonious. We were inconsistent in this, and this patch adds syscall.h includes where necessary and removes linux/unistd.h includes where they are not needed. asm/unistd.h also includes the __NR_* constants, but these are not the glibc-sanctioned ones, so this also removes one such inclusion. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-03[PATCH] uml: fix I/O hangJeff Dike
Fix a UML hang in which everything would just stop until some I/O happened - a ping, someone whacking the keyboard - at which point everything would start up again as though nothing had happened. The cause was gcc reordering some code which absolutely needed to be executed in the order in the source. When unblock_signals switches signals from off to on, it needs to see if any interrupts had happened in the critical section. The interrupt handlers check signals_enabled - if it is zero, then the handler adds a bit to the "pending" bitmask and returns. unblock_signals checks this mask to see if any signals need to be delivered. The crucial part is this: signals_enabled = 1; save_pending = pending; if(save_pending == 0) return; pending = 0; In order to avoid an interrupt arriving between reading pending and setting it to zero, in which case, the record of the interrupt would be erased, signals are enabled. What happened was that gcc reordered this so that 'save_pending = pending' came before 'signals_enabled = 1', creating a one-instruction window within which an interrupt could arrive, set its bit in pending, and have it be immediately erased. When the I/O workload is purely disk-based, the loss of a block device interrupt stops the entire I/O system because the next block request will wait for the current one to finish. Thus the system hangs until something else causes some I/O to arrive, such as a network packet or console input. The fix to this particular problem is a memory barrier between enabling signals and reading the pending signal mask. An xchg would also probably work. Looking over this code for similar problems led me to do a few more things: - make signals_enabled and pending volatile so that they don't get cached in registers - add an mb() to the return paths of block_signals and unblock_signals so that the modification of signals_enabled doesn't get shuffled into the caller in the event that these are inlined in the future. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-03[PATCH] acpi_noirq section fixAndrew Morton
WARNING: vmlinux - Section mismatch: reference to .init.data:acpi_noirq from .text between 'pcibios_penalize_isa_irq' (at offset 0xc026ffa1) and 'pirq_serverworks_get' Acked-by: "Brown, Len" <len.brown@intel.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-02PCI: Revert "PCI: i386/x86_84: disable PCI resource decode on device disable"Greg Kroah-Hartman
This reverts commit 53e4d30dd666d7f83598957ee4a415eefb47c9a6. It was found that it caused unneeded problems (see http://bugzilla.kernel.org/show_bug.cgi?id=7082 for details of one such issue. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-11-02[MIPS] Do not use -msym32 option for modules.Atsushi Nemoto
On 64-bit kernel, modules are loaded into XKSEG for now. While XKSEG address is not a sign-extended 32-bit address, we can not use -msym32 option. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-02[MIPS] Ocelot G: Fix : "CURRENTLY_UNUSED" is not defined warning.Ralf Baechle
CC arch/mips/momentum/ocelot_g/gt-irq.o arch/mips/momentum/ocelot_g/gt-irq.c:30:5: warning: "CURRENTLY_UNUSED" is not defined arch/mips/momentum/ocelot_g/gt-irq.c:199:5: warning: "CURRENTLY_UNUSED" is not defined Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-02[MIPS] Fix warning about init_initrd() call if !CONFIG_BLK_DEV_INITRD.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-02[MIPS] IP27: Allow SMP ;-) Another changeset messed up by patch.Ralf Baechle
When lmo commit 4ef893e0515e8bf336dfbd200884f244869fbb43 was merged to kernel.org as e73ea273ef87a04ff59fc368fa33333dca275dde patch happily applied the IP27 segment to IP22. f63f36c18b11e166d0f362ac04dbcd7e6ea23f9e did fix the effects partially - and with a wrong log message. Now fixed for real (tm). Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-02[MIPS] Fix merge screwup by patch(1)Ralf Baechle
Patch happily applied an Ocelot G patch to Ocelot C when merging linux-mips.org changeset 91ee9a801e65d2981dfe327d2519c7fc6ab02e6b into kernel.org as 6ceb6d3ab2d402cea326320a4143db90a66fd216. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-02Revert "[MIPS] Make SPARSEMEM selectable on QEMU."Ralf Baechle
This reverts commit 31473747bd441719f9f6a07385684dce547533e0. Another amazing example of patch(1) messing up - lmo changeset 66e8560d11d02bcadc261498471831a6375ad046 was merged twice to kernel.org and ended up doing this rubbish job. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-01[PATCH] powerpc: Eliminate "exceeds stub group size" linker warningPaul Mackerras
