From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vishal Verma Subject: [PATCH v6 0/5] dax: handling media errors (clear-on-zero only) Date: Tue, 10 May 2016 12:49:11 -0600 Message-ID: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Cc: Vishal Verma , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh To: linux-nvdimm@lists.01.org Return-path: Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org Until now, dax has been disabled if media errors were found on any device. This series attempts to address that. The first two patches from Dan re-enable dax even when media errors are present. The third patch from Matthew removes the zeroout path from dax entirely, making zeroout operations always go through the driver (The motivation is that if a backing device has media errors, and we create a sparse file on it, we don't want the initial zeroing to happen via dax, we want to give the block driver a chance to clear the errors). Patch 4 reduces our calls to clear_pmem from dax in the truncate/hole-punch cases. We check if the range being truncated is sector aligned/sized, and if so, send blkdev_issue_zeroout instead of clear_pmem so that errors can be handled better by the driver. Patch 5 fixes a redundant comment in DAX and is mostly unrelated to the rest of this series. This series also depends on/is based on Jan Kara's DAX Locking fixes series [1]. [1]: http://www.spinics.net/lists/linux-mm/msg105819.html v6: - Use IS_ALIGNED in dax_range_is_aligned instead of open coding an alignment check (Jan) - Collect all Reveiwed-by tags so far. v5: - Drop the patch that attempts to clear-errors-on-write till we reach consensus on how to handle that. - Don't pass blk_dax_ctl to direct_access, instead pass in all the required arguments individually (Christoph, Dan) v4: - Remove the dax->direct_IO fallbacks entirely. Instead, go through the usual direct_IO path when we're in O_DIRECT, and use dax_IO for other, non O_DIRECT IO. (Dan, Christoph) v3: - Wrapper-ize the direct_IO fallback again and make an exception for -EIOCBQUEUED (Jeff, Dan) - Reduce clear_pmem usage in DAX to the minimum Dan Williams (2): dax: fallback from pmd to pte on error dax: enable dax in the presence of known media errors (badblocks) Matthew Wilcox (1): dax: use sb_issue_zerout instead of calling dax_clear_sectors Vishal Verma (2): dax: for truncate/hole-punch, do zeroing through the driver if possible dax: fix a comment in dax_zero_page_range and dax_truncate_page Documentation/filesystems/dax.txt | 32 ++++++++++++++++ arch/powerpc/sysdev/axonram.c | 2 +- block/ioctl.c | 9 ----- drivers/block/brd.c | 2 +- drivers/nvdimm/pmem.c | 10 ++++- drivers/s390/block/dcssblk.c | 2 +- fs/block_dev.c | 2 +- fs/dax.c | 77 +++++++++++++-------------------------- fs/ext2/inode.c | 7 ++-- fs/xfs/xfs_bmap_util.c | 15 ++------ include/linux/blkdev.h | 2 +- include/linux/dax.h | 1 - 12 files changed, 79 insertions(+), 82 deletions(-) -- 2.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vishal Verma Subject: [PATCH v6 1/5] dax: fallback from pmd to pte on error Date: Tue, 10 May 2016 12:49:12 -0600 Message-ID: <1462906156-22303-2-git-send-email-vishal.l.verma@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Cc: Dan Williams , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh To: linux-nvdimm@lists.01.org Return-path: In-Reply-To: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Dan Williams In preparation for consulting a badblocks list in pmem_direct_access(), teach dax_pmd_fault() to fallback rather than fail immediately upon encountering an error. The thought being that reducing the span of the dax request may avoid the error region. Reviewed-by: Jeff Moyer Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Dan Williams --- fs/dax.