From: Dan Williams Date: Fri, 30 Mar 2018 00:22:13 +0000 (-0700) Subject: dax, dm: allow device-mapper to operate without dax support X-Git-Tag: v4.19~1239^2^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=976431b02c2ef92ae3f8b6a7d699fc554025e118;p=platform%2Fkernel%2Flinux-rpi.git 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 --- diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 2c8ac36..edff083 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -201,7 +201,7 @@ config BLK_DEV_DM_BUILTIN config BLK_DEV_DM tristate "Device mapper support" select BLK_DEV_DM_BUILTIN - select DAX + depends on DAX || DAX=n ---help--- Device-mapper is a low level volume manager. It works by allowing people to specify mappings for ranges of logical sectors. Various diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index d5f8eff..89443e0 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -154,6 +154,7 @@ static int linear_iterate_devices(struct dm_target *ti, return fn(ti, lc->dev, lc->start, ti->len, data); } +#if IS_ENABLED(CONFIG_DAX_DRIVER) static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) { @@ -184,6 +185,11 @@ static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff, return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i); } +#else +#define linear_dax_direct_access NULL +#define linear_dax_copy_from_iter NULL +#endif + static struct target_type linear_target = { .name = "linear", .version = {1, 4, 0}, diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c index 3362d86..7fcb421 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", diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index b5e8921..ac2e8ee 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -311,6 +311,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio) return DM_MAPIO_REMAPPED; } +#if IS_ENABLED(CONFIG_DAX_DRIVER) static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) { @@ -351,6 +352,11 @@ static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff, return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i); } +#else +#define stripe_dax_direct_access NULL +#define stripe_dax_copy_from_iter NULL +#endif + /* * Stripe status: * diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 6813680..ffc93ae 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1800,7 +1800,7 @@ static void cleanup_mapped_device(struct mapped_device *md) static struct mapped_device *alloc_dev(int minor) { int r, numa_node_id = dm_get_numa_node(); - struct dax_device *dax_dev; + struct dax_device *dax_dev = NULL; struct mapped_device *md; void *old_md; @@ -1866,9 +1866,11 @@ static struct mapped_device *alloc_dev(int minor) md->disk->private_data = md; sprintf(md->disk->disk_name, "dm-%d", minor); - dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops); - if (!dax_dev) - goto bad; + if (IS_ENABLED(CONFIG_DAX_DRIVER)) { + dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops); + if (!dax_dev) + goto bad; + } md->dax_dev = dax_dev; add_disk_no_queue_reg(md->disk); diff --git a/include/linux/dax.h b/include/linux/dax.h index ae27a7e..f9eb22a 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -26,16 +26,39 @@ extern struct attribute_group dax_attribute_group; #if IS_ENABLED(CONFIG_DAX) struct dax_device *dax_get_by_host(const char *host); +struct dax_device *alloc_dax(void *private, const char *host, + const struct dax_operations *ops); void put_dax(struct dax_device *dax_dev); +void kill_dax(struct dax_device *dax_dev); +void dax_write_cache(struct dax_device *dax_dev, bool wc); +bool dax_write_cache_enabled(struct dax_device *dax_dev); #else static inline struct dax_device *dax_get_by_host(const char *host) { return NULL; } - +static inline struct dax_device *alloc_dax(void *private, const char *host, + const struct dax_operations *ops) +{ + /* + * Callers should check IS_ENABLED(CONFIG_DAX) to know if this + * NULL is an error or expected. + */ + return NULL; +} static inline void put_dax(struct dax_device *dax_dev) { } +static inline void kill_dax(struct dax_device *dax_dev) +{ +} +static inline void dax_write_cache(struct dax_device *dax_dev, bool wc) +{ +} +static inline bool dax_write_cache_enabled(struct dax_device *dax_dev) +{ + return false; +} #endif struct writeback_control; @@ -89,18 +112,13 @@ static inline int dax_writeback_mapping_range(struct address_space *mapping, int dax_read_lock(void); void dax_read_unlock(int id); -struct dax_device *alloc_dax(void *private, const char *host, - const struct dax_operations *ops); bool dax_alive(struct dax_device *dax_dev); -void kill_dax(struct dax_device *dax_dev); void *dax_get_private(struct dax_device *dax_dev); long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn); size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); -void dax_write_cache(struct dax_device *dax_dev, bool wc); -bool dax_write_cache_enabled(struct dax_device *dax_dev); ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops);