kmap_atomic() is deprecated and should be replaced with kmap_local_page() [1][2]. kmap_local_page() is faster in kernels with HIGHMEM enabled, can take page faults, and allows preemption. According to [2], this is safe as long as the code between kmap_atomic() and kunmap_atomic() does not implicitly depend on disabling page faults or preemption. It appears to me that none of the call sites in this patch depend on disabling page faults or preemption; they are all mapping a page to simply extract some information from it or print some debug info. [1] https://lwn.net/Articles/836144/ [2] https://docs.kernel.org/mm/highmem.html#temporary-virtual-mappings Signed-off-by: David Reaver <me@xxxxxxxxxxxxxxx> --- drivers/md/md-bitmap.c | 42 ++++++++++++++++++++-------------------- drivers/md/raid5-cache.c | 16 +++++++-------- 2 files changed, 29 insertions(+), 29 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index 29da10e6f703..1f8772b3b66c 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -682,7 +682,7 @@ static void bitmap_update_sb(void *data) return; if (!bitmap->storage.sb_page) /* no superblock */ return; - sb = kmap_atomic(bitmap->storage.sb_page); + sb = kmap_local_page(bitmap->storage.sb_page); sb->events = cpu_to_le64(bitmap->mddev->events); if (bitmap->mddev->events < bitmap->events_cleared) /* rocking back to read-only */ @@ -702,7 +702,7 @@ static void bitmap_update_sb(void *data) sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes); sb->sectors_reserved = cpu_to_le32(bitmap->mddev-> bitmap_info.space); - kunmap_atomic(sb); + kunmap_local(sb); if (bitmap->storage.file) write_file_page(bitmap, bitmap->storage.sb_page, 1); @@ -717,7 +717,7 @@ static void bitmap_print_sb(struct bitmap *bitmap) if (!bitmap || !bitmap->storage.sb_page) return; - sb = kmap_atomic(bitmap->storage.sb_page); + sb = kmap_local_page(bitmap->storage.sb_page); pr_debug("%s: bitmap file superblock:\n", bmname(bitmap)); pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic)); pr_debug(" version: %u\n", le32_to_cpu(sb->version)); @@ -736,7 +736,7 @@ static void bitmap_print_sb(struct bitmap *bitmap) pr_debug(" sync size: %llu KB\n", (unsigned long long)le64_to_cpu(sb->sync_size)/2); pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind)); - kunmap_atomic(sb); + kunmap_local(sb); } /* @@ -760,7 +760,7 @@ static int md_bitmap_new_disk_sb(struct bitmap *bitmap) return -ENOMEM; bitmap->storage.sb_index = 0; - sb = kmap_atomic(bitmap->storage.sb_page); + sb = kmap_local_page(bitmap->storage.sb_page); sb->magic = cpu_to_le32(BITMAP_MAGIC); sb->version = cpu_to_le32(BITMAP_MAJOR_HI); @@ -768,7 +768,7 @@ static int md_bitmap_new_disk_sb(struct bitmap *bitmap) chunksize = bitmap->mddev->bitmap_info.chunksize; BUG_ON(!chunksize); if (!is_power_of_2(chunksize)) { - kunmap_atomic(sb); + kunmap_local(sb); pr_warn("bitmap chunksize not a power of 2\n"); return -EINVAL; } @@ -803,7 +803,7 @@ static int md_bitmap_new_disk_sb(struct bitmap *bitmap) sb->events_cleared = cpu_to_le64(bitmap->mddev->events); bitmap->mddev->bitmap_info.nodes = 0; - kunmap_atomic(sb); + kunmap_local(sb); return 0; } @@ -865,7 +865,7 @@ static int md_bitmap_read_sb(struct bitmap *bitmap) return err; err = -EINVAL; - sb = kmap_atomic(sb_page); + sb = kmap_local_page(sb_page); chunksize = le32_to_cpu(sb->chunksize); daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ; @@ -932,7 +932,7 @@ static int md_bitmap_read_sb(struct bitmap *bitmap) err = 0; out: - kunmap_atomic(sb); + kunmap_local(sb); if (err == 0 && nodes && (bitmap->cluster_slot < 0)) { /* Assigning chunksize is required for "re_read" */ bitmap->mddev->bitmap_info.chunksize = chunksize; @@ -1161,12 +1161,12 @@ static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block) bit = file_page_offset(&bitmap->storage, chunk); /* set the bit */ - kaddr = kmap_atomic(page); + kaddr = kmap_local_page(page); if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags)) set_bit(bit, kaddr); else set_bit_le(bit, kaddr); - kunmap_atomic(kaddr); + kunmap_local(kaddr); pr_debug("set file bit %lu page %lu\n", bit, index); /* record page