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 5a34f08..52f0044 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1111,8 +1111,8 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, long length = dax_map_atomic(bdev, &dax); if (length < 0) { - result = VM_FAULT_SIGBUS; - goto out; + dax_pmd_dbg(&bh, address, "dax-error fallback"); + goto fallback; } if (length < PMD_SIZE) { dax_pmd_dbg(&bh, address, "dax-length too small"); -- 2.5.5 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vishal Verma Subject: [PATCH v6 3/5] dax: use sb_issue_zerout instead of calling dax_clear_sectors Date: Tue, 10 May 2016 12:49:14 -0600 Message-ID: <1462906156-22303-4-git-send-email-vishal.l.verma@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh , Vishal Verma To: linux-nvdimm@lists.01.org Return-path: In-Reply-To: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org From: Matthew Wilcox dax_clear_sectors() cannot handle poisoned blocks. These must be zeroed using the BIO interface instead. Convert ext2 and XFS to use only sb_issue_zerout(). Reviewed-by: Jeff Moyer Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Matthew Wilcox [vishal: Also remove the dax_clear_sectors function entirely] Signed-off-by: Vishal Verma --- fs/dax.c | 32 -------------------------------- fs/ext2/inode.c | 7 +++---- fs/xfs/xfs_bmap_util.c | 15 ++++----------- include/linux/dax.h | 1 - 4 files changed, 7 insertions(+), 48 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 52f0044..5948d9b 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -116,38 +116,6 @@ struct page *read_dax_sector(struct block_device *bdev, sector_t n) return page; } -/* - * dax_clear_sectors() is called from within transaction context from XFS, - * and hence this means the stack from this point must follow GFP_NOFS - * semantics for all operations. - */ -int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size) -{ - struct blk_dax_ctl dax = { - .sector = _sector, - .size = _size, - }; - - might_sleep(); - do { - long count, sz; - - count = dax_map_atomic(bdev, &dax); - if (count < 0) - return count; - sz = min_t(long, count, SZ_128K); - clear_pmem(dax.addr, sz); - dax.size -= sz; - dax.sector += sz / 512; - dax_unmap_atomic(bdev, &dax); - cond_resched(); - } while (dax.size); - - wmb_pmem(); - return 0; -} -EXPORT_SYMBOL_GPL(dax_clear_sectors); - static bool buffer_written(struct buffer_head *bh) { return buffer_mapped(bh) && !buffer_unwritten(bh); diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 1f07b75..35f2b0bf 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -737,10 +738,8 @@ static int ext2_get_blocks(struct inode *inode, * so that it's not found by another thread before it's * initialised */ - err = dax_clear_sectors(inode->i_sb->s_bdev, - le32_to_cpu(chain[depth-1].key) << - (inode->i_blkbits - 9), - 1 << inode->i_blkbits); + err = sb_issue_zeroout(inode->i_sb, + le32_to_cpu(chain[depth-1].key), 1, GFP_NOFS); if (err) { mutex_unlock(&ei->truncate_mutex); goto cleanup; diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 3b63098..930ac6a 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -72,18 +72,11 @@ xfs_zero_extent( struct xfs_mount *mp = ip->i_mount; xfs_daddr_t sector = xfs_fsb_to_db(ip, start_fsb); sector_t block = XFS_BB_TO_FSBT(mp, sector); - ssize_t size = XFS_FSB_TO_B(mp, count_fsb); - - if (IS_DAX(VFS_I(ip))) - return dax_clear_sectors(xfs_find_bdev_for_inode(VFS_I(ip)), - sector, size); - - /* - * let the block layer decide on the fastest method of - * implementing the zeroing. - */ - return sb_issue_zeroout(mp->m_super, block, count_fsb, GFP_NOFS); + return