It turns out that the linker warnings on 64-bit powerpc about "section blah exceeds stub group size" were being triggered by conditional branches in head_64.S branching to global symbols, whether in head_64.S or in other files. This eliminates the warnings by making some global symbols in head_64.S no longer global, and by rearranging some branches. Signed-off-by: Paul Mackerras <paulus@samba.org> [ Yee-haa. Maybe I'll notice newly introduced real warnings now - Linus ] Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-01Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linusLinus Torvalds
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: [MIPS] Fix warning in mips-boards generic PCI [MIPS] SMTC: Synchronize cp0 counters on bootup. [MIPS] SMTC: Fix crash if # of TC's > # of VPE's after pt_regs irq cleanup. [MIPS] 16K & 64K page size fixes
2006-11-01i386: write IO APIC irq routing entries in correct orderLinus Torvalds
Since the "mask" bit is in the low word, when we write a new entry, we need to write the high word first, before we potentially unmask it. The exception is when we actually want to mask the interrupt, in which case we want to write the low word first to make sure that the high word doesn't change while the interrupt routing is still active. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-01[MIPS] Fix warning in mips-boards generic PCIYoichi Yuasa
arch/mips/mips-boards/generic/pci.c: In function `mips_pcibios_init': arch/mips/mips-boards/generic/pci.c:227: warning: comparison of distinct pointer types lacks a cast arch/mips/mips-boards/generic/pci.c:228: warning: comparison of distinct pointer types lacks a cast Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-01[MIPS] SMTC: Synchronize cp0 counters on bootup.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-01[MIPS] SMTC: Fix crash if # of TC's > # of VPE's after pt_regs irq cleanup.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-01[MIPS] 16K & 64K page size fixesRalf Baechle
Derived from Peter Watkins <treestem@gmail.com>'s work. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-01i386: clean up io-apic accessesLinus Torvalds
This is preparation for fixing the ordering of the accesses that got broken by the commit cf4c6a2f27f5db810b69dcb1da7f194489e8ff88 when factoring out the "common" io apic routing entry accesses. Move the accessor function (that were only used by io_apic.c) out of a header file, and use proper memory-mapped accesses rather than making up our own "volatile" pointers. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-01[POWERPC] Make alignment exception always check exception tableBenjamin Herrenschmidt
The alignment exception used to only check the exception table for -EFAULT, not for other errors. That opens an oops window if we can coerce the kernel into getting an alignment exception for other reasons in what would normally be a user-protected accessor, which can be done via some of the futex ops. This fixes it by always checking the exception tables. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-11-01[POWERPC] Disallow kprobes on emulate_step and branch_takenGui,Jian
On powerpc, probing on emulate_step function will crash 2.6.18.1 when it is triggered. When kprobe is triggered, emulate_step() is on its kernel path and will cause recursive kprobe fault. And branch_taken() is called in emulate_step(). This disallows kprobes on both of them. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-11-01[POWERPC] Make high hugepage areas preempt safeHugh Dickins
Checking source for other get_paca()->field preemption dangers found that open_high_hpage_areas does a structure copy into its paca while preemption is enabled: unsafe however gcc accomplishes it. Just remove that copy: it's done safely afterwards by on_each_cpu, as in open_low_hpage_areas. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-11-01[POWERPC] qe_lib: qe_issue_cmd writes wrong value to CECDRTimur Tabi
Changed qe_issue_cmd() to write cmd_input to the CECDR unmodified. It was treating cmd_input as a virtual address and tried to convert it to a physical address. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-11-01[POWERPC] Use 4kB iommu pages even on 64kB-page systemsLinas Vepstas
The 10Gigabit ethernet device drivers appear to be able to chew up all 256MB of TCE mappings on pSeries systems, as evidenced by numerous error messages: iommu_alloc failed, tbl c0000000010d5c48 vaddr c0000000d875eff0 npages 1 Some experimentation indicates that this is essentially because one 1500 byte ethernet MTU gets mapped as a 64K DMA region when the large 64K pages are enabled. Thus, it doesn't take much to exhaust all of the available DMA mappings for a high-speed card. This patch changes the iommu allocator to work with its own unique, distinct page size. Although the patch is long, its actually quite simple: it just #defines a distinct IOMMU_PAGE_SIZE and then uses this in all the places that matter. As a side effect, it also dramatically improves network performance on platforms with H-calls on iommu translation inserts/removes (since we no longer call it 16 times for a 1500 bytes packet when the iommu HW is still 4k). In the future, we might want to make the IOMMU_PAGE_SIZE a variable in the iommu_table instance, thus allowing support for different HW page sizes in the iommu itself. Signed-off-by: Linas Vepstas <linas@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-11-01[POWERPC] Fix oprofile support for e500 in arch/powerpcAndy Fleming
