diff options
| author | Shiyang Ruan <ruansy.fnst@fujitsu.com> | 2022-12-01 15:28:52 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-12-11 18:12:16 -0800 |
| commit | f80e1668888f34c0764822e74953c997daf2ccdb (patch) | |
| tree | 736491b9ee73e4603e4795e716927e572b4961e6 | |
| parent | 169004265860327182ecf92297b25b6271e81e96 (diff) | |
fsdax: invalidate pages when CoW
CoW changes the share state of a dax page, but the share count of the page
isn't updated. The next time access this page, it should have been a
newly accessed, but old association exists. So, we need to clear the
share state when CoW happens, in both dax_iomap_rw() and dax_zero_iter().
Link: https://lkml.kernel.org/r/1669908538-55-3-git-send-email-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/dax.c | 17 |
1 files changed, 13 insertions, 4 deletions
@@ -1264,6 +1264,15 @@ static s64 dax_zero_iter(struct iomap_iter *iter, bool *did_zero) if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN) return length; + /* + * invalidate the pages whose sharing state is to be changed + * because of CoW. + */ + if (iomap->flags & IOMAP_F_SHARED) + invalidate_inode_pages2_range(iter->inode->i_mapping, + pos >> PAGE_SHIFT, + (pos + length - 1) >> PAGE_SHIFT); + do { unsigned offset = offset_in_page(pos); unsigned size = min_t(u64, PAGE_SIZE - offset, length); @@ -1324,12 +1333,13 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi, struct iov_iter *iter) { const struct iomap *iomap = &iomi->iomap; - const struct iomap *srcmap = &iomi->srcmap; + const struct iomap *srcmap = iomap_iter_srcmap(iomi); loff_t length = iomap_length(iomi); loff_t pos = iomi->pos; struct dax_device *dax_dev = iomap->dax_dev; loff_t end = pos + length, done = 0; bool write = iov_iter_rw(iter) == WRITE; + bool cow = write && iomap->flags & IOMAP_F_SHARED; ssize_t ret = 0; size_t xfer; int id; @@ -1356,7 +1366,7 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi, * into page tables. We have to tear down these mappings so that data * written by write(2) is visible in mmap. */ - if (iomap->flags & IOMAP_F_NEW) { + if (iomap->flags & IOMAP_F_NEW || cow) { invalidate_inode_pages2_range(iomi->inode->i_mapping, pos >> PAGE_SHIFT, (end - 1) >> PAGE_SHIFT); @@ -1390,8 +1400,7 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi, break; } - if (write && - srcmap->type != IOMAP_HOLE && srcmap->addr != iomap->addr) { + if (cow) { ret = dax_iomap_cow_copy(pos, length, PAGE_SIZE, srcmap, kaddr); if (ret) |