blkdev_issue_zeroout(xfs_find_bdev_for_inode(VFS_I(ip)), + block << (mp->m_super->s_blocksize_bits - 9), + count_fsb << (mp->m_super->s_blocksize_bits - 9), + GFP_NOFS, true); } /* diff --git a/include/linux/dax.h b/include/linux/dax.h index ef94fa7..426841a 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -11,7 +11,6 @@ ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t, get_block_t, dio_iodone_t, int flags); -int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size); int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t); int dax_truncate_page(struct inode *, loff_t from, get_block_t); int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); -- 2.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vishal Verma Subject: [PATCH v6 2/5] dax: enable dax in the presence of known media errors (badblocks) Date: Tue, 10 May 2016 12:49:13 -0600 Message-ID: <1462906156-22303-3-git-send-email-vishal.l.verma@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Cc: Dan Williams , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh , Vishal Verma To: linux-nvdimm@lists.01.org Return-path: In-Reply-To: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org From: Dan Williams 1/ If a mapping overlaps a bad sector fail the request. 2/ Do not opportunistically report more dax-capable capacity than is requested when errors present. Reviewed-by: Jeff Moyer Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams [vishal: fix a conflict with system RAM collision patches] [vishal: add a 'size' parameter to ->direct_access] Signed-off-by: Vishal Verma --- arch/powerpc/sysdev/axonram.c | 2 +- block/ioctl.c | 9 --------- drivers/block/brd.c | 2 +- drivers/nvdimm/pmem.c | 10 +++++++++- drivers/s390/block/dcssblk.c | 2 +- fs/block_dev.c | 2 +- include/linux/blkdev.h | 2 +- 7 files changed, 14 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c index 0d112b9..ff75d70 100644 --- a/arch/powerpc/sysdev/axonram.c +++ b/arch/powerpc/sysdev/axonram.c @@ -143,7 +143,7 @@ axon_ram_make_request(struct request_queue *queue, struct bio *bio) */ static long axon_ram_direct_access(struct block_device *device, sector_t sector, - void __pmem **kaddr, pfn_t *pfn) + void __pmem **kaddr, pfn_t *pfn, long size) { struct axon_ram_bank *bank = device->bd_disk->private_data; loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT; diff --git a/block/ioctl.c b/block/ioctl.c index 4ff1f92..bf80bfd 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -423,15 +423,6 @@ bool blkdev_dax_capable(struct block_device *bdev) || (bdev->bd_part->nr_sects % (PAGE_SIZE / 512))) return false; - /* - * If the device has known bad blocks, force all I/O through the - * driver / page cache. - * - * TODO: support finer grained dax error handling - */ - if (disk->bb && disk->bb->count) - return false; - return true; } #endif diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 51a071e..c04bd9b 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -381,7 +381,7 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector, #ifdef CONFIG_BLK_DEV_RAM_DAX static long brd_direct_access(struct block_device *bdev, sector_t sector, - void __pmem **kaddr, pfn_t *pfn) + void __pmem **kaddr, pfn_t *pfn, long size) { struct brd_device *brd = bdev->bd_disk->private_data; struct page *page; diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index f798899..c447579 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -182,14 +182,22 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector, } static long pmem_direct_access(struct block_device *bdev, sector_t sector, - void __pmem **kaddr, pfn_t *pfn) + void __pmem **kaddr, pfn_t *pfn, long size) { struct pmem_device *pmem = bdev->bd_disk->private_data; resource_size_t