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| author | Dan Williams <dan.j.williams@intel.com> | 2019-05-16 22:26:29 +0200 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2019-05-21 00:02:08 +0200 |
| commit | 7bf7eac8d648057519adb6fce1e31458c902212c (patch) | |
| tree | 1d4489b03dd6ef2526c41de62d525fdc5a1842ea /include | |
| parent | libnvdimm: Fix compilation warnings with W=1 (diff) | |
| download | linux-7bf7eac8d648057519adb6fce1e31458c902212c.tar.xz linux-7bf7eac8d648057519adb6fce1e31458c902212c.zip | |
dax: Arrange for dax_supported check to span multiple devices
Pankaj reports that starting with commit ad428cdb525a "dax: Check the
end of the block-device capacity with dax_direct_access()" device-mapper
no longer allows dax operation. This results from the stricter checks in
__bdev_dax_supported() that validate that the start and end of a
block-device map to the same 'pagemap' instance.
Teach the dax-core and device-mapper to validate the 'pagemap' on a
per-target basis. This is accomplished by refactoring the
bdev_dax_supported() internals into generic_fsdax_supported() which
takes a sector range to validate. Consequently generic_fsdax_supported()
is suitable to be used in a device-mapper ->iterate_devices() callback.
A new ->dax_supported() operation is added to allow composite devices to
split and route upper-level bdev_dax_supported() requests.
Fixes: ad428cdb525a ("dax: Check the end of the block-device...")
Cc: <stable@vger.kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reported-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Tested-by: Pankaj Gupta <pagupta@redhat.com>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/dax.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/dax.h b/include/linux/dax.h index 0dd316a74a29..becaea5f4488 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -19,6 +19,12 @@ struct dax_operations { */ long (*direct_access)(struct dax_device *, pgoff_t, long, void **, pfn_t *); + /* + * Validate whether this device is usable as an fsdax backing + * device. + */ + bool (*dax_supported)(struct dax_device *, struct block_device *, int, + sector_t, sector_t); /* 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 *); @@ -75,6 +81,17 @@ static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize) return __bdev_dax_supported(bdev, blocksize); } +bool __generic_fsdax_supported(struct dax_device *dax_dev, + struct block_device *bdev, int blocksize, sector_t start, + sector_t sectors); +static inline bool generic_fsdax_supported(struct dax_device *dax_dev, + struct block_device *bdev, int blocksize, sector_t start, + sector_t sectors) +{ + return __generic_fsdax_supported(dax_dev, bdev, blocksize, start, + sectors); +} + static inline struct dax_device *fs_dax_get_by_host(const char *host) { return dax_get_by_host(host); @@ -99,6 +116,13 @@ static inline bool bdev_dax_supported(struct block_device *bdev, return false; } +static inline bool generic_fsdax_supported(struct dax_device *dax_dev, + struct block_device *bdev, int blocksize, sector_t start, + sector_t sectors) +{ + return false; +} + static inline struct dax_device *fs_dax_get_by_host(const char *host) { return NULL; @@ -142,6 +166,8 @@ bool dax_alive(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); +bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev, + int blocksize, sector_t start, sector_t len); size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, |