From 976431b02c2ef92ae3f8b6a7d699fc554025e118 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 29 Mar 2018 17:22:13 -0700 Subject: dax, dm: allow device-mapper to operate without dax support Change device-mapper's DAX dependency to require the presence of at least one DAX_DRIVER. This allows device-mapper to be built without bringing the DAX core along which is especially wasteful when there are no DAX drivers, like BLK_DEV_PMEM, configured. Cc: Alasdair Kergon Reported-by: Bart Van Assche Reported-by: kbuild test robot Reported-by: Arnd Bergmann Reviewed-by: Mike Snitzer Signed-off-by: Dan Williams --- drivers/md/dm-log-writes.c | 95 ++++++++++++++++++++++++---------------------- 1 file changed, 50 insertions(+), 45 deletions(-) (limited to 'drivers/md/dm-log-writes.c') diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c index 3362d866793b..7fcb4216973f 100644 --- a/drivers/md/dm-log-writes.c +++ b/drivers/md/dm-log-writes.c @@ -610,51 +610,6 @@ static int log_mark(struct log_writes_c *lc, char *data) return 0; } -static int log_dax(struct log_writes_c *lc, sector_t sector, size_t bytes, - struct iov_iter *i) -{ - struct pending_block *block; - - if (!bytes) - return 0; - - block = kzalloc(sizeof(struct pending_block), GFP_KERNEL); - if (!block) { - DMERR("Error allocating dax pending block"); - return -ENOMEM; - } - - block->data = kzalloc(bytes, GFP_KERNEL); - if (!block->data) { - DMERR("Error allocating dax data space"); - kfree(block); - return -ENOMEM; - } - - /* write data provided via the iterator */ - if (!copy_from_iter(block->data, bytes, i)) { - DMERR("Error copying dax data"); - kfree(block->data); - kfree(block); - return -EIO; - } - - /* rewind the iterator so that the block driver can use it */ - iov_iter_revert(i, bytes); - - block->datalen = bytes; - block->sector = bio_to_dev_sectors(lc, sector); - block->nr_sectors = ALIGN(bytes, lc->sectorsize) >> lc->sectorshift; - - atomic_inc(&lc->pending_blocks); - spin_lock_irq(&lc->blocks_lock); - list_add_tail(&block->list, &lc->unflushed_blocks); - spin_unlock_irq(&lc->blocks_lock); - wake_up_process(lc->log_kthread); - - return 0; -} - static void log_writes_dtr(struct dm_target *ti) { struct log_writes_c *lc = ti->private; @@ -920,6 +875,52 @@ static void log_writes_io_hints(struct dm_target *ti, struct queue_limits *limit limits->io_min = limits->physical_block_size; } +#if IS_ENABLED(CONFIG_DAX_DRIVER) +static int log_dax(struct log_writes_c *lc, sector_t sector, size_t bytes, + struct iov_iter *i) +{ + struct pending_block *block; + + if (!bytes) + return 0; + + block = kzalloc(sizeof(struct pending_block), GFP_KERNEL); + if (!block) { + DMERR("Error allocating dax pending block"); + return -ENOMEM; + } + + block->data = kzalloc(bytes, GFP_KERNEL); + if (!block->data) { + DMERR("Error allocating dax data space"); + kfree(block); + return -ENOMEM; + } + + /* write data provided via the iterator */ + if (!copy_from_iter(block->data, bytes, i)) { + DMERR("Error copying dax data"); + kfree(block->data); + kfree(block); + return -EIO; + } + + /* rewind the iterator so that the block driver can use it */ + iov_iter_revert(i, bytes); + + block->datalen = bytes; + block->sector = bio_to_dev_sectors(lc, sector); + block->nr_sectors = ALIGN(bytes, lc->sectorsize) >> lc->sectorshift; + + atomic_inc(&lc->pending_blocks); + spin_lock_irq(&lc->blocks_lock); + list_add_tail(&block->list, &lc->unflushed_blocks); + spin_unlock_irq(&lc->blocks_lock); + wake_up_process(lc->log_kthread); + + return 0; +} + static long log_writes_dax_direct_access(struct dm_target *ti, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) { @@ -956,6 +957,10 @@ static size_t log_writes_dax_copy_from_iter(struct dm_target *ti, dax_copy: return dax_copy_from_iter(lc->dev->dax_dev, pgoff, addr, bytes, i); } +#else +#define log_writes_dax_direct_access NULL +#define log_writes_dax_copy_from_iter NULL +#endif static struct target_type log_writes_target = { .name = "log-writes", -- cgit