offset = sector * 512 + pmem->data_offset; + if (unlikely(is_bad_pmem(&pmem->bb, sector, size))) + return -EIO; *kaddr = pmem->virt_addr + offset; *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); + /* + * If badblocks are present, limit known good range to the + * requested range. + */ + if (unlikely(pmem->bb.count)) + return size; return pmem->size - pmem->pfn_pad - offset; } diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index b839086..c45d538 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -884,7 +884,7 @@ fail: static long dcssblk_direct_access (struct block_device *bdev, sector_t secnum, - void __pmem **kaddr, pfn_t *pfn) + void __pmem **kaddr, pfn_t *pfn, long size) { struct dcssblk_dev_info *dev_info; unsigned long offset, dev_sz; diff --git a/fs/block_dev.c b/fs/block_dev.c index b25bb23..02c68c4 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -488,7 +488,7 @@ long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax) sector += get_start_sect(bdev); if (sector % (PAGE_SIZE / 512)) return -EINVAL; - avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn); + avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn, size); if (!avail) return -ERANGE; if (avail > 0 && avail & ~PAGE_MASK) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 669e419..55ed530 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1657,7 +1657,7 @@ struct block_device_operations { int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); long (*direct_access)(struct block_device *, sector_t, void __pmem **, - pfn_t *); + pfn_t *, long); unsigned int (*check_events) (struct gendisk *disk, unsigned int clearing); /* ->media_changed() is DEPRECATED, use ->check_events() instead */ -- 2.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vishal Verma Subject: [PATCH v6 4/5] dax: for truncate/hole-punch, do zeroing through the driver if possible Date: Tue, 10 May 2016 12:49:15 -0600 Message-ID: <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Cc: Vishal Verma , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh To: linux-nvdimm@lists.01.org Return-path: In-Reply-To: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org In the truncate or hole-punch path in dax, we clear out sub-page ranges. If these sub-page ranges are sector aligned and sized, we can do the zeroing through the driver instead so that error-clearing is handled automatically. For sub-sector ranges, we still have to rely on clear_pmem and have the possibility of tripping over errors. Cc: Dan Williams Cc: Ross Zwisler Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Dave Chinner Cc: Jan Kara Reviewed-by: Christoph Hellwig Signed-off-by: Vishal Verma --- Documentation/filesystems/dax.txt | 32 ++++++++++++++++++++++++++++++++ fs/dax.c | 29 ++++++++++++++++++++++++----- 2 files changed, 56 insertions(+), 5 deletions(-) diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt index 7bde640..ce4587d 100644 --- a/Documentation/filesystems/dax.txt +++ b/Documentation/filesystems/dax.txt @@ -79,6 +79,38 @@ These filesystems may be used for inspiration: - ext4: the fourth extended filesystem, see Documentation/filesystems/ext4.txt +Handling Media Errors +--------------------- + +The libnvdimm subsystem stores a record of known media error locations for +each pmem block device (in gendisk->badblocks). If we fault at such location, +or one with a latent error not yet discovered, the application can expect +to receive a SIGBUS. Libnvdimm also allows clearing of these errors by simply +writing the affected sectors (through the pmem driver, and if the underlying +NVDIMM supports the clear_poison DSM defined by ACPI). + +Since DAX IO normally doesn't go through the