From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Add a new iomap_swapfile_activate function so that filesystems can
activate swap files without having to use the obsolete and slow bmap
function.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/iomap.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_aops.c | 12 ++++++
include/linux/iomap.h | 7 +++
3 files changed, 118 insertions(+)
diff --git a/fs/iomap.c b/fs/iomap.c
index afd1635..ace921b 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1089,3 +1089,102 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
return ret;
}
EXPORT_SYMBOL_GPL(iomap_dio_rw);
+
+/* Swapfile activation */
+
+struct iomap_swapfile_info {
+ struct swap_info_struct *sis;
+ uint64_t lowest_ppage; /* lowest physical addr seen (pages) */
+ uint64_t highest_ppage; /* highest physical addr seen (pages) */
+ unsigned long expected_page_no; /* next logical offset wanted (pages) */
+ int nr_extents; /* extent count */
+};
+
+static loff_t iomap_swapfile_activate_actor(struct inode *inode, loff_t pos,
+ loff_t count, void *data, struct iomap *iomap)
+{
+ struct iomap_swapfile_info *isi = data;
+ unsigned long page_no = iomap->offset >> PAGE_SHIFT;
+ unsigned long nr_pages = iomap->length >> PAGE_SHIFT;
+ uint64_t first_ppage = iomap->addr >> PAGE_SHIFT;
+ uint64_t last_ppage = ((iomap->addr + iomap->length) >> PAGE_SHIFT) - 1;
+
+ /* Only one bdev per swap file. */
+ if (iomap->bdev != isi->sis->bdev)
+ goto err;
+
+ /* Must be aligned to a page boundary. */
+ if ((iomap->offset & ~PAGE_MASK) || (iomap->addr & ~PAGE_MASK) ||
+ (iomap->length & ~PAGE_MASK))
+ goto err;
+
+ /* Only real or unwritten extents. */
+ if (iomap->type != IOMAP_MAPPED && iomap->type != IOMAP_UNWRITTEN)
+ goto err;
+
+ /* No sparse files. */
+ if (isi->expected_page_no != page_no)
+ goto err;
+
+ /* No uncommitted metadata or shared blocks or inline data. */
+ if (iomap->flags & (IOMAP_F_DIRTY | IOMAP_F_SHARED |
+ IOMAP_F_DATA_INLINE))
+ goto err;
+
+ /*
+ * Calculate how much swap space we're adding; the first page contains
+ * the swap header and doesn't count.
+ */
+ if (page_no == 0)
+ first_ppage++;
+ if (isi->lowest_ppage > first_ppage)
+ isi->lowest_ppage = first_ppage;
+ if (isi->highest_ppage < last_ppage)
+ isi->highest_ppage = last_ppage;
+
+ /* Add extent, set up for the next call. */
+ isi->nr_extents += add_swap_extent(isi->sis, page_no, nr_pages,
+ first_ppage);
+ isi->expected_page_no = page_no + nr_pages;
+
+ return count;
+err:
+ pr_err("swapon: swapfile has holes\n");
+ return -EINVAL;
+}
+
+int iomap_swapfile_activate(struct swap_info_struct *sis,
+ struct file *swap_file, sector_t *pagespan,
+ const struct iomap_ops *ops)
+{
+ struct iomap_swapfile_info isi = {
+ .sis = sis,
+ .lowest_ppage = (sector_t)-1ULL,
+ };
+ struct address_space *mapping = swap_file->f_mapping;
+ struct inode *inode = mapping->host;
+ loff_t pos = 0;
+ loff_t len = i_size_read(inode);
+ loff_t ret;
+
+ ret = filemap_write_and_wait(inode->i_mapping);
+ if (ret)
+ return ret;
+
+ while (len > 0) {
+ ret = iomap_apply(inode, pos, len, IOMAP_REPORT,
+ ops, &isi, iomap_swapfile_activate_actor);
+ if (ret <= 0)
+ return ret;
+
+ pos += ret;
+ len -= ret;
+ }
+
+ *pagespan = 1 + isi.highest_ppage - isi.lowest_ppage;
+ sis->max = isi.expected_page_no;
+ sis->pages = isi.expected_page_no - 1;
+ sis->highest_bit = isi.expected_page_no - 1;
+ return isi.nr_extents;
+}
+EXPORT_SYMBOL_GPL(iomap_swapfile_activate);
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 0ab824f..80de476 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1475,6 +1475,16 @@ xfs_vm_set_page_dirty(
return newly_dirty;
}
+static int
+xfs_iomap_swapfile_activate(
+ struct swap_info_struct *sis,
+ struct file *swap_file,
+ sector_t *span)
+{
+ sis->bdev = xfs_find_bdev_for_inode(file_inode(swap_file));
+ return iomap_swapfile_activate(sis, swap_file, span, &xfs_iomap_ops);
+}
+
const struct address_space_operations xfs_address_space_operations = {
.readpage = xfs_vm_readpage,
.readpages = xfs_vm_readpages,
@@ -1488,6 +1498,7 @@ const struct address_space_operations xfs_address_space_operations = {
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
+ .swap_activate = xfs_iomap_swapfile_activate,
};
const struct address_space_operations xfs_dax_aops = {
@@ -1495,4 +1506,5 @@ const struct address_space_operations xfs_dax_aops = {
.direct_IO = noop_direct_IO,
.set_page_dirty = noop_set_page_dirty,
.invalidatepage = noop_invalidatepage,
+ .swap_activate = xfs_iomap_swapfile_activate,
};
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 19a07de..66d1c35 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -106,4 +106,11 @@ typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops, iomap_dio_end_io_t end_io);
+struct file;
+struct swap_info_struct;
+
+int iomap_swapfile_activate(struct swap_info_struct *sis,
+ struct file *swap_file, sector_t *pagespan,
+ const struct iomap_ops *ops);
+
#endif /* LINUX_IOMAP_H */
