@@ -24,6 +24,7 @@
#include "block-group.h"
#include "backref.h"
#include "misc.h"
+#include "subpage.h"
/*
* Relocation overview
@@ -2886,6 +2887,17 @@ noinline int btrfs_should_cancel_balance(struct btrfs_fs_info *fs_info)
}
ALLOW_ERROR_INJECTION(btrfs_should_cancel_balance, TRUE);
+static u64 get_cluster_boundary_end(struct file_extent_cluster *cluster,
+ int cluster_nr)
+{
+ /* Last extent, use cluster end directly */
+ if (cluster_nr >= cluster->nr - 1)
+ return cluster->end;
+
+ /* Use next boundary start*/
+ return cluster->boundary[cluster_nr + 1] - 1;
+}
+
static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
struct file_extent_cluster *cluster,
int *cluster_nr, unsigned long page_index)
@@ -2897,22 +2909,17 @@ static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
struct page *page;
u64 page_start;
u64 page_end;
+ u64 cur;
int ret;
ASSERT(page_index <= last_index);
- ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), PAGE_SIZE);
- if (ret)
- return ret;
-
page = find_lock_page(inode->i_mapping, page_index);
if (!page) {
page_cache_sync_readahead(inode->i_mapping, ra, NULL,
page_index, last_index + 1 - page_index);
page = find_or_create_page(inode->i_mapping, page_index, mask);
- if (!page) {
- ret = -ENOMEM;
- goto release_delalloc;
- }
+ if (!page)
+ return -ENOMEM;
}
ret = set_page_extent_mapped(page);
if (ret < 0)
@@ -2934,30 +2941,76 @@ static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
page_start = page_offset(page);
page_end = page_start + PAGE_SIZE - 1;
- lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
-
- if (*cluster_nr < cluster->nr &&
- page_start + offset == cluster->boundary[*cluster_nr]) {
- set_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
- EXTENT_BOUNDARY);
- (*cluster_nr)++;
- }
+ /*
+ * Start from the cluster, as for subpage case, the cluster can start
+ * inside the page.
+ */
+ cur = max(page_start, cluster->boundary[*cluster_nr] - offset);
+ while (cur <= page_end) {
+ u64 extent_start = cluster->boundary[*cluster_nr] - offset;
+ u64 extent_end = get_cluster_boundary_end(cluster,
+ *cluster_nr) - offset;
+ u64 clamped_start = max(page_start, extent_start);
+ u64 clamped_end = min(page_end, extent_end);
+ u32 clamped_len = clamped_end + 1 - clamped_start;
+
+ /* Reserve metadata for this range */
+ ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
+ clamped_len);
+ if (ret)
+ goto release_page;
- ret = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, page_end,
- 0, NULL);
- if (ret) {
- clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start,
- page_end, EXTENT_LOCKED | EXTENT_BOUNDARY);
- goto release_page;
+ /* Mark the range delalloc and dirty for later writeback */
+ lock_extent(&BTRFS_I(inode)->io_tree, clamped_start,
+ clamped_end);
+ ret = btrfs_set_extent_delalloc(BTRFS_I(inode), clamped_start,
+ clamped_end, 0, NULL);
+ if (ret) {
+ clear_extent_bits(&BTRFS_I(inode)->io_tree,
+ clamped_start, clamped_end,
+ EXTENT_LOCKED | EXTENT_BOUNDARY);
+ btrfs_delalloc_release_metadata(BTRFS_I(inode),
+ clamped_len, true);
+ btrfs_delalloc_release_extents(BTRFS_I(inode),
+ clamped_len);
+ goto release_page;
+ }
+ btrfs_page_set_dirty(fs_info, page, clamped_start, clamped_len);
+ /*
+ * Set the boundary if it's inside the page.
+ * Data relocation requires the destination extents have the
+ * same size as the source.
+ * EXTENT_BOUNDARY bit prevent current extent from being merged
+ * with previous extent.
+ */
+ if (in_range(cluster->boundary[*cluster_nr] - offset,
+ page_start, PAGE_SIZE)) {
+ u64 boundary_start = cluster->boundary[*cluster_nr] -
+ offset;
+ u64 boundary_end = boundary_start +
+ fs_info->sectorsize - 1;
+
+ set_extent_bits(&BTRFS_I(inode)->io_tree,
+ boundary_start, boundary_end,
+ EXTENT_BOUNDARY);
+ }
+ unlock_extent(&BTRFS_I(inode)->io_tree, clamped_start,
+ clamped_end);
+ btrfs_delalloc_release_extents(BTRFS_I(inode), clamped_len);
+ cur += clamped_len;
+
+ /* Crossed extent end, go to next extent */
+ if (cur >= extent_end) {
+ (*cluster_nr)++;
+ /* Just finished the last extent of the cluster, exit. */
+ if (*cluster_nr >= cluster->nr)
+ break;
+ }
}
- set_page_dirty(page);
-
- unlock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
unlock_page(page);
put_page(page);
- btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
balance_dirty_pages_ratelimited(inode->i_mapping);
btrfs_throttle(fs_info);
if (btrfs_should_cancel_balance(fs_info))
@@ -2967,9 +3020,6 @@ static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
release_page:
unlock_page(page);
put_page(page);
-release_delalloc:
- btrfs_delalloc_release_metadata(BTRFS_I(inode), PAGE_SIZE, true);
- btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
return ret;
}
For subpage case, one page of data reloc inode can contain several file extents, like this: |<--- File extent A --->| FE B | FE C |<--- File extent D -->| |<--------- Page --------->| We can no longer use PAGE_SIZE directly for various operations. This patch will relocate_one_page() to handle subpage case by: - Iterating through all extents of a cluster when marking pages When marking pages dirty and delalloc, we need to check the cluster extent boundary. Now we introduce a loop to go extent by extent of a page, until we either finished the last extent, or reach the page end. By this, regular sectorsize == PAGE_SIZE can still work as usual, since we will do that loop only once. - Iteration start from max(page_start, extent_start) Since we can have the following case: | FE B | FE C |<--- File extent D -->| |<--------- Page --------->| Thus we can't always start from page_start, but do a max(page_start, extent_start) - Iteration end when the cluster is exhausted Similar to previous case, the last file extent can end before the page end: |<--- File extent A --->| FE B | FE C | |<--------- Page --------->| In this case, we need to manually exit the loop after we have finished the last extent of the cluster. - Reserve metadata space for each extent range Since now we can hit multiple ranges in one page, we should reserve metadata for each range, not simply PAGE_SIZE. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/relocation.c | 108 ++++++++++++++++++++++++++++++------------ 1 file changed, 79 insertions(+), 29 deletions(-)