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authorLinus Torvalds <torvalds@linux-foundation.org>2020-09-20 15:01:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-09-20 15:01:57 -0700
commit4a123dbaf3a6efca717e3a5ac8176fd4897456b2 (patch)
tree3f935ae02d044652b14b7c39ab6e893fcd4e3028
parentbdcf11de8f776152c82d2197b255c2d04603f976 (diff)
parentd4c5da5049ac27c6ef8f6f98548c3a1ade352d25 (diff)
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Merge tag 'libnvdimm-fixes-5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams: "A handful of fixes to address a string of mistakes in the mechanism for device-mapper to determine if its component devices are dax capable. - Fix an original bug in device-mapper table reference counting when interrogating dax capability in the component device. This bug was hidden by the following bug. - Fix device-mapper to use the proper helper (dax_supported() instead of the leaf helper generic_fsdax_supported()) to determine dax operation of a stacked block device configuration. The original implementation is only valid for one level of dax-capable block device stacking. This bug was discovered while fixing the below regression. - Fix an infinite recursion regression introduced by broken attempts to quiet the generic_fsdax_supported() path and make it bail out before logging "dax capability not found" errors" * tag 'libnvdimm-fixes-5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: Fix stack overflow when mounting fsdax pmem device dm: Call proper helper to determine dax support dm/dax: Fix table reference counts
-rw-r--r--drivers/dax/super.c16
-rw-r--r--drivers/md/dm-table.c10
-rw-r--r--drivers/md/dm.c5
-rw-r--r--include/linux/dax.h22
4 files changed, 40 insertions, 13 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index e5767c83ea23..e84070b55463 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -85,6 +85,12 @@ bool __generic_fsdax_supported(struct dax_device *dax_dev,
return false;
}
+ if (!dax_dev) {
+ pr_debug("%s: error: dax unsupported by block device\n",
+ bdevname(bdev, buf));
+ return false;
+ }
+
err = bdev_dax_pgoff(bdev, start, PAGE_SIZE, &pgoff);
if (err) {
pr_info("%s: error: unaligned partition for dax\n",
@@ -100,12 +106,6 @@ bool __generic_fsdax_supported(struct dax_device *dax_dev,
return false;
}
- if (!dax_dev || !bdev_dax_supported(bdev, blocksize)) {
- pr_debug("%s: error: dax unsupported by block device\n",
- bdevname(bdev, buf));
- return false;
- }
-
id = dax_read_lock();
len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn);
len2 = dax_direct_access(dax_dev, pgoff_end, 1, &end_kaddr, &end_pfn);
@@ -325,11 +325,15 @@ EXPORT_SYMBOL_GPL(dax_direct_access);
bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
int blocksize, sector_t start, sector_t len)
{
+ if (!dax_dev)
+ return false;
+
if (!dax_alive(dax_dev))
return false;
return dax_dev->ops->dax_supported(dax_dev, bdev, blocksize, start, len);
}
+EXPORT_SYMBOL_GPL(dax_supported);
size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
size_t bytes, struct iov_iter *i)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 5edc3079e7c1..229f461e7def 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -860,10 +860,14 @@ EXPORT_SYMBOL_GPL(dm_table_set_type);
int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
- int blocksize = *(int *) data;
+ int blocksize = *(int *) data, id;
+ bool rc;
- return generic_fsdax_supported(dev->dax_dev, dev->bdev, blocksize,
- start, len);
+ id = dax_read_lock();
+ rc = dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
+ dax_read_unlock(id);
+
+ return rc;
}
/* Check devices support synchronous DAX */
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index fb0255d25e4b..4a40df8af7d3 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1136,15 +1136,16 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd
{
struct mapped_device *md = dax_get_private(dax_dev);
struct dm_table *map;
+ bool ret = false;
int srcu_idx;
- bool ret;
map = dm_get_live_table(md, &srcu_idx);
if (!map)
- return false;
+ goto out;
ret = dm_table_supports_dax(map, device_supports_dax, &blocksize);
+out:
dm_put_live_table(md, srcu_idx);
return ret;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 6904d4e0b2e0..497031392e0a 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -130,6 +130,8 @@ static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
return __generic_fsdax_supported(dax_dev, bdev, blocksize, start,
sectors);
}
+bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
+ int blocksize, sector_t start, sector_t len);
static inline void fs_put_dax(struct dax_device *dax_dev)
{
@@ -157,6 +159,13 @@ static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
return false;
}
+static inline bool dax_supported(struct dax_device *dax_dev,
+ struct block_device *bdev, int blocksize, sector_t start,
+ sector_t len)
+{
+ return false;
+}
+
static inline void fs_put_dax(struct dax_device *dax_dev)
{
}
@@ -189,14 +198,23 @@ static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
}
#endif
+#if IS_ENABLED(CONFIG_DAX)
int dax_read_lock(void);
void dax_read_unlock(int id);
+#else
+static inline int dax_read_lock(void)
+{
+ return 0;
+}
+
+static inline void dax_read_unlock(int id)
+{
+}
+#endif /* CONFIG_DAX */
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,