Fixed a compile error in building the 85xx support with oprofile, and in the process cleaned up some issues with the fsl_booke performance monitor code. * Reorganized FSL Book-E performance monitoring code so that the 7450 wouldn't be built if the e500 was, and cleaned it up so it was more self-contained. * Added a cpu_setup function for FSL Book-E. The original cpu_setup function prototype had no arguments, assuming that the reg_setup function would copy the required information into variables which represented the registers. This was silly for e500, since it has 1 register per counter (rather than 3 for all counters), so the code has been restructured to have cpu_setup take the current counter config array as an argument, with op_powerpc_setup() invoking op_powerpc_cpu_setup() through on_each_cpu(), and op_powerpc_cpu_setup() invoking the model-specific cpu_setup function with an argument. The argument is ignored on all other platforms at present. * Fixed a confusing line where a trinary operator only had two arguments Signed-off-by: Andrew Fleming <afleming@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-11-01[POWERPC] Fix various offb issuesBenjamin Herrenschmidt
This patch fixes a few issues in offb: - A test was inverted causing the palette hack to never work (no device node was passed down to the init function) - Some cards seem to have their assigned-addresses property in a random order, thus we need to try using of_get_pci_address() first, which will fail if it's not a PCI device, and fallback to of_get_address() in that case. of_get_pci_address() properly parsees assigned-addresses to test the BAR number and thus will get it right whatever the order is. - Some cards (like GXT4500) provide a linebytes of 0xffffffff in the device-tree which does no good. This patch handles that by using the screen width when that happens. (Also fixes btext.c while at it). - Add detection of the GXT4500 in addition to the GXT2000 for the palette hacks (we use the same hack, palette is linear in register space at offset 0x6000). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-31Merge branch 'release' of ↵Linus Torvalds
master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6 * 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] Correct definition of handle_IPI [IA64] move SAL_CACHE_FLUSH check later in boot [IA64] MCA recovery: Montecito support [IA64] cpu-hotplug: Fixing confliction between CPU hot-add and IPI [IA64] don't double >> PAGE_SHIFT pointer for /dev/kmem access
2006-10-31[IA64] Correct definition of handle_IPIKeith Owens
The declaration of handle_IPI in arch/ia64/kernel/smp.c was changed but not the definition of this function. Remove struct pt_regs from handle_IPI(). Signed-off-by: Keith Owens <kaos@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-10-31[IA64] move SAL_CACHE_FLUSH check later in bootTroy Heber
The check to see if the firmware drops interrupts during a SAL_CACHE_FLUSH is done to early in the boot. SAL_CACHE_FLUSH expects to be able to make PAL calls in virtual mode, on some cell based machines a fault occurs causing a MCA. This patch moves the check after mmu_context_init so the TLB and VHPT are properly setup. Signed-off-by Troy Heber <troy.heber@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-10-31[IA64] MCA recovery: Montecito supportRuss Anderson
The information in MCA records is filled in slightly differently on Montecito than on Madison/McKinley. Usually, the cache check and bus check target identifiers have the same address. On Montecito the cache check and bus check target identifiers can be different if a corrected error (ie SBE or unconsumed poison data) was encountered and then an uncorrected error (ie DBE) was consumed. In that case, the cache check target identifier is the physical address of the DBE (that caused the MCA to surface) while the bus check target identifier is the physical address of the SBE. This patch correctly finds the target identifier that triggered the MCA. If there are multiple valid cache target identifiers in the same error record then use the one with the lowest cache level. Signed-off-by: Russ Anderson (rja@sgi.com) Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-10-31[IA64] cpu-hotplug: Fixing confliction between CPU hot-add and IPIKenji Kaneshige
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Acked-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-10-31[MIPS] Fixup migration to GENERIC_TIMEAtsushi Nemoto
