From: Zhang Yi <yi.zhang@xxxxxxxxxx>
Introduce a new iomap address space operations ext4_iomap_aops to
support regular file's buffered IO path, also add an inode state flag
EXT4_STATE_BUFFERED_IOMAP, if it was set on an inode, it means that
inode use the iomap path instead of buffer_head path for buffered IO.
Most of their callbacks can use generic implementations, the left over
read_folio, readahead and writepages will be implemented later.
Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
fs/ext4/ext4.h | 1 +
fs/ext4/inode.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 7e27e1e7c579..05949a8136ae 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1913,6 +1913,7 @@ enum {
EXT4_STATE_VERITY_IN_PROGRESS, /* building fs-verity Merkle tree */
EXT4_STATE_FC_COMMITTING, /* Fast commit ongoing */
EXT4_STATE_ORPHAN_FILE, /* Inode orphaned in orphan file */
+ EXT4_STATE_BUFFERED_IOMAP, /* Inode use iomap for buffered IO */
};
#define EXT4_INODE_BIT_FNS(name, field, offset) \
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2704dca96ee7..4c1fed516d9e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3523,6 +3523,22 @@ const struct iomap_ops ext4_iomap_report_ops = {
.iomap_begin = ext4_iomap_begin_report,
};
+static int ext4_iomap_read_folio(struct file *file, struct folio *folio)
+{
+ return 0;
+}
+
+static void ext4_iomap_readahead(struct readahead_control *rac)
+{
+
+}
+
+static int ext4_iomap_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ return 0;
+}
+
/*
* For data=journal mode, folio should be marked dirty only when it was
* writeably mapped. When that happens, it was already attached to the
@@ -3612,6 +3628,21 @@ static const struct address_space_operations ext4_da_aops = {
.swap_activate = ext4_iomap_swap_activate,
};
+static const struct address_space_operations ext4_iomap_aops = {
+ .read_folio = ext4_iomap_read_folio,
+ .readahead = ext4_iomap_readahead,
+ .writepages = ext4_iomap_writepages,
+ .dirty_folio = iomap_dirty_folio,
+ .bmap = ext4_bmap,
+ .invalidate_folio = iomap_invalidate_folio,
+ .release_folio = iomap_release_folio,
+ .direct_IO = noop_direct_IO,
+ .migrate_folio = filemap_migrate_folio,
+ .is_partially_uptodate = iomap_is_partially_uptodate,
+ .error_remove_folio = generic_error_remove_folio,
+ .swap_activate = ext4_iomap_swap_activate,
+};
+
static const struct address_space_operations ext4_dax_aops = {
.writepages = ext4_dax_writepages,
.direct_IO = noop_direct_IO,
@@ -3634,6 +3665,8 @@ void ext4_set_aops(struct inode *inode)
}
if (IS_DAX(inode))
inode->i_mapping->a_ops = &ext4_dax_aops;
+ else if (ext4_test_inode_state(inode, EXT4_STATE_BUFFERED_IOMAP))
+ inode->i_mapping->a_ops = &ext4_iomap_aops;
else if (test_opt(inode->i_sb, DELALLOC))
inode->i_mapping->a_ops = &ext4_da_aops;
else
--
2.39.2
