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-rw-r--r--fs/dax.c45
-rw-r--r--fs/iomap/buffered-io.c30
-rw-r--r--fs/xfs/xfs_iomap.c2
-rw-r--r--include/linux/iomap.h1
4 files changed, 46 insertions, 32 deletions
diff --git a/fs/dax.c b/fs/dax.c
index c62acd2812f8..21b47402b3dc 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1262,35 +1262,46 @@ static s64 dax_unshare_iter(struct iomap_iter *iter)
{
struct iomap *iomap = &iter->iomap;
const struct iomap *srcmap = iomap_iter_srcmap(iter);
- loff_t pos = iter->pos;
- loff_t length = iomap_length(iter);
+ loff_t copy_pos = iter->pos;
+ u64 copy_len = iomap_length(iter);
+ u32 mod;
int id = 0;
s64 ret = 0;
void *daddr = NULL, *saddr = NULL;
- /* don't bother with blocks that are not shared to start with */
- if (!(iomap->flags & IOMAP_F_SHARED))
- return length;
+ if (!iomap_want_unshare_iter(iter))
+ return iomap_length(iter);
+
+ /*
+ * Extend the file range to be aligned to fsblock/pagesize, because
+ * we need to copy entire blocks, not just the byte range specified.
+ * Invalidate the mapping because we're about to CoW.
+ */
+ mod = offset_in_page(copy_pos);
+ if (mod) {
+ copy_len += mod;
+ copy_pos -= mod;
+ }
+
+ mod = offset_in_page(copy_pos + copy_len);
+ if (mod)
+ copy_len += PAGE_SIZE - mod;
+
+ invalidate_inode_pages2_range(iter->inode->i_mapping,
+ copy_pos >> PAGE_SHIFT,
+ (copy_pos + copy_len - 1) >> PAGE_SHIFT);
id = dax_read_lock();
- ret = dax_iomap_direct_access(iomap, pos, length, &daddr, NULL);
+ ret = dax_iomap_direct_access(iomap, copy_pos, copy_len, &daddr, NULL);
if (ret < 0)
goto out_unlock;
- /* zero the distance if srcmap is HOLE or UNWRITTEN */
- if (srcmap->flags & IOMAP_F_SHARED || srcmap->type == IOMAP_UNWRITTEN) {
- memset(daddr, 0, length);
- dax_flush(iomap->dax_dev, daddr, length);
- ret = length;
- goto out_unlock;
- }
-
- ret = dax_iomap_direct_access(srcmap, pos, length, &saddr, NULL);
+ ret = dax_iomap_direct_access(srcmap, copy_pos, copy_len, &saddr, NULL);
if (ret < 0)
goto out_unlock;
- if (copy_mc_to_kernel(daddr, saddr, length) == 0)
- ret = length;
+ if (copy_mc_to_kernel(daddr, saddr, copy_len) == 0)
+ ret = iomap_length(iter);
else
ret = -EIO;
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 78ebd265f425..3899169b2cf7 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1309,19 +1309,12 @@ void iomap_file_buffered_write_punch_delalloc(struct inode *inode,
}
EXPORT_SYMBOL_GPL(iomap_file_buffered_write_punch_delalloc);
-static loff_t iomap_unshare_iter(struct iomap_iter *iter)
+bool iomap_want_unshare_iter(const struct iomap_iter *iter)
{
- struct iomap *iomap = &iter->iomap;
- loff_t pos = iter->pos;
- loff_t length = iomap_length(iter);
- loff_t written = 0;
-
- /* Don't bother with blocks that are not shared to start with. */
- if (!(iomap->flags & IOMAP_F_SHARED))
- return length;
-
/*
- * Don't bother with delalloc reservations, holes or unwritten extents.
+ * Don't bother with blocks that are not shared to start with; or
+ * mappings that cannot be shared, such as inline data, delalloc
+ * reservations, holes or unwritten extents.
*
* Note that we use srcmap directly instead of iomap_iter_srcmap as
* unsharing requires providing a separate source map, and the presence
@@ -1329,9 +1322,18 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter)
* IOMAP_F_SHARED which can be set for any data that goes into the COW
* fork for XFS.
*/
- if (iter->srcmap.type == IOMAP_HOLE ||
- iter->srcmap.type == IOMAP_DELALLOC ||
- iter->srcmap.type == IOMAP_UNWRITTEN)
+ return (iter->iomap.flags & IOMAP_F_SHARED) &&
+ iter->srcmap.type == IOMAP_MAPPED;
+}
+
+static loff_t iomap_unshare_iter(struct iomap_iter *iter)
+{
+ struct iomap *iomap = &iter->iomap;
+ loff_t pos = iter->pos;
+ loff_t length = iomap_length(iter);
+ loff_t written = 0;
+
+ if (!iomap_want_unshare_iter(iter))
return length;
do {
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 1e11f48814c0..dc0443848485 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -707,7 +707,7 @@ imap_needs_cow(
return false;
/* when zeroing we don't have to COW holes or unwritten extents */
- if (flags & IOMAP_ZERO) {
+ if (flags & (IOMAP_UNSHARE | IOMAP_ZERO)) {
if (!nimaps ||
imap->br_startblock == HOLESTARTBLOCK ||
imap->br_state == XFS_EXT_UNWRITTEN)
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 4ad12a3c8bae..d8a7fc84348c 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -267,6 +267,7 @@ void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len);
bool iomap_dirty_folio(struct address_space *mapping, struct folio *folio);
int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
const struct iomap_ops *ops);
+bool iomap_want_unshare_iter(const struct iomap_iter *iter);
int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
bool *did_zero, const struct iomap_ops *ops);
int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,