diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt index 7bde64014a89..ce4587d257d2 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/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c index 0d112b94d91d..ff75d70f7285 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 698c7933d582..ed2397f8de9d 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -4,7 +4,6 @@ #include #include #include -#include #include #include #include diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 51a071e32221..c04bd9bc39fd 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 042baec56931..608fc4464574 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -164,14 +164,22 @@ 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_queue->queuedata; 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 b83908670a9a..bed53c46dd90 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -31,7 +31,7 @@ static void dcssblk_release(struct gendisk *disk, fmode_t mode); static blk_qc_t dcssblk_make_request(struct request_queue *q, struct bio *bio); 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); static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; @@ -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 1089dbf25925..71ccab1d22c6 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -51,6 +51,18 @@ struct block_device *I_BDEV(struct inode *inode) } EXPORT_SYMBOL(I_BDEV); +void __vfs_msg(struct super_block *sb, const char *prefix, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + printk_ratelimited("%sVFS (%s): %pV\n", prefix, sb->s_id, &vaf); + va_end(args); +} + static void bdev_write_inode(struct block_device *bdev) { struct inode *inode = bdev->bd_inode; @@ -489,7 +501,7 @@ 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) @@ -498,6 +510,75 @@ long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax) } EXPORT_SYMBOL_GPL(bdev_direct_access); +/** + * bdev_dax_supported() - Check if the device supports dax for filesystem + * @sb: The superblock of the device + * @blocksize: The block size of the device + * + * This is a library function for filesystems to check if the block device + * can be mounted with dax option. + * + * Return: negative errno if unsupported, 0 if supported. + */ +int bdev_dax_supported(struct super_block *sb, int blocksize) +{ + struct blk_dax_ctl dax = { + .sector = 0, + .size = PAGE_SIZE, + }; + int err; + + if (blocksize != PAGE_SIZE) { + vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax"); + return -EINVAL; + } + + err = bdev_direct_access(sb->s_bdev, &dax); + if (err < 0) { + switch (err) { + case -EOPNOTSUPP: + vfs_msg(sb, KERN_ERR, + "error: device does not support dax"); + break; + case -EINVAL: + vfs_msg(sb, KERN_ERR, + "error: unaligned partition for dax"); + break; + default: + vfs_msg(sb, KERN_ERR, + "error: dax access failed (%d)", err); + } + return err; + } + + return 0; +} +EXPORT_SYMBOL_GPL(bdev_dax_supported); + +/** + * bdev_dax_capable() - Return if the raw device is capable for dax + * @bdev: The device for raw block device access + */ +bool bdev_dax_capable(struct block_device *bdev) +{ + struct blk_dax_ctl dax = { + .size = PAGE_SIZE, + }; + + if (!IS_ENABLED(CONFIG_FS_DAX)) + return false; + + dax.sector = 0; + if (bdev_direct_access(bdev, &dax) < 0) + return false; + + dax.sector = bdev->bd_part->nr_sects - (PAGE_SIZE / 512); + if (bdev_direct_access(bdev, &dax) < 0) + return false; + + return true; +} + /* * pseudo-fs */ @@ -1160,33 +1241,6 @@ void bd_set_size(struct block_device *bdev, loff_t size) } EXPORT_SYMBOL(bd_set_size); -static bool blkdev_dax_capable(struct block_device *bdev) -{ - struct gendisk *disk = bdev->bd_disk; - - if (!disk->fops->direct_access || !IS_ENABLED(CONFIG_FS_DAX)) - return false; - - /* - * If the partition is not aligned on a page boundary, we can't - * do dax I/O to it. - */ - if ((bdev->bd_part->start_sect % (PAGE_SIZE / 512)) - || (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; -} - static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); /* @@ -1266,7 +1320,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) if (!ret) { bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); - if (!blkdev_dax_capable(bdev)) + if (!bdev_dax_capable(bdev)) bdev->bd_inode->i_flags &= ~S_DAX; } @@ -1303,7 +1357,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) goto out_clear; } bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); - if (!blkdev_dax_capable(bdev)) + if (!bdev_dax_capable(bdev)) bdev->bd_inode->i_flags &= ~S_DAX; } } else { diff --git a/fs/dax.c b/fs/dax.c index 7d9df93b3a14..5a282260d27e 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -87,50 +87,6 @@ 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); - -/* the clear_pmem() calls are ordered by a wmb_pmem() in the caller */ -static void dax_new_buf(void __pmem *addr, unsigned size, unsigned first, - loff_t pos, loff_t end) -{ - loff_t final = end - pos + first; /* The final byte of the buffer */ - - if (first > 0) - clear_pmem(addr, first); - if (final < size) - clear_pmem(addr + final, size - final); -} - static bool buffer_written(struct buffer_head *bh) { return buffer_mapped(bh) && !buffer_unwritten(bh); @@ -169,6 +125,9 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, struct blk_dax_ctl dax = { .addr = (void __pmem *) ERR_PTR(-EIO), }; + unsigned blkbits = inode->i_blkbits; + sector_t file_blks = (i_size_read(inode) + (1 << blkbits) - 1) + >> blkbits; if (rw == READ) end = min(end, i_size_read(inode)); @@ -176,7 +135,6 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, while (pos < end) { size_t len; if (pos == max) { - unsigned blkbits = inode->i_blkbits; long page = pos >> PAGE_SHIFT; sector_t block = page << (PAGE_SHIFT - blkbits); unsigned first = pos - (block << blkbits); @@ -192,6 +150,13 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, bh->b_size = 1 << blkbits; bh_max = pos - first + bh->b_size; bdev = bh->b_bdev; + /* + * We allow uninitialized buffers for writes + * beyond EOF as those cannot race with faults + */ + WARN_ON_ONCE( + (buffer_new(bh) && block < file_blks) || + (rw == WRITE && buffer_unwritten(bh))); } else { unsigned done = bh->b_size - (bh_max - (pos - first)); @@ -211,11 +176,6 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, rc = map_len; break; } - if (buffer_unwritten(bh) || buffer_new(bh)) { - dax_new_buf(dax.addr, map_len, first, - pos, end); - need_wmb = true; - } dax.addr += first; size = map_len - first; } @@ -276,15 +236,8 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, memset(&bh, 0, sizeof(bh)); bh.b_bdev = inode->i_sb->s_bdev; - if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ) { - struct address_space *mapping = inode->i_mapping; + if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ) inode_lock(inode); - retval = filemap_write_and_wait_range(mapping, pos, end - 1); - if (retval) { - inode_unlock(inode); - goto out; - } - } /* Protects against truncate */ if (!(flags & DIO_SKIP_DIO_COUNT)) @@ -305,7 +258,6 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, if (!(flags & DIO_SKIP_DIO_COUNT)) inode_dio_end(inode); - out: return retval; } EXPORT_SYMBOL_GPL(dax_do_io); @@ -321,20 +273,11 @@ EXPORT_SYMBOL_GPL(dax_do_io); static int dax_load_hole(struct address_space *mapping, struct page *page, struct vm_fault *vmf) { - unsigned long size; - struct inode *inode = mapping->host; if (!page) page = find_or_create_page(mapping, vmf->pgoff, GFP_KERNEL | __GFP_ZERO); if (!page) return VM_FAULT_OOM; - /* Recheck i_size under page lock to avoid truncate race */ - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; - if (vmf->pgoff >= size) { - unlock_page(page); - put_page(page); - return VM_FAULT_SIGBUS; - } vmf->page = page; return VM_FAULT_LOCKED; @@ -565,33 +508,14 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh, .sector = to_sector(bh, inode), .size = bh->b_size, }; - pgoff_t size; int error; i_mmap_lock_read(mapping); - /* - * Check truncate didn't happen while we were allocating a block. - * If it did, this block may or may not be still allocated to the - * file. We can't tell the filesystem to free it because we can't - * take i_mutex here. In the worst case, the file still has blocks - * allocated past the end of the file. - */ - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; - if (unlikely(vmf->pgoff >= size)) { - error = -EIO; - goto out; - } - if (dax_map_atomic(bdev, &dax) < 0) { error = PTR_ERR(dax.addr); goto out; } - - if (buffer_unwritten(bh) || buffer_new(bh)) { - clear_pmem(dax.addr, PAGE_SIZE); - wmb_pmem(); - } dax_unmap_atomic(bdev, &dax); error = dax_radix_entry(mapping, vmf->pgoff, dax.sector, false, @@ -612,19 +536,13 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh, * @vma: The virtual memory area where the fault occurred * @vmf: The description of the fault * @get_block: The filesystem method used to translate file offsets to blocks - * @complete_unwritten: The filesystem method used to convert unwritten blocks - * to written so the data written to them is exposed. This is required for - * required by write faults for filesystems that will return unwritten - * extent mappings from @get_block, but it is optional for reads as - * dax_insert_mapping() will always zero unwritten blocks. If the fs does - * not support unwritten extents, the it should pass NULL. * * When a page fault occurs, filesystems may call this helper in their * fault handler for DAX files. __dax_fault() assumes the caller has done all * the necessary locking for the page fault to proceed successfully. */ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, - get_block_t get_block, dax_iodone_t complete_unwritten) + get_block_t get_block) { struct file *file = vma->vm_file; struct address_space *mapping = file->f_mapping; @@ -659,15 +577,6 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, put_page(page); goto repeat; } - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; - if (unlikely(vmf->pgoff >= size)) { - /* - * We have a struct page covering a hole in the file - * from a read fault and we've raced with a truncate - */ - error = -EIO; - goto unlock_page; - } } error = get_block(inode, block, &bh, 0); @@ -700,17 +609,8 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, if (error) goto unlock_page; vmf->page = page; - if (!page) { + if (!page) i_mmap_lock_read(mapping); - /* Check we didn't race with truncate */ - size = (i_size_read(inode) + PAGE_SIZE - 1) >> - PAGE_SHIFT; - if (vmf->pgoff >= size) { - i_mmap_unlock_read(mapping); - error = -EIO; - goto out; - } - } return VM_FAULT_LOCKED; } @@ -727,23 +627,9 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, page = NULL; } - /* - * If we successfully insert the new mapping over an unwritten extent, - * we need to ensure we convert the unwritten extent. If there is an - * error inserting the mapping, the filesystem needs to leave it as - * unwritten to prevent exposure of the stale underlying data to - * userspace, but we still need to call the completion function so - * the private resources on the mapping buffer can be released. We - * indicate what the callback should do via the uptodate variable, same - * as for normal BH based IO completions. - */ + /* Filesystem should not return unwritten buffers to us! */ + WARN_ON_ONCE(buffer_unwritten(&bh) || buffer_new(&bh)); error = dax_insert_mapping(inode, &bh, vma, vmf); - if (buffer_unwritten(&bh)) { - if (complete_unwritten) - complete_unwritten(&bh, !error); - else - WARN_ON_ONCE(!(vmf->flags & FAULT_FLAG_WRITE)); - } out: if (error == -ENOMEM) @@ -772,7 +658,7 @@ EXPORT_SYMBOL(__dax_fault); * fault handler for DAX files. */ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, - get_block_t get_block, dax_iodone_t complete_unwritten) + get_block_t get_block) { int result; struct super_block *sb = file_inode(vma->vm_file)->i_sb; @@ -781,7 +667,7 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, sb_start_pagefault(sb); file_update_time(vma->vm_file); } - result = __dax_fault(vma, vmf, get_block, complete_unwritten); + result = __dax_fault(vma, vmf, get_block); if (vmf->flags & FAULT_FLAG_WRITE) sb_end_pagefault(sb); @@ -815,8 +701,7 @@ static void __dax_dbg(struct buffer_head *bh, unsigned long address, #define dax_pmd_dbg(bh, address, reason) __dax_dbg(bh, address, reason, "dax_pmd") int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, - pmd_t *pmd, unsigned int flags, get_block_t get_block, - dax_iodone_t complete_unwritten) + pmd_t *pmd, unsigned int flags, get_block_t get_block) { struct file *file = vma->vm_file; struct address_space *mapping = file->f_mapping; @@ -875,6 +760,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, if (get_block(inode, block, &bh, 1) != 0) return VM_FAULT_SIGBUS; alloc = true; + WARN_ON_ONCE(buffer_unwritten(&bh) || buffer_new(&bh)); } bdev = bh.b_bdev; @@ -902,23 +788,6 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, i_mmap_lock_read(mapping); - /* - * If a truncate happened while we were allocating blocks, we may - * leave blocks allocated to the file that are beyond EOF. We can't - * take i_mutex here, so just leave them hanging; they'll be freed - * when the file is deleted. - */ - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; - if (pgoff >= size) { - result = VM_FAULT_SIGBUS; - goto out; - } - if ((pgoff | PG_PMD_COLOUR) >= size) { - dax_pmd_dbg(&bh, address, - "offset + huge page size > file size"); - goto fallback; - } - if (!write && !buffer_mapped(&bh) && buffer_uptodate(&bh)) { spinlock_t *ptl; pmd_t entry; @@ -954,8 +823,8 @@ 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"); @@ -973,14 +842,6 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, dax_pmd_dbg(&bh, address, "pfn not in memmap"); goto fallback; } - - if (buffer_unwritten(&bh) || buffer_new(&bh)) { - clear_pmem(dax.addr, PMD_SIZE); - wmb_pmem(); - count_vm_event(PGMAJFAULT); - mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); - result |= VM_FAULT_MAJOR; - } dax_unmap_atomic(bdev, &dax); /* @@ -1020,9 +881,6 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, out: i_mmap_unlock_read(mapping); - if (buffer_unwritten(&bh)) - complete_unwritten(&bh, !(result & VM_FAULT_ERROR)); - return result; fallback: @@ -1042,8 +900,7 @@ EXPORT_SYMBOL_GPL(__dax_pmd_fault); * pmd_fault handler for DAX files. */ int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, - pmd_t *pmd, unsigned int flags, get_block_t get_block, - dax_iodone_t complete_unwritten) + pmd_t *pmd, unsigned int flags, get_block_t get_block) { int result; struct super_block *sb = file_inode(vma->vm_file)->i_sb; @@ -1052,8 +909,7 @@ int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, sb_start_pagefault(sb); file_update_time(vma->vm_file); } - result = __dax_pmd_fault(vma, address, pmd, flags, get_block, - complete_unwritten); + result = __dax_pmd_fault(vma, address, pmd, flags, get_block); if (flags & FAULT_FLAG_WRITE) sb_end_pagefault(sb); @@ -1091,6 +947,43 @@ int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) } EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); +static bool dax_range_is_aligned(struct block_device *bdev, + unsigned int offset, unsigned int length) +{ + unsigned short sector_size = bdev_logical_block_size(bdev); + + if (!IS_ALIGNED(offset, sector_size)) + return false; + if (!IS_ALIGNED(length, sector_size)) + return false; + + return true; +} + +int __dax_zero_page_range(struct block_device *bdev, sector_t sector, + unsigned int offset, unsigned int length) +{ + struct blk_dax_ctl dax = { + .sector = sector, + .size = PAGE_SIZE, + }; + + if (dax_range_is_aligned(bdev, offset, length)) { + sector_t start_sector = dax.sector + (offset >> 9); + + return blkdev_issue_zeroout(bdev, start_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; +} +EXPORT_SYMBOL_GPL(__dax_zero_page_range); + /** * dax_zero_page_range - zero a range within a page of a DAX file * @inode: The file being truncated @@ -1102,12 +995,6 @@ EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); * 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) @@ -1126,23 +1013,11 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, bh.b_bdev = inode->i_sb->s_bdev; bh.b_size = PAGE_SIZE; err = get_block(inode, index, &bh, 0); - if (err < 0) + if (err < 0 || !buffer_written(&bh)) return err; - if (buffer_written(&bh)) { - struct block_device *bdev = bh.b_bdev; - struct blk_dax_ctl dax = { - .sector = to_sector(&bh, inode), - .