Introduce a bit kernel and userspace exchange between each-other on
the init stage and turn writeback on if the userspace want this.
Also add each writable file into per-inode write list and call the
generic_file_aio_write to make use of the Linux page cache engine.
Signed-off-by: Pavel Emelyanov <redacted>
---
fs/fuse/file.c | 5 +++++
fs/fuse/inode.c | 4 +++-
include/linux/fuse.h | 1 +
3 files changed, 9 insertions(+), 1 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 058498d..e3a1cc8 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -209,6 +209,8 @@ void fuse_finish_open(struct inode *inode, struct file *file)
spin_unlock(&fc->lock);
fuse_invalidate_attr(inode);
}
+ if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
+ fuse_link_write_file(file);
}
int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
@@ -999,6 +1001,9 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
struct iov_iter i;
loff_t endbyte = 0;
+ if (get_fuse_conn(inode)->writeback_cache)
+ return generic_file_aio_write(iocb, iov, nr_segs, pos);
+
WARN_ON(iocb->ki_pos != pos);
ocount = 0;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 88c577f..df1dc83 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -836,6 +836,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
fc->big_writes = 1;
if (arg->flags & FUSE_DONT_MASK)
fc->dont_mask = 1;
+ if (arg->flags & FUSE_WRITEBACK_CACHE)
+ fc->writeback_cache = 1;
} else {
ra_pages = fc->max_read / PAGE_CACHE_SIZE;
fc->no_lock = 1;@@ -861,7 +863,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
- FUSE_FLOCK_LOCKS;
+ FUSE_FLOCK_LOCKS | FUSE_WRITEBACK_CACHE;
req->in.h.opcode = FUSE_INIT;
req->in.numargs = 1;
req->in.args[0].size = sizeof(*arg);
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 9303348..7ed5ced 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -176,6 +176,7 @@ struct fuse_file_lock {
#define FUSE_BIG_WRITES (1 << 5)
#define FUSE_DONT_MASK (1 << 6)
#define FUSE_FLOCK_LOCKS (1 << 10)
+#define FUSE_WRITEBACK_CACHE (1 << 11)
/**
* CUSE INIT request/reply flags--
1.5.5.6
------------------------------------------------------------------------------
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