driver/bio path, applications or +sysadmins have an option to restore the lost data from a prior backup/inbuilt +redundancy in the following ways: + +1. Delete the affected file, and restore from a backup (sysadmin route): + This will free the file system blocks that were being used by the file, + and the next time they're allocated, they will be zeroed first, which + happens through the driver, and will clear bad sectors. + +2. Truncate or hole-punch the part of the file that has a bad-block (at least + an entire aligned sector has to be hole-punched, but not necessarily an + entire filesystem block). + +These are the two basic paths that allow DAX filesystems to continue operating +in the presence of media errors. More robust error recovery mechanisms can be +built on top of this in the future, for example, involving redundancy/mirroring +provided at the block layer through DM, or additionally, at the filesystem +level. These would have to rely on the above two tenets, that error clearing +can happen either by sending an IO through the driver, or zeroing (also through +the driver). + + Shortcomings ------------ diff --git a/fs/dax.c b/fs/dax.c index 5948d9b..0167cde 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1196,6 +1196,20 @@ out: } EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); +static bool dax_range_is_aligned(struct block_device *bdev, + struct blk_dax_ctl *dax, unsigned int offset, + unsigned int length) +{ + unsigned short sector_size = bdev_logical_block_size(bdev); + + if (!IS_ALIGNED(((u64)dax->addr + offset), sector_size)) + return false; + if (!IS_ALIGNED(length, sector_size)) + return false; + + return true; +} + /** * dax_zero_page_range - zero a range within a page of a DAX file * @inode: The file being truncated @@ -1240,11 +1254,16 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, .size = PAGE_SIZE, }; - if (dax_map_atomic(bdev, &dax) < 0) - return PTR_ERR(dax.addr); - clear_pmem(dax.addr + offset, length); - wmb_pmem(); - dax_unmap_atomic(bdev, &dax); + if (dax_range_is_aligned(bdev, &dax, offset, length)) + return blkdev_issue_zeroout(bdev, dax.sector, + length >> 9, GFP_NOFS, true); + else { + if (dax_map_atomic(bdev, &dax) < 0) + return PTR_ERR(dax.addr); + clear_pmem(dax.addr + offset, length); + wmb_pmem(); + dax_unmap_atomic(bdev, &dax); + } } return 0; -- 2.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vishal Verma Subject: [PATCH v6 5/5] dax: fix a comment in dax_zero_page_range and dax_truncate_page Date: Tue, 10 May 2016 12:49:16 -0600 Message-ID: <1462906156-22303-6-git-send-email-vishal.l.verma@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Cc: Vishal Verma , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh , "Kirill A. Shutemov" To: linux-nvdimm@lists.01.org Return-path: In-Reply-To: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org The distinction between PAGE_SIZE and PAGE_CACHE_SIZE was removed in 09cbfea mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros The comments for the above functions described a distinction between those, that is now redundant, so remove those paragraphs Cc: Kirill A. Shutemov Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Vishal Verma --- fs/dax.c | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 0167cde..afa289c 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1221,12 +1221,6 @@ static bool dax_range_is_aligned(struct block_device *bdev, * page in a DAX file. This is intended for hole-punch operations. If * you are truncating a file, the helper function dax_truncate_page() may be * more convenient. - * - * We work in terms of PAGE_SIZE here for commonality with - * block_truncate_page(), but we could go down