From 5916a22b83041b07d63191fe06206ae0fff6ec7a Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 22 Jun 2017 11:32:45 -0700 Subject: dm: constify argument arrays The arrays of 'struct dm_arg' are never modified by the device-mapper core, so constify them so that they are placed in .rodata. (Exception: the args array in dm-raid cannot be constified because it is allocated on the stack and modified.) Signed-off-by: Eric Biggers Signed-off-by: Mike Snitzer --- include/linux/device-mapper.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 4f2b3b2076c4..3b5fdf308148 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -387,7 +387,7 @@ struct dm_arg { * Validate the next argument, either returning it as *value or, if invalid, * returning -EINVAL and setting *error. */ -int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set, +int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set, unsigned *value, char **error); /* @@ -395,7 +395,7 @@ int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set, * arg->min and arg->max further arguments. Either return the size as * *num_args or, if invalid, return -EINVAL and set *error. */ -int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set, +int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set, unsigned *num_args, char **error); /* -- cgit From c3ca015fab6df124c933b91902f3f2a3473f9da5 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 31 Aug 2017 21:47:43 -0400 Subject: dax: remove the pmem_dax_ops->flush abstraction Commit abebfbe2f731 ("dm: add ->flush() dax operation support") is buggy. A DM device may be composed of multiple underlying devices and all of them need to be flushed. That commit just routes the flush request to the first device and ignores the other devices. It could be fixed by adding more complex logic to the device mapper. But there is only one implementation of the method pmem_dax_ops->flush - that is pmem_dax_flush() - and it calls arch_wb_cache_pmem(). Consequently, we don't need the pmem_dax_ops->flush abstraction at all, we can call arch_wb_cache_pmem() directly from dax_flush() because dax_dev->ops->flush can't ever reach anything different from arch_wb_cache_pmem(). It should be also pointed out that for some uses of persistent memory it is needed to flush only a very small amount of data (such as 1 cacheline), and it would be overkill if we go through that device mapper machinery for a single flushed cache line. Fix this by removing the pmem_dax_ops->flush abstraction and call arch_wb_cache_pmem() directly from dax_flush(). Also, remove the device mapper code that forwards the flushes. Fixes: abebfbe2f731 ("dm: add ->flush() dax operation support") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Reviewed-by: Dan Williams Signed-off-by: Mike Snitzer --- include/linux/dax.h | 5 +---- include/linux/device-mapper.h | 3 --- 2 files changed, 1 insertion(+), 7 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dax.h b/include/linux/dax.h index df97b7af7e2c..0d8f35f6c53d 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -19,8 +19,6 @@ struct dax_operations { /* copy_from_iter: required operation for fs-dax direct-i/o */ size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t, struct iov_iter *); - /* flush: optional driver-specific cache management after writes */ - void (*flush)(struct dax_device *, pgoff_t, void *, size_t); }; extern struct attribute_group dax_attribute_group; @@ -84,8 +82,7 @@ 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, pgoff_t pgoff, void *addr, - size_t size); +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); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 3b5fdf308148..a5538433c927 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -134,8 +134,6 @@ typedef long (*dm_dax_direct_access_fn) (struct dm_target *ti, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn); typedef size_t (*dm_dax_copy_from_iter_fn)(struct dm_target *ti, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); -typedef void (*dm_dax_flush_fn)(struct dm_target *ti, pgoff_t pgoff, void *addr, - size_t size); #define PAGE_SECTORS (PAGE_SIZE / 512) void dm_error(const char *message); @@ -186,7 +184,6 @@ struct target_type { dm_io_hints_fn io_hints; dm_dax_direct_access_fn direct_access; dm_dax_copy_from_iter_fn dax_copy_from_iter; - dm_dax_flush_fn dax_flush; /* For internal device-mapper use. */ struct list_head list; -- cgit