From 1a112d10f03e83fb3a2fdc4c9165865dec8a3ca6 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 23 Jul 2014 09:05:27 -0400 Subject: libata: introduce ata_host->n_tags to avoid oops on SAS controllers 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32") directly used ata_port->scsi_host->can_queue from ata_qc_new() to determine the number of tags supported by the host; unfortunately, SAS controllers doing SATA don't initialize ->scsi_host leading to the following oops. BUG: unable to handle kernel NULL pointer dereference at 0000000000000058 IP: [] ata_qc_new_init+0x188/0x1b0 PGD 0 Oops: 0002 [#1] SMP Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000 RIP: 0010:[] [] ata_qc_new_init+0x188/0x1b0 RSP: 0018:ffff88061a003ae8 EFLAGS: 00010012 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000 FS: 00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0 Stack: ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200 ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68 ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80 Call Trace: [] ata_sas_queuecmd+0xa1/0x430 [] sas_queuecommand+0x191/0x220 [libsas] [] scsi_dispatch_cmd+0x10e/0x300 [] scsi_request_fn+0x2f5/0x550 [] __blk_run_queue+0x33/0x40 [] queue_unplugged+0x2a/0x90 [] blk_flush_plug_list+0x1b4/0x210 [] blk_finish_plug+0x14/0x50 [] __do_page_cache_readahead+0x198/0x1f0 [] force_page_cache_readahead+0x31/0x50 [] page_cache_sync_readahead+0x3e/0x50 [] generic_file_read_iter+0x496/0x5a0 [] blkdev_read_iter+0x37/0x40 [] new_sync_read+0x7e/0xb0 [] vfs_read+0x94/0x170 [] SyS_read+0x46/0xb0 [] ? SyS_lseek+0x91/0xb0 [] system_call_fastpath+0x16/0x1b Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 <89> 14 25 58 00 00 00 Fix it by introducing ata_host->n_tags which is initialized to ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to scsi_host_template->can_queue in ata_host_register() for !SAS ones. As SAS hosts are never registered, this will give them the same ATA_MAX_QUEUE - 1 as before. Note that we can't use scsi_host->can_queue directly for SAS hosts anyway as they can go higher than the libata maximum. Signed-off-by: Tejun Heo Reported-by: Mike Qiu Reported-by: Jesse Brandeburg Reported-by: Peter Hurley Reported-by: Peter Zijlstra Tested-by: Alexey Kardashevskiy Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32") Cc: Kevin Hao Cc: Dan Williams Cc: stable@vger.kernel.org --- include/linux/libata.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/libata.h b/include/linux/libata.h index 5ab4e3a76721..92abb497ab14 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -593,6 +593,7 @@ struct ata_host { struct device *dev; void __iomem * const *iomap; unsigned int n_ports; + unsigned int n_tags; /* nr of NCQ tags */ void *private_data; struct ata_port_operations *ops; unsigned long flags; -- cgit v1.2.3 From a0f7a756c2f7543585657cdeeefdfcc11b567293 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Wed, 23 Jul 2014 14:00:01 -0700 Subject: mm/rmap.c: fix pgoff calculation to handle hugepage correctly I triggered VM_BUG_ON() in vma_address() when I tried to migrate an anonymous hugepage with mbind() in the kernel v3.16-rc3. This is because pgoff's calculation in rmap_walk_anon() fails to consider compound_order() only to have an incorrect value. This patch introduces page_to_pgoff(), which gets the page's offset in PAGE_CACHE_SIZE. Kirill pointed out that page cache tree should natively handle hugepages, and in order to make hugetlbfs fit it, page->index of hugetlbfs page should be in PAGE_CACHE_SIZE. This is beyond this patch, but page_to_pgoff() contains the point to be fixed in a single function. Signed-off-by: Naoya Horiguchi Acked-by: Kirill A. Shutemov Cc: Joonsoo Kim Cc: Hugh Dickins Cc: Rik van Riel Cc: Hillf Danton Cc: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/pagemap.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 0a97b583ee8d..e1474ae18c88 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -398,6 +398,18 @@ static inline struct page *read_mapping_page(struct address_space *mapping, return read_cache_page(mapping, index, filler, data); } +/* + * Get the offset in PAGE_SIZE. + * (TODO: hugepage should have ->index in PAGE_SIZE) + */ +static inline pgoff_t page_to_pgoff(struct page *page) +{ + if (unlikely(PageHeadHuge(page))) + return page->index << compound_order(page); + else + return page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); +} + /* * Return byte-offset into filesystem object for page. */ -- cgit v1.2.3