Since we already moved to GENERIC_TIME, we should implement alternatives of old do_gettimeoffset routines to get sub-jiffies resolution from gettimeofday(). This patch includes: * MIPS clocksource support (based on works by Manish Lachwani). * remove unused gettimeoffset routines and related codes. * remove unised 64bit do_div64_32(). * simplify mips_hpt_init. (no argument needed, __init tag) * simplify c0_hpt_timer_init. (no need to write to c0_count) * remove some hpt_init routines. * mips_hpt_mask variable to specify bitmask of hpt value. * convert jmr3927_do_gettimeoffset to jmr3927_hpt_read. * convert ip27_do_gettimeoffset to ip27_hpt_read. * convert bcm1480_do_gettimeoffset to bcm1480_hpt_read. * simplify sb1250 hpt functions. (no need to subtract and shift) Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] VSMP: Synchronize cp0 counters on bootup.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] Flags must be unsigned long.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] VSMP: Fix initialization ordering bug.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] Fix warning of printk format in mips_srs_init()Yoichi Yuasa
arch/mips/kernel/traps.c:1115: warning: int format, long unsigned int arg (arg 2) Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] Yosemite: fix uninitialized variable in titan_i2c_xfer()Yoichi Yuasa
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] Sort out missuse of __init for prom_getcmdline()Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] Add missing file for support of backplane on TX4927 based boardManish Lachwani
Signed-off-by: Manish Lachwani <mlachwani@mvista.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31[MIPS] TX4927: Remove indent error message that somehow ended in the code.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-31Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6Linus Torvalds
* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6: sh: Titan defconfig update. sh: Fix IPR-IRQ's for IRQ-chip change breakage. sh: Update r7780rp_defconfig. video: Fix include in hp680_bl. sh: Wire up new syscalls.
2006-10-31Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6: [SPARC64]: Add some missing print_symbol() calls. [SPARC64]: Fix Tomatillo/Schizo IRQ handling.
2006-10-31[PATCH] uml: add _text definition to linker scriptsJeff Dike
kallsyms now refers to addresses as '_text + 0xADDRESS', rather than just '0xADDRESS', so we need to define _text. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31[PATCH] uml ubd driver: various little changesPaolo 'Blaisorblade' Giarrusso
Fix a small memory leak in ubd_config, and clearify the confusion which lead to it. Then, some little changes not affecting operations - * move init functions together, * add a comment about a potential problem in case of some evolution in the block layer, * mark all initcalls as static __init functions * mark an used once little function as inline * document that mconsole methods are all called in process context (was triggered when checking ubd mconsole methods). Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31[PATCH] uml ubd driver: do not store error codes as ->fdPaolo 'Blaisorblade' Giarrusso
To simplify error handling, make sure fd is saved into ubd_dev->fd only when we are sure it is an fd and not an error code. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31[PATCH] uml ubd driver: use bitfields where possiblePaolo 'Blaisorblade' Giarrusso
Use bitfields for boolean fields in ubd data structure. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31[PATCH] uml ubd driver: reformat ubd_configPaolo 'Blaisorblade' Giarrusso
Pure whitespace and style fixes split out from subsequent patch. Some changes (err -> ret) don't make sense now, only later, but I split them out anyway since they cluttered the patch. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31[PATCH] uml ubd driver: convert do_ubd to a boolean variablePaolo 'Blaisorblade' Giarrusso
do_ubd is actually just a boolean variable - the way it is used currently is a leftover from the old 2.4 block layer, but it is still used; its use is suspicious, but removing it would be too intrusive for now and needs more thinking. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31[PATCH] uml ubd driver: ubd_io_lock usage fixupPaolo 'Blaisorblade' Giarrusso
Add some comments about requirements for ubd_io_lock and expand its use. When an irq signals that the "controller" (i.e. another thread on the host, which does the actual requests and is the only one blocked on I/O on the host) has done some work, we call again the request function ourselves (do_ubd_request). We now do that with ubd_io_lock held - that's useful to protect against concurrent calls to elv_next_request and so on. XXX: Maybe we shouldn't call at all the request function. Input needed on this. Are we supposed to plug and unplug the queue? That code "indirectly" does that by setting a flag, called do_ubd, which makes the request function return (it's a residual of 2.4 block layer interface). Meanwhile, however, merge this patch, which improves things. Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>