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Diffstat (limited to 'fs/btrfs/extent_io.c')
-rw-r--r--fs/btrfs/extent_io.c75
1 files changed, 55 insertions, 20 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 835b0deef9bb..b21cb72835cc 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -111,6 +111,24 @@ struct btrfs_bio_ctrl {
*/
unsigned long submit_bitmap;
struct readahead_control *ractl;
+
+ /*
+ * The start offset of the last used extent map by a read operation.
+ *
+ * This is for proper compressed read merge.
+ * U64_MAX means we are starting the read and have made no progress yet.
+ *
+ * The current btrfs_bio_is_contig() only uses disk_bytenr as
+ * the condition to check if the read can be merged with previous
+ * bio, which is not correct. E.g. two file extents pointing to the
+ * same extent but with different offset.
+ *
+ * So here we need to do extra checks to only merge reads that are
+ * covered by the same extent map.
+ * Just extent_map::start will be enough, as they are unique
+ * inside the same inode.
+ */
+ u64 last_em_start;
};
static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
@@ -909,7 +927,7 @@ static void btrfs_readahead_expand(struct readahead_control *ractl,
* return 0 on success, otherwise return error
*/
static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
- struct btrfs_bio_ctrl *bio_ctrl, u64 *prev_em_start)
+ struct btrfs_bio_ctrl *bio_ctrl)
{
struct inode *inode = folio->mapping->host;
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
@@ -1019,12 +1037,11 @@ static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
* non-optimal behavior (submitting 2 bios for the same extent).
*/
if (compress_type != BTRFS_COMPRESS_NONE &&
- prev_em_start && *prev_em_start != (u64)-1 &&
- *prev_em_start != em->start)
+ bio_ctrl->last_em_start != U64_MAX &&
+ bio_ctrl->last_em_start != em->start)
force_bio_submit = true;
- if (prev_em_start)
- *prev_em_start = em->start;
+ bio_ctrl->last_em_start = em->start;
btrfs_free_extent_map(em);
em = NULL;
@@ -1238,12 +1255,15 @@ int btrfs_read_folio(struct file *file, struct folio *folio)
const u64 start = folio_pos(folio);
const u64 end = start + folio_size(folio) - 1;
struct extent_state *cached_state = NULL;
- struct btrfs_bio_ctrl bio_ctrl = { .opf = REQ_OP_READ };
+ struct btrfs_bio_ctrl bio_ctrl = {
+ .opf = REQ_OP_READ,
+ .last_em_start = U64_MAX,
+ };
struct extent_map *em_cached = NULL;
int ret;
lock_extents_for_read(inode, start, end, &cached_state);
- ret = btrfs_do_readpage(folio, &em_cached, &bio_ctrl, NULL);
+ ret = btrfs_do_readpage(folio, &em_cached, &bio_ctrl);
btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state);
btrfs_free_extent_map(em_cached);
@@ -1512,7 +1532,7 @@ out:
/*
* Return 0 if we have submitted or queued the sector for submission.
- * Return <0 for critical errors.
+ * Return <0 for critical errors, and the sector will have its dirty flag cleared.
*
* Caller should make sure filepos < i_size and handle filepos >= i_size case.
*/
@@ -1535,8 +1555,17 @@ static int submit_one_sector(struct btrfs_inode *inode,
ASSERT(filepos < i_size);
em = btrfs_get_extent(inode, NULL, filepos, sectorsize);
- if (IS_ERR(em))
+ if (IS_ERR(em)) {
+ /*
+ * When submission failed, we should still clear the folio dirty.
+ * Or the folio will be written back again but without any
+ * ordered extent.
