From: Darrick J. Wong <djwong@xxxxxxxxxx>
When iomap is in use for the pagecache, it will take care of zeroing the
unaligned parts of punched out regions so we don't have to do it
ourselves.
Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
misc/fuse2fs.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index f7d17737459c11..45eec59d85faf4 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -235,6 +235,7 @@ enum fuse2fs_iomap_state {
IOMAP_DISABLED,
IOMAP_UNKNOWN,
IOMAP_ENABLED,
+ IOMAP_FILEIO, /* enabled and does all file data block IO */
};
#endif
@@ -494,8 +495,14 @@ static int fuse2fs_iomap_enabled(const struct fuse2fs *ff)
{
return ff->iomap_state >= IOMAP_ENABLED;
}
+
+static int fuse2fs_iomap_does_fileio(const struct fuse2fs *ff)
+{
+ return ff->iomap_state == IOMAP_FILEIO;
+}
#else
# define fuse2fs_iomap_enabled(...) (0)
+# define fuse2fs_iomap_does_fileio(...) (0)
#endif
static inline void fuse2fs_dump_extents(struct fuse2fs *ff, ext2_ino_t ino,
@@ -1219,6 +1226,7 @@ static void fuse2fs_iomap_confirm(struct fuse_conn_info *conn,
return;
case IOMAP_DISABLED:
return;
+ case IOMAP_FILEIO:
case IOMAP_ENABLED:
break;
}
@@ -1267,6 +1275,20 @@ static void *op_init(struct fuse_conn_info *conn
if (ff->iomap_state != IOMAP_DISABLED &&
fuse_set_feature_flag(conn, FUSE_CAP_IOMAP))
ff->iomap_state = IOMAP_ENABLED;
+
+ /*
+ * If iomap is turned on and the kernel advertises support for both
+ * direct and buffered IO, then that means the kernel handles all
+ * regular file data block IO for us. That means we can turn off all
+ * of libext2fs' file data block handling except for inline data.
+ *
+ * XXX: kernel doesn't support inline data iomap
+ */
+ if (fuse2fs_iomap_enabled(ff) &&
+ fuse_get_feature_flag(conn, FUSE_CAP_IOMAP_DIRECTIO) &&
+ fuse_get_feature_flag(conn, FUSE_CAP_IOMAP_FILEIO))
+ ff->iomap_state = IOMAP_FILEIO;
+
/*
* In iomap mode, the kernel writes file data directly to the block
* device and does not flush the bdev page cache. We must open the
@@ -4734,6 +4756,10 @@ static errcode_t clean_block_middle(struct fuse2fs *ff, ext2_ino_t ino,
int retflags;
errcode_t err;
+ /* the kernel does this for us in iomap mode */
+ if (fuse2fs_iomap_does_fileio(ff))
+ return 0;
+
if (!*buf) {
err = ext2fs_get_mem(fs->blocksize, buf);
if (err)
@@ -4767,6 +4793,10 @@ static errcode_t clean_block_edge(struct fuse2fs *ff, ext2_ino_t ino,
off_t residue;
errcode_t err;
+ /* the kernel does this for us in iomap mode */
+ if (fuse2fs_iomap_does_fileio(ff))
+ return 0;
+
residue = FUSE2FS_OFF_IN_FSB(ff, offset);
if (residue == 0)
return 0;