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); - } - - return 0; + return __dax_zero_page_range(bh.b_bdev, to_sector(&bh, inode), + offset, length); } EXPORT_SYMBOL_GPL(dax_zero_page_range); @@ -1154,12 +1029,6 @@ 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) { diff --git a/fs/ext2/file.c b/fs/ext2/file.c index c1400b109805..868c02317b05 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -51,7 +51,7 @@ static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) } down_read(&ei->dax_sem); - ret = __dax_fault(vma, vmf, ext2_get_block, NULL); + ret = __dax_fault(vma, vmf, ext2_get_block); up_read(&ei->dax_sem); if (vmf->flags & FAULT_FLAG_WRITE) @@ -72,7 +72,7 @@ static int ext2_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, } down_read(&ei->dax_sem); - ret = __dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block, NULL); + ret = __dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block); up_read(&ei->dax_sem); if (flags & FAULT_FLAG_WRITE) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index b675610391b8..fcbe58641e40 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -737,19 +738,18 @@ 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), count, + GFP_NOFS); if (err) { mutex_unlock(&ei->truncate_mutex); goto cleanup; } - } + } else + set_buffer_new(bh_result); ext2_splice_branch(inode, iblock, partial, indirect_blks, count); mutex_unlock(&ei->truncate_mutex); - set_buffer_new(bh_result); got_it: map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); if (count > blocks_to_boundary) diff --git a/fs/ext2/super.c b/fs/ext2/super.c index b78caf25f746..1d9379568aa8 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -922,16 +922,9 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) blocksize = BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size); if (sbi->s_mount_opt & EXT2_MOUNT_DAX) { - if (blocksize != PAGE_SIZE) { - ext2_msg(sb, KERN_ERR, - "error: unsupported blocksize for dax"); + err = bdev_dax_supported(sb, blocksize); + if (err) goto failed_mount; - } - if (!sb->s_bdev->bd_disk->fops->direct_access) { - ext2_msg(sb, KERN_ERR, - "error: device does not support dax"); - goto failed_mount; - } } /* If the blocksize doesn't match, re-read the thing.. */ diff --git a/fs/ext4/file.c b/fs/ext4/file.c index d478110c32a6..df44c877892a 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -202,7 +202,7 @@ static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) if (IS_ERR(handle)) result = VM_FAULT_SIGBUS; else - result = __dax_fault(vma, vmf, ext4_dax_get_block, NULL); + result = __dax_fault(vma, vmf, ext4_dax_get_block); if (write) { if (!IS_ERR(handle)) @@ -238,7 +238,7 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, result = VM_FAULT_SIGBUS; else result = __dax_pmd_fault(vma, addr, pmd, flags, - ext4_dax_get_block, NULL); + ext4_dax_get_block); if (write) { if (!IS_ERR(handle)) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 20c5d52253b4..3822a5aedc61 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3417,16 +3417,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } if (sbi->s_mount_opt & EXT4_MOUNT_DAX) { - if (blocksize != PAGE_SIZE) { - ext4_msg(sb, KERN_ERR, - "error: unsupported blocksize for dax"); + err = bdev_dax_supported(sb, blocksize); + if (err) goto failed_mount; - } - if (!sb->s_bdev->bd_disk->fops->direct_access) { - ext4_msg(sb, KERN_ERR, - "error: device does not support dax"); - goto failed_mount; - } } if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) { diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 613ea2d7ac19..586bb64e674b 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/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 44af22897c8b..47fc63295422 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1551,7 +1551,7 @@ xfs_filemap_page_mkwrite( xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (IS_DAX(inode)) { - ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault, NULL); + ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault); } else { ret = block_page_mkwrite(vma, vmf, xfs_get_blocks); ret = block_page_mkwrite_return(ret); @@ -1585,7 +1585,7 @@ xfs_filemap_fault( * changes to xfs_get_blocks_direct() to map unwritten extent * ioend for conversion on read-only mappings. */ - ret = __dax_fault(vma, vmf, xfs_get_blocks_dax_fault, NULL); + ret = __dax_fault(vma, vmf, xfs_get_blocks_dax_fault); } else ret = filemap_fault(vma, vmf); xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); @@ -1622,8 +1622,7 @@ xfs_filemap_pmd_fault( } xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); - ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault, - NULL); + ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault); xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); if (flags & FAULT_FLAG_WRITE) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 