This patch adds 'DAXDEV_SYNC' flag which is set for nd_region doing synchronous flush. This later is used to disable MAP_SYNC functionality for ext4 & xfs filesystem for devices don't support synchronous flush. Signed-off-by: Pankaj Gupta <pagupta@xxxxxxxxxx> --- drivers/dax/bus.c | 2 +- drivers/dax/super.c | 13 ++++++++++++- drivers/md/dm.c | 2 +- drivers/nvdimm/pmem.c | 3 ++- drivers/nvdimm/region_devs.c | 7 +++++++ include/linux/dax.h | 9 +++++++-- include/linux/libnvdimm.h | 1 + 7 files changed, 31 insertions(+), 6 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 2109cfe80219..431bf7d2a7f9 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -388,7 +388,7 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id, * No 'host' or dax_operations since there is no access to this * device outside of mmap of the resulting character device. */ - dax_dev = alloc_dax(dev_dax, NULL, NULL); + dax_dev = alloc_dax(dev_dax, NULL, NULL, true); if (!dax_dev) goto err; diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 0a339b85133e..bd6509308d05 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -186,6 +186,8 @@ enum dax_device_flags { DAXDEV_ALIVE, /* gate whether dax_flush() calls the low level flush routine */ DAXDEV_WRITE_CACHE, + /* flag to check if device supports synchronous flush */ + DAXDEV_SYNC, }; /** @@ -354,6 +356,12 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev) } EXPORT_SYMBOL_GPL(dax_write_cache_enabled); +bool dax_synchronous(struct dax_device *dax_dev) +{ + return test_bit(DAXDEV_SYNC, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_synchronous); + bool dax_alive(struct dax_device *dax_dev) { lockdep_assert_held(&dax_srcu); @@ -511,7 +519,7 @@ static void dax_add_host(struct dax_device *dax_dev, const char *host) } struct dax_device *alloc_dax(void *private, const char *__host, - const struct dax_operations *ops) + const struct dax_operations *ops, bool sync) { struct dax_device *dax_dev; const char *host; @@ -534,6 +542,9 @@ struct dax_device *alloc_dax(void *private, const char *__host, dax_add_host(dax_dev, host); dax_dev->ops = ops; dax_dev->private = private; + if (sync) + set_bit(DAXDEV_SYNC, &dax_dev->flags); + return dax_dev; err_dev: diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 68d24056d0b1..534e12ca6329 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1965,7 +1965,7 @@ static struct mapped_device *alloc_dev(int minor) sprintf(md->disk->disk_name, "dm-%d", minor); if (IS_ENABLED(CONFIG_DAX_DRIVER)) { - dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops); + dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops, true); if (!dax_dev) goto bad; } diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 5a5b3ea4d073..78f71ba0e7cf 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -466,7 +466,8 @@ static int pmem_attach_disk(struct device *dev, nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res); disk->bb = &pmem->bb; - dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops); + dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, + is_nvdimm_sync(nd_region)); if (!dax_dev) { put_disk(disk); diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index fb1041ab32a6..8c7aa047fe2b 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -1231,6 +1231,13 @@ int nvdimm_has_cache(struct nd_region *nd_region) } EXPORT_SYMBOL_GPL(nvdimm_has_cache); +bool is_nvdimm_sync(struct nd_region *nd_region) +{ + return is_nd_pmem(&nd_region->dev) && + !test_bit(ND_REGION_ASYNC, &nd_region->flags); +} +EXPORT_SYMBOL_GPL(is_nvdimm_sync); + struct conflict_context { struct nd_region *nd_region; resource_size_t start, size; diff --git a/include/linux/dax.h b/include/linux/dax.h index 0dd316a74a29..b896706a5ee9 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -32,18 +32,19 @@ 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); + const struct dax_operations *ops, bool sync); 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); +bool dax_synchronous(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) + const struct dax_operations *ops, bool sync) { /* * Callers should check IS_ENABLED(CONFIG_DAX) to know if this @@ -64,6 +65,10 @@ static inline bool dax_write_cache_enabled(struct dax_device *dax_dev) { return false; } +static inline bool dax_synchronous(struct dax_device *dax_dev) +{ + return true; +} #endif struct writeback_control; diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h index d9d2ab8a6e64..9a8aea370cbc 100644 --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -270,6 +270,7 @@ int generic_nvdimm_flush(struct nd_region *nd_region); int nvdimm_has_flush(struct nd_region *nd_region); int nvdimm_has_cache(struct nd_region *nd_region); int nvdimm_in_overwrite(struct nvdimm *nvdimm); +bool is_nvdimm_sync(struct nd_region *nd_region); static inline int nvdimm_ctl(struct nvdimm *nvdimm, unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc) -- 2.20.1