| Message ID | 1669908538-55-3-git-send-email-ruansy.fnst@fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fsdax,xfs: fix warning messages | expand |
On Thu, Dec 01, 2022 at 03:28:52PM +0000, Shiyang Ruan wrote: > 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(). > > Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Looks ok, Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/dax.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index 85b81963ea31..482dda85ccaf 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -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) > -- > 2.38.1 >
diff --git a/fs/dax.c b/fs/dax.c index 85b81963ea31..482dda85ccaf 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -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)
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(). Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> --- fs/dax.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-)