number so it gets flushed to disk when unplug occurs */ set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_DIRTY); @@ -1190,12 +1190,12 @@ static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block) if (!page) return; bit = file_page_offset(&bitmap->storage, chunk); - paddr = kmap_atomic(page); + paddr = kmap_local_page(page); if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags)) clear_bit(bit, paddr); else clear_bit_le(bit, paddr); - kunmap_atomic(paddr); + kunmap_local(paddr); if (!test_page_attr(bitmap, index - node_offset, BITMAP_PAGE_NEEDWRITE)) { set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_PENDING); bitmap->allclean = 0; @@ -1214,12 +1214,12 @@ static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block) if (!page) return -EINVAL; bit = file_page_offset(&bitmap->storage, chunk); - paddr = kmap_atomic(page); + paddr = kmap_local_page(page); if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags)) set = test_bit(bit, paddr); else set = test_bit_le(bit, paddr); - kunmap_atomic(paddr); + kunmap_local(paddr); return set; } @@ -1387,9 +1387,9 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) * If the bitmap is out of date, dirty the whole page * and write it out */ - paddr = kmap_atomic(page); + paddr = kmap_local_page(page); memset(paddr + offset, 0xff, PAGE_SIZE - offset); - kunmap_atomic(paddr); + kunmap_local(paddr); filemap_write_page(bitmap, i, true); if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) { @@ -1405,12 +1405,12 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) void *paddr; bool was_set; - paddr = kmap_atomic(page); + paddr = kmap_local_page(page); if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags)) was_set = test_bit(bit, paddr); else was_set = test_bit_le(bit, paddr); - kunmap_atomic(paddr); + kunmap_local(paddr); if (was_set) { /* if the disk bit is set, set the memory bit */ @@ -1545,10 +1545,10 @@ static void bitmap_daemon_work(struct mddev *mddev) bitmap_super_t *sb; bitmap->need_sync = 0; if (bitmap->storage.filemap) { - sb = kmap_atomic(bitmap->storage.sb_page); + sb = kmap_local_page(bitmap->storage.sb_page); sb->events_cleared = cpu_to_le64(bitmap->events_cleared); - kunmap_atomic(sb); + kunmap_local(sb); set_page_attr(bitmap, 0, BITMAP_PAGE_NEEDWRITE); } diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index b4f7b79fd187..7a22cb2e5ac3 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1023,10 +1023,10 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) /* checksum is already calculated in last run */ if (test_bit(STRIPE_LOG_TRAPPED, &sh->state)) continue; - addr = kmap_atomic(sh->dev[i].page); + addr = kmap_local_page(sh->dev[i].page); sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE); - kunmap_atomic(addr); + kunmap_local(addr); } parity_pages = 1 + !!(sh->qd_idx >= 0); data_pages = write_disks - parity_pages; @@ -1979,9 +1979,9 @@ r5l_recovery_verify_data_checksum(struct r5l_log *log, u32 checksum; r5l_recovery_read_page(log, ctx, page, log_offset); - addr = kmap_atomic(page); + addr = kmap_local_page(page); checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE); - kunmap_atomic(addr); + kunmap_local(addr); return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL; } @@ -2381,11 +2381,11 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log, payload->size = cpu_to_le32(BLOCK_SECTORS); payload->location = cpu_to_le64( raid5_compute_blocknr(sh, i, 0)); - addr = kmap_atomic(dev->page); + addr = kmap_local_page(dev->page); payload->checksum[0] = cpu_to_le32( crc32c_le(log->uuid_checksum, addr, PAGE_SIZE)); - kunmap_atomic(addr); + kunmap_local(addr); sync_page_io(log->rdev, write_pos, PAGE_SIZE, dev->page, REQ_OP_WRITE, false); write_pos = r5l_ring_add(log, write_pos, @@ -2888,10 +2888,10 @@ int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh) if (!test_bit(R5_Wantwrite, &sh->dev[i].flags)) continue; - addr = kmap_atomic(sh->dev[i].page); + addr = kmap_local_page(sh->dev[i].page); sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE); - kunmap_atomic(addr); + kunmap_local(addr); pages++; } WARN_ON(pages == 0);
