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-rw-r--r--fs/xfs/xfs_aops.c50
-rw-r--r--fs/xfs/xfs_aops.h2
-rw-r--r--fs/xfs/xfs_file.c6
3 files changed, 49 insertions, 9 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 50ab2879b9da..e747d6ad5d18 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1250,13 +1250,28 @@ xfs_vm_releasepage(
* the DIO. There is only going to be one reference to the ioend and its life
* cycle is constrained by the DIO completion code. hence we don't need
* reference counting here.
+ *
+ * Note that for DIO, an IO to the highest supported file block offset (i.e.
+ * 2^63 - 1FSB bytes) will result in the offset + count overflowing a signed 64
+ * bit variable. Hence if we see this overflow, we have to assume that the IO is
+ * extending the file size. We won't know for sure until IO completion is run
+ * and the actual max write offset is communicated to the IO completion
+ * routine.
+ *
+ * For DAX page faults, we are preparing to never see unwritten extents here,
+ * nor should we ever extend the inode size. Hence we will soon have nothing to
+ * do here for this case, ensuring we don't have to provide an IO completion
+ * callback to free an ioend that we don't actually need for a fault into the
+ * page at offset (2^63 - 1FSB) bytes.
*/
+
static void
xfs_map_direct(
struct inode *inode,
struct buffer_head *bh_result,
struct xfs_bmbt_irec *imap,
- xfs_off_t offset)
+ xfs_off_t offset,
+ bool dax_fault)
{
struct xfs_ioend *ioend;
xfs_off_t size = bh_result->b_size;
@@ -1269,6 +1284,16 @@ xfs_map_direct(
trace_xfs_gbmap_direct(XFS_I(inode), offset, size, type, imap);
+ /* XXX: preparation for removing unwritten extents in DAX */
+#if 0
+ if (dax_fault) {
+ ASSERT(type == XFS_IO_OVERWRITE);
+ trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type,
+ imap);
+ return;
+ }
+#endif
+
if (bh_result->b_private) {
ioend = bh_result->b_private;
ASSERT(ioend->io_size > 0);
@@ -1283,7 +1308,8 @@ xfs_map_direct(
ioend->io_size, ioend->io_type,
imap);
} else if (type == XFS_IO_UNWRITTEN ||
- offset + size > i_size_read(inode)) {
+ offset + size > i_size_read(inode) ||
+ offset + size < 0) {
ioend = xfs_alloc_ioend(inode, type);
ioend->io_offset = offset;
ioend->io_size = size;
@@ -1345,7 +1371,8 @@ __xfs_get_blocks(
sector_t iblock,
struct buffer_head *bh_result,
int create,
- bool direct)
+ bool direct,
+ bool dax_fault)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
@@ -1458,7 +1485,8 @@ __xfs_get_blocks(
set_buffer_unwritten(bh_result);
/* direct IO needs special help */
if (create && direct)
- xfs_map_direct(inode, bh_result, &imap, offset);
+ xfs_map_direct(inode, bh_result, &imap, offset,
+ dax_fault);
}
/*
@@ -1505,7 +1533,7 @@ xfs_get_blocks(
struct buffer_head *bh_result,
int create)
{
- return __xfs_get_blocks(inode, iblock, bh_result, create, false);
+ return __xfs_get_blocks(inode, iblock, bh_result, create, false, false);
}
int
@@ -1515,7 +1543,17 @@ xfs_get_blocks_direct(
struct buffer_head *bh_result,
int create)
{
- return __xfs_get_blocks(inode, iblock, bh_result, create, true);
+ return __xfs_get_blocks(inode, iblock, bh_result, create, true, false);
+}
+
+int
+xfs_get_blocks_dax_fault(
+ struct inode *inode,
+ sector_t iblock,
+ struct buffer_head *bh_result,
+ int create)
+{
+ return __xfs_get_blocks(inode, iblock, bh_result, create, true, true);
}
static void
diff --git a/fs/xfs/xfs_aops.h b/fs/xfs/xfs_aops.h
index 86afd1ac7895..d39ba25ccc98 100644
--- a/fs/xfs/xfs_aops.h
+++ b/fs/xfs/xfs_aops.h
@@ -58,6 +58,8 @@ int xfs_get_blocks(struct inode *inode, sector_t offset,
struct buffer_head *map_bh, int create);
int xfs_get_blocks_direct(struct inode *inode, sector_t offset,
struct buffer_head *map_bh, int create);
+int xfs_get_blocks_dax_fault(struct inode *inode, sector_t offset,
+ struct buffer_head *map_bh, int create);
void xfs_end_io_dax_write(struct buffer_head *bh, int uptodate);
extern void xfs_count_page_state(struct page *, int *, int *);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index e78feb400e22..27abe1c92184 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1503,7 +1503,7 @@ xfs_filemap_page_mkwrite(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_direct,
+ ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault,
xfs_end_io_dax_write);
} else {
ret = __block_page_mkwrite(vma, vmf, xfs_get_blocks);
@@ -1538,7 +1538,7 @@ xfs_filemap_fault(
* changes to xfs_get_blocks_direct() to map unwritten extent
* ioend for conversion on read-only mappings.
*/
- ret = __dax_fault(vma, vmf, xfs_get_blocks_direct, NULL);
+ ret = __dax_fault(vma, vmf, xfs_get_blocks_dax_fault, NULL);
} else
ret = filemap_fault(vma, vmf);
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
@@ -1565,7 +1565,7 @@ xfs_filemap_pmd_fault(
sb_start_pagefault(inode->i_sb);
file_update_time(vma->vm_file);
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_direct,
+ ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault,
xfs_end_io_dax_write);
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
sb_end_pagefault(inode->i_sb);