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authorJane Chu <jane.chu@oracle.com>2022-04-22 16:45:06 -0600
committerDan Williams <dan.j.williams@intel.com>2022-05-16 13:37:59 -0700
commit047218ec904da19c45c4a70274fc3f818a1fcba1 (patch)
tree6602586a5cbfa59b34a6699c920a0d4e7ad7dac8 /fs/dax.c
parente511c4a3d2a1f64aafc1f5df37a2ffcf7ef91b55 (diff)
dax: add .recovery_write dax_operation
Introduce dax_recovery_write() operation. The function is used to recover a dax range that contains poison. Typical use case is when a user process receives a SIGBUS with si_code BUS_MCEERR_AR indicating poison(s) in a dax range, in response, the user process issues a pwrite() to the page-aligned dax range, thus clears the poison and puts valid data in the range. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jane Chu <jane.chu@oracle.com> Link: https://lore.kernel.org/r/20220422224508.440670-6-jane.chu@oracle.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'fs/dax.c')
-rw-r--r--fs/dax.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/fs/dax.c b/fs/dax.c
index ef3103107104..a1e4b45cbf55 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1240,6 +1240,7 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
const size_t size = ALIGN(length + offset, PAGE_SIZE);
pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);
ssize_t map_len;
+ bool recovery = false;
void *kaddr;
if (fatal_signal_pending(current)) {
@@ -1249,6 +1250,13 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
map_len = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size),
DAX_ACCESS, &kaddr, NULL);
+ if (map_len == -EIO && iov_iter_rw(iter) == WRITE) {
+ map_len = dax_direct_access(dax_dev, pgoff,
+ PHYS_PFN(size), DAX_RECOVERY_WRITE,
+ &kaddr, NULL);
+ if (map_len > 0)
+ recovery = true;
+ }
if (map_len < 0) {
ret = map_len;
break;
@@ -1260,7 +1268,10 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
if (map_len > end - pos)
map_len = end - pos;
- if (iov_iter_rw(iter) == WRITE)
+ if (recovery)
+ xfer = dax_recovery_write(dax_dev, pgoff, kaddr,
+ map_len, iter);
+ else if (iov_iter_rw(iter) == WRITE)
xfer = dax_copy_from_iter(dax_dev, pgoff, kaddr,
map_len, iter);
else