to PAGE_SIZE if the filesystem - * took care of disposing of the unnecessary blocks. Even if the filesystem - * block size is smaller than PAGE_SIZE, we have to zero the rest of the page - * since the file might be mmapped. */ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, get_block_t get_block) @@ -1278,12 +1272,6 @@ EXPORT_SYMBOL_GPL(dax_zero_page_range); * * Similar to block_truncate_page(), this function can be called by a * filesystem when it is truncating a DAX file to handle the partial page. - * - * We work in terms of PAGE_SIZE here for commonality with - * block_truncate_page(), but we could go down to PAGE_SIZE if the filesystem - * took care of disposing of the unnecessary blocks. Even if the filesystem - * block size is smaller than PAGE_SIZE, we have to zero the rest of the page - * since the file might be mmapped. */ int dax_truncate_page(struct inode *inode, loff_t from, get_block_t get_block) { -- 2.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH v6 4/5] dax: for truncate/hole-punch, do zeroing through the driver if possible Date: Tue, 10 May 2016 12:25:07 -0700 Message-ID: <20160510192507.GA29312@infradead.org> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh To: Vishal Verma Return-path: Content-Disposition: inline In-Reply-To: <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org Hi Vishal, can you also pick up the my patch to add a low-level __dax_zero_range that I cced you on? That way we can avoid a nasty merge conflict with my xfs/iomap changes. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Verma, Vishal L" Subject: Re: [PATCH v6 4/5] dax: for truncate/hole-punch, do zeroing through the driver if possible Date: Tue, 10 May 2016 19:49:01 +0000 Message-ID: <1462909729.29294.21.camel@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> <20160510192507.GA29312@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "xfs@oss.sgi.com" , "linux-nvdimm@ml01.01.org" , "jmoyer@redhat.com" , "linux-mm@kvack.org" , "Williams, Dan J" , "akpm@linux-foundation.org" , "linux-fsdevel@vger.kernel.org" , "ross.zwisler@linux.intel.com" , "linux-ext4@vger.kernel.org" , "boaz@plexistor.com" , "david@fromorbit.com" , "jack@suse.cz" To: "hch@infradead.org" , "axboe@fb.com" Return-path: In-Reply-To: <20160510192507.GA29312@infradead.org> Content-Language: en-US Content-ID: <21F7193DF9ABD64A97ED656576D4EB94@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org T24gVHVlLCAyMDE2LTA1LTEwIGF0IDEyOjI1IC0wNzAwLCBDaHJpc3RvcGggSGVsbHdpZyB3cm90 ZToNCj4gSGkgVmlzaGFsLA0KPiANCj4gY2FuIHlvdSBhbHNvIHBpY2sgdXAgdGhlIG15IHBhdGNo IHRvIGFkZCBhIGxvdy1sZXZlbCBfX2RheF96ZXJvX3JhbmdlDQo+IHRoYXQgSSBjY2VkIHlvdSBv bj/CoMKgVGhhdCB3YXkgd2UgY2FuIGF2b2lkIGEgbmFzdHkgbWVyZ2UgY29uZmxpY3Qgd2l0aA0K PiBteSB4ZnMvaW9tYXAgY2hhbmdlcy4NCg0KR29vZCBpZGVhIC0gSSdsbCBkbyB0aGF0IGZvciB0 aGUgbmV4dCBwb3N0aW5nLiBJJ2xsIHdhaXQgYSBkYXkgb3IgdHdvDQpmb3IgYW55IGFkZGl0aW9u YWwgcmV2aWV3cy9hY2tzLg0KDQpJJ20gbG9va2luZyB0byBnZXQgYWxsIHRoaXMgaW50byBhIGJy YW5jaCBpbiB0aGUgbnZkaW1tIHRyZWUgb25jZSBKYW4NCnNwbGl0cyB1cCBoaXMgZGF4LWxvY2tp bmcgc2VyaWVzLi4NCg0KTW9zdGx5IEkgZ3Vlc3MgSSdtIGxvb2tpbmcgZm9yIGEgeWF5IG9yIG5h eSBmb3IgdGhlIGJsb2NrIGxheWVyIGNoYW5nZXMNCihwYXRjaCAyKS4gSmVucz8= -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [PATCH v6 4/5] dax: for truncate/hole-punch, do zeroing through the driver if possible Date: Wed, 11 May 2016 10:15:32 +0200 Message-ID: <20160511081532.GB14744@quack2.suse.cz> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh To: Vishal Verma Return-path: Content-Disposition: inline In-Reply-To: <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On Tue 10-05-16 12:49:15, Vishal Verma wrote: > In the truncate or hole-punch path in dax, we clear out sub-page ranges. > If these sub-page ranges are sector aligned and sized, we can do the > zeroing through the driver instead so that error-clearing is handled > automatically. > > For sub-sector ranges, we still have to rely on clear_pmem and have the > possibility of tripping over errors. > > Cc: Dan Williams > Cc: Ross Zwisler > Cc: Jeff Moyer > Cc: Christoph Hellwig > Cc: Dave Chinner > Cc: Jan Kara > Reviewed-by: Christoph Hellwig > Signed-off-by: Vishal Verma ... > +static bool dax_range_is_aligned(struct block_device *bdev, > + struct blk_dax_ctl *dax, unsigned int offset, > + unsigned int length) > +{ > + unsigned short sector_size = bdev_logical_block_size(bdev); > + > + if (!IS_ALIGNED(((u64)dax->addr + offset), sector_size)) One more question: 'dax' is initialized in dax_zero_page_range() and dax->addr is going to be always NULL here. So either you forgot to call dax_map_atomic() to get the addr or the use of dax->addr is just bogus (which is what I currently believe since I see no way how the address could be unaligned with the sector_size)... Honza > + return false; > + if (!IS_ALIGNED(length, sector_size)) > + return false; > + > + return true; > +} > + > /** > * dax_zero_page_range - zero a range within a page of a DAX file > * @inode: The file being truncated > @@ -1240,11 +1254,16 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, > .size = PAGE_SIZE, > }; > > - if (dax_map_atomic(bdev, &dax) < 0) > - return PTR_ERR(dax.addr); > - clear_pmem(dax.addr + offset, length); > - wmb_pmem(); > - dax_unmap_atomic(bdev, &dax); > + if (dax_range_is_aligned(bdev, &dax, offset, length)) > + return blkdev_issue_zeroout(bdev, dax.sector, > + length >> 9, GFP_NOFS, true); > + else { > + if (dax_map_atomic(bdev, &dax) < 0) > + return PTR_ERR(dax.addr); > + clear_pmem(dax.addr + offset, length); > + wmb_pmem(); > + dax_unmap_atomic(bdev, &dax); > + } > } > > return 0; > -- > 2.5.5 > -- Jan Kara SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Verma, Vishal L" Subject: Re: [PATCH v6 4/5] dax: for truncate/hole-punch, do zeroing through the driver if possible Date: Wed, 11 May 2016 17:47:00 +0000 Message-ID: <1462988808.29294.26.camel@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> <20160511081532.GB14744@quack2.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "hch@infradead.org" , "xfs@oss.sgi.com" , "jmoyer@redhat.com" , "linux-mm@kvack.org" , "Williams, Dan J" , "axboe@fb.com" , "akpm@linux-foundation.org" , "linux-nvdimm@lists.01.org" , "linux-fsdevel@vger.kernel.org" , "ross.zwisler@linux.intel.com" , "linux-ext4@vger.kernel.org" , "boaz@plexistor.com" , "david@fromorbit.com" To: "jack@suse.cz" Return-path: In-Reply-To: <20160511081532.GB14744@quack2.suse.cz> Content-Language: en-US Content-ID: Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org T24gV2VkLCAyMDE2LTA1LTExIGF0IDEwOjE1ICswMjAwLCBKYW4gS2FyYSB3cm90ZToNCj4gT24g VHVlIDEwLTA1LTE2IDEyOjQ5OjE1LCBWaXNoYWwgVmVybWEgd3JvdGU6DQo+ID4gDQo+ID4gSW4g dGhlIHRydW5jYXRlIG9yIGhvbGUtcHVuY2ggcGF0aCBpbiBkYXgsIHdlIGNsZWFyIG91dCBzdWIt cGFnZQ0KPiA+IHJhbmdlcy4NCj4gPiBJZiB0aGVzZSBzdWItcGFnZSByYW5nZXMgYXJlIHNlY3Rv ciBhbGlnbmVkIGFuZCBzaXplZCwgd2UgY2FuIGRvIHRoZQ0KPiA+IHplcm9pbmcgdGhyb3VnaCB0 aGUgZHJpdmVyIGluc3RlYWQgc28gdGhhdCBlcnJvci1jbGVhcmluZyBpcyBoYW5kbGVkDQo+ID4g YXV0b21hdGljYWxseS4NCj4gPiANCj4gPiBGb3Igc3ViLXNlY3RvciByYW5nZXMsIHdlIHN0aWxs IGhhdmUgdG8gcmVseSBvbiBjbGVhcl9wbWVtIGFuZCBoYXZlDQo+ID4gdGhlDQo+ID4gcG9zc2li aWxpdHkgb2YgdHJpcHBpbmcgb3ZlciBlcnJvcnMuDQo+ID4gDQo+ID4gQ2M6IERhbiBXaWxsaWFt cyA8ZGFuLmoud2lsbGlhbXNAaW50ZWwuY29tPg0KPiA+IENjOiBSb3NzIFp3aXNsZXIgPHJvc3Mu endpc2xlckBsaW51eC5pbnRlbC5jb20+DQo+ID4gQ2M6IEplZmYgTW95ZXIgPGptb3llckByZWRo YXQuY29tPg0KPiA+IENjOiBDaHJpc3RvcGggSGVsbHdpZyA8aGNoQGluZnJhZGVhZC5vcmc+DQo+ ID4gQ2M6IERhdmUgQ2hpbm5lciA8ZGF2aWRAZnJvbW9yYml0LmNvbT4NCj4gPiBDYzogSmFuIEth cmEgPGphY2tAc3VzZS5jej4NCj4gPiBSZXZpZXdlZC1ieTogQ2hyaXN0b3BoIEhlbGx3aWcgPGhj aEBsc3QuZGU+DQo+ID4gU2lnbmVkLW9mZi1ieTogVmlzaGFsIFZlcm1hIDx2aXNoYWwubC52ZXJt YUBpbnRlbC5jb20+DQo+IC4uLg0KPiANCj4gPiANCj4gPiArc3RhdGljIGJvb2wgZGF4X3Jhbmdl X2lzX2FsaWduZWQoc3RydWN0IGJsb2NrX2RldmljZSAqYmRldiwNCj4gPiArCQkJCcKgc3RydWN0 IGJsa19kYXhfY3RsICpkYXgsIHVuc2lnbmVkDQo+ID4gaW50IG9mZnNldCwNCj4gPiArCQkJCcKg dW5zaWduZWQgaW50IGxlbmd0aCkNCj4gPiArew0KPiA+ICsJdW5zaWduZWQgc2hvcnQgc2VjdG9y X3NpemUgPSBiZGV2X2xvZ2ljYWxfYmxvY2tfc2l6ZShiZGV2KTsNCj4gPiArDQo+ID4gKwlpZiAo IUlTX0FMSUdORUQoKCh1NjQpZGF4LT5hZGRyICsgb2Zmc2V0KSwgc2VjdG9yX3NpemUpKQ0KPiBP bmUgbW9yZSBxdWVzdGlvbjogJ2RheCcgaXMgaW5pdGlhbGl6ZWQgaW4gZGF4X3plcm9fcGFnZV9y YW5nZSgpIGFuZA0KPiBkYXgtPmFkZHIgaXMgZ29pbmcgdG8gYmUgYWx3YXlzIE5VTEwgaGVyZS4g U28gZWl0aGVyIHlvdSBmb3Jnb3QgdG8NCj4gY2FsbA0KPiBkYXhfbWFwX2F0b21pYygpIHRvIGdl dCB0aGUgYWRkciBvciB0aGUgdXNlIG9mIGRheC0+YWRkciBpcyBqdXN0IGJvZ3VzDQo+ICh3aGlj aCBpcyB3aGF0IEkgY3VycmVudGx5IGJlbGlldmUgc2luY2UgSSBzZWUgbm8gd2F5IGhvdyB0aGUg YWRkcmVzcw0KPiBjb3VsZA0KPiBiZSB1bmFsaWduZWQgd2l0aCB0aGUgc2VjdG9yX3NpemUpLi4u DQo+IA0KDQpHb29kIGNhdGNoLCBhbmQgeW91J3JlIHJpZ2h0LiBJIGRvbid0IHRoaW5rIEkgYWN0 dWFsbHkgZXZlbiB3YW50IHRvIHVzZQ0KZGF4LT5hZGRyIGZvciB0aGUgYWxpZ25tZW50IGNoZWNr IGhlcmUgLSBJIHdhbnQgdG8gY2hlY2sgaWYgd2UncmUNCmFsaWduZWQgdG8gdGhlIGJsb2NrIGRl dmljZSBzZWN0b3IuIEknbSB0aGlua2luZyBzb21ldGhpbmcgbGlrZToNCg0KCWlmICghSVNfQUxJ R05FRChvZmZzZXQsIHNlY3Rvcl9zaXplKSkNCg0KVGVjaG5pY2FsbHkgd2Ugd2FudCB0byBjaGVj ayBpZiBzZWN0b3IgKiBzZWN0b3Jfc2l6ZSArIG9mZnNldCBpcw0KYWxpZ25lZCwgYnV0IHRoZSBm aXJzdCBwYXJ0IG9mIHRoYXQgaXMgYWxyZWFkeSBhIHNlY3RvciA6KQ== From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Verma, Vishal L" Subject: Re: [PATCH v6 4/5] dax: for truncate/hole-punch, do zeroing through the driver if possible Date: Wed, 11 May 2016 18:39:59 +0000 Message-ID: <1462991986.29294.29.camel@intel.com> References: <1462906156-22303-1-git-send-email-vishal.l.verma@intel.com> <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "hch@infradead.org" , "xfs@oss.sgi.com" , "jmoyer@redhat.com" , "linux-mm@kvack.org" , "Williams, Dan J" , "axboe@fb.com" , "akpm@linux-foundation.org" , "linux-fsdevel@vger.kernel.org" , "ross.zwisler@linux.intel.com" , "linux-ext4@vger.kernel.org" , "boaz@plexistor.com" , "david@fromorbit.com" , "jack@suse.cz" To: "linux-nvdimm@lists.01.org" Return-path: In-Reply-To: <1462906156-22303-5-git-send-email-vishal.l.verma@intel.com> Content-Language: en-US Content-ID: <5E1FB0B45FA4AB4A819E9443201F1C82@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org T24gVHVlLCAyMDE2LTA1LTEwIGF0IDEyOjQ5IC0wNjAwLCBWaXNoYWwgVmVybWEgd3JvdGU6DQo+ wqANCi4uLg0KDQo+IEBAIC0xMjQwLDExICsxMjU0LDE2IEBAIGludCBkYXhfemVyb19wYWdlX3Jh bmdlKHN0cnVjdCBpbm9kZSAqaW5vZGUsDQo+IGxvZmZfdCBmcm9tLCB1bnNpZ25lZCBsZW5ndGgs DQo+IMKgCQkJLnNpemUgPSBQQUdFX1NJWkUsDQo+IMKgCQl9Ow0KPiDCoA0KPiAtCQlpZiAoZGF4 X21hcF9hdG9taWMoYmRldiwgJmRheCkgPCAwKQ0KPiAtCQkJcmV0dXJuIFBUUl9FUlIoZGF4LmFk ZHIpOw0KPiAtCQljbGVhcl9wbWVtKGRheC5hZGRyICsgb2Zmc2V0LCBsZW5ndGgpOw0KPiAtCQl3 bWJfcG1lbSgpOw0KPiAtCQlkYXhfdW5tYXBfYXRvbWljKGJkZXYsICZkYXgpOw0KPiArCQlpZiAo ZGF4X3JhbmdlX2lzX2FsaWduZWQoYmRldiwgJmRheCwgb2Zmc2V0LCBsZW5ndGgpKQ0KPiArCQkJ cmV0dXJuIGJsa2Rldl9pc3N1ZV96ZXJvb3V0KGJkZXYsIGRheC5zZWN0b3IsDQo+ICsJCQkJCWxl bmd0aCA+PiA5LCBHRlBfTk9GUywgdHJ1ZSk7DQoNCkZvdW5kIGFub3RoZXIgYnVnIGhlcmUgd2hp bGUgdGVzdGluZy4gVGhlIHplcm9vdXQgbmVlZHMgdG8gYmUgZG9uZSBmb3INCnNlY3RvciArIChv ZmZzZXQgPj4gOSkuIFRoZSBhYm92ZSBqdXN0IHplcm9lZCBvdXQgdGhlIGZpcnN0IHNlY3RvciBv Zg0KdGhlIHBhZ2UgaXJyZXNwZWN0aXZlIG9mIG9mZnNldCwgd2hpY2ggaXMgd3Jvbmcu -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org