416421d7ff10..11ea5d51db56 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1555,14 +1555,12 @@ xfs_fs_fill_super( if (mp->m_flags & XFS_MOUNT_DAX) { xfs_warn(mp, - "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); - if (sb->s_blocksize != PAGE_SIZE) { + "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); + + error = bdev_dax_supported(sb, sb->s_blocksize); + if (error) { xfs_alert(mp, - "Filesystem block size invalid for DAX Turning DAX off."); - mp->m_flags &= ~XFS_MOUNT_DAX; - } else if (!sb->s_bdev->bd_disk->fops->direct_access) { - xfs_alert(mp, - "Block device does not support DAX Turning DAX off."); + "DAX unsupported by block device. Turning off DAX."); mp->m_flags &= ~XFS_MOUNT_DAX; } } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1fd8fdff2f81..3d9cf326574f 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -768,6 +768,17 @@ static inline void rq_flush_dcache_pages(struct request *rq) } #endif +#ifdef CONFIG_PRINTK +#define vfs_msg(sb, level, fmt, ...) \ + __vfs_msg(sb, level, fmt, ##__VA_ARGS__) +#else +#define vfs_msg(sb, level, fmt, ...) \ +do { \ + no_printk(fmt, ##__VA_ARGS__); \ + __vfs_msg(sb, "", " "); \ +} while (0) +#endif + extern int blk_register_queue(struct gendisk *disk); extern void blk_unregister_queue(struct gendisk *disk); extern blk_qc_t generic_make_request(struct bio *bio); @@ -1660,7 +1671,7 @@ 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 */ @@ -1680,6 +1691,8 @@ extern int bdev_read_page(struct block_device *, sector_t, struct page *); extern int bdev_write_page(struct block_device *, sector_t, struct page *, struct writeback_control *); extern long bdev_direct_access(struct block_device *, struct blk_dax_ctl *); +extern int bdev_dax_supported(struct super_block *, int); +extern bool bdev_dax_capable(struct block_device *); #else /* CONFIG_BLOCK */ struct block_device; diff --git a/include/linux/dax.h b/include/linux/dax.h index 982a6c4a62f3..7743e51f826c 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -7,41 +7,44 @@ ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, 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, - dax_iodone_t); -int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t, - dax_iodone_t); +int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); +int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); #ifdef CONFIG_FS_DAX struct page *read_dax_sector(struct block_device *bdev, sector_t n); +int __dax_zero_page_range(struct block_device *bdev, sector_t sector, + unsigned int offset, unsigned int length); #else static inline struct page *read_dax_sector(struct block_device *bdev, sector_t n) { return ERR_PTR(-ENXIO); } +static inline int __dax_zero_page_range(struct block_device *bdev, + sector_t sector, unsigned int offset, unsigned int length) +{ + return -ENXIO; +} #endif #ifdef CONFIG_TRANSPARENT_HUGEPAGE int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *, - unsigned int flags, get_block_t, dax_iodone_t); + unsigned int flags, get_block_t); int __dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *, - unsigned int flags, get_block_t, dax_iodone_t); + unsigned int flags, get_block_t); #else static inline int dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, - pmd_t *pmd, unsigned int flags, get_block_t gb, - dax_iodone_t di) + pmd_t *pmd, unsigned int flags, get_block_t gb) { return VM_FAULT_FALLBACK; } #define __dax_pmd_fault dax_pmd_fault #endif int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *); -#define dax_mkwrite(vma, vmf, gb, iod) dax_fault(vma, vmf, gb, iod) -#define __dax_mkwrite(vma, vmf, gb, iod) __dax_fault(vma, vmf, gb, iod) +#define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb) +#define __dax_mkwrite(vma, vmf, gb) __dax_fault(vma, vmf, gb) static inline bool vma_is_dax(struct vm_area_struct *vma) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 5f61431d8673..9ace7f745bcd 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -74,7 +74,6 @@ typedef int (get_block_t)(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create); typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, ssize_t bytes, void *private); -typedef void (dax_iodone_t)(struct buffer_head *bh_map, int uptodate); #define MAY_EXEC 0x00000001 #define MAY_WRITE 0x00000002