+ */
+ btrfs_folio_clear_dirty(fs_info, folio, filepos, sectorsize);
+ btrfs_folio_set_writeback(fs_info, folio, filepos, sectorsize);
+ btrfs_folio_clear_writeback(fs_info, folio, filepos, sectorsize);
return PTR_ERR(em);
+ }
extent_offset = filepos - em->start;
em_end = btrfs_extent_map_end(em);
@@ -1609,8 +1638,12 @@ static noinline_for_stack int extent_writepage_io(struct btrfs_inode *inode,
folio_unlock(folio);
return 1;
}
- if (ret < 0)
+ if (ret < 0) {
+ btrfs_folio_clear_dirty(fs_info, folio, start, len);
+ btrfs_folio_set_writeback(fs_info, folio, start, len);
+ btrfs_folio_clear_writeback(fs_info, folio, start, len);
return ret;
+ }
for (cur = start; cur < start + len; cur += fs_info->sectorsize)
set_bit((cur - folio_start) >> fs_info->sectorsize_bits, &range_bitmap);
@@ -1666,8 +1699,8 @@ static noinline_for_stack int extent_writepage_io(struct btrfs_inode *inode,
* Here we set writeback and clear for the range. If the full folio
* is no longer dirty then we clear the PAGECACHE_TAG_DIRTY tag.
*
- * If we hit any error, the corresponding sector will still be dirty
- * thus no need to clear PAGECACHE_TAG_DIRTY.
+ * If we hit any error, the corresponding sector will have its dirty
+ * flag cleared and writeback finished, thus no need to handle the error case.
*/
if (!submitted_io && !error) {
btrfs_folio_set_writeback(fs_info, folio, start, len);
@@ -1813,6 +1846,7 @@ static noinline_for_stack bool lock_extent_buffer_for_io(struct extent_buffer *e
xas_load(&xas);
xas_set_mark(&xas, PAGECACHE_TAG_WRITEBACK);
xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY);
+ xas_clear_mark(&xas, PAGECACHE_TAG_TOWRITE);
xas_unlock_irqrestore(&xas, flags);
btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
@@ -2569,7 +2603,8 @@ void btrfs_readahead(struct readahead_control *rac)
{
struct btrfs_bio_ctrl bio_ctrl = {
.opf = REQ_OP_READ | REQ_RAHEAD,
- .ractl = rac
+ .ractl = rac,
+ .last_em_start = U64_MAX,
};
struct folio *folio;
struct btrfs_inode *inode = BTRFS_I(rac->mapping->host);
@@ -2577,12 +2612,11 @@ void btrfs_readahead(struct readahead_control *rac)
const u64 end = start + readahead_length(rac) - 1;
struct extent_state *cached_state = NULL;
struct extent_map *em_cached = NULL;
- u64 prev_em_start = (u64)-1;
lock_extents_for_read(inode, start, end, &cached_state);
while ((folio = readahead_folio(rac)) != NULL)
- btrfs_do_readpage(folio, &em_cached, &bio_ctrl, &prev_em_start);
+ btrfs_do_readpage(folio, &em_cached, &bio_ctrl);
btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state);
@@ -4331,15 +4365,18 @@ static int try_release_subpage_extent_buffer(struct folio *folio)
unsigned long end = index + (PAGE_SIZE >> fs_info->nodesize_bits) - 1;
int ret;
- xa_lock_irq(&fs_info->buffer_tree);
+ rcu_read_lock();
xa_for_each_range(&fs_info->buffer_tree, index, eb, start, end) {
/*
* The same as try_release_extent_buffer(), to ensure the eb
* won't disappear out from under us.
*/
spin_lock(&eb->refs_lock);
+ rcu_read_unlock();
+
if (refcount_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
spin_unlock(&eb->refs_lock);
+ rcu_read_lock();
continue;
}
@@ -4358,11 +4395,10 @@ static int try_release_subpage_extent_buffer(struct folio *folio)
* check the folio private at the end. And
* release_extent_buffer() will release the refs_lock.
*/
- xa_unlock_irq(&fs_info->buffer_tree);
release_extent_buffer(eb);
- xa_lock_irq(&fs_info->buffer_tree);
+ rcu_read_lock();
}
- xa_unlock_irq(&fs_info->buffer_tree);
+ rcu_read_unlock();
/*
* Finally to check if we have cleared folio private, as if we have
@@ -4375,7 +4411,6 @@ static int try_release_subpage_extent_buffer(struct folio *folio)
ret = 0;
spin_unlock(&folio->mapping->i_private_lock);
return ret;
-
}
int try_release_extent_buffer(struct folio *folio)
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-13 08:31:32 +0000