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Re: [PATCH v2] virtiofsd/passthrough_ll: don't remove O_DIRECT when cach
From: |
Catherine Ho |
Subject: |
Re: [PATCH v2] virtiofsd/passthrough_ll: don't remove O_DIRECT when cache=none |
Date: |
Tue, 21 Apr 2020 09:55:45 +0800 |
Ping :)
---
B.R.
Catherine
On Sat, 11 Apr 2020 at 16:41, Catherine Ho <address@hidden> wrote:
>
> cache=none means to bypass host cache. So we can't remove O_DIRECT flag in
> unconditionally in update_open_flags();
>
> Signed-off-by: Catherine Ho <address@hidden>
> ---
> v2: Fix to keep flags unchanged if cache=none, otherwise changed the file
> without O_DIRECT incorrectly.
> tools/virtiofsd/passthrough_ll.c | 14 ++++++++------
> 1 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/tools/virtiofsd/passthrough_ll.c
> b/tools/virtiofsd/passthrough_ll.c
> index 4c35c95..59e64dd 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -1677,7 +1677,8 @@ static void lo_releasedir(fuse_req_t req, fuse_ino_t
> ino,
> fuse_reply_err(req, 0);
> }
>
> -static void update_open_flags(int writeback, struct fuse_file_info *fi)
> +static void update_open_flags(int writeback, int cache_mode,
> + struct fuse_file_info *fi)
> {
> /*
> * With writeback cache, kernel may send read requests even
> @@ -1702,10 +1703,11 @@ static void update_open_flags(int writeback, struct
> fuse_file_info *fi)
>
> /*
> * O_DIRECT in guest should not necessarily mean bypassing page
> - * cache on host as well. If somebody needs that behavior, it
> - * probably should be a configuration knob in daemon.
> + * cache on host as well. If cache=none, keep the flag unchanged
> */
> - fi->flags &= ~O_DIRECT;
> + if (cache_mode != CACHE_NONE) {
> + fi->flags &= ~O_DIRECT;
> + }
> }
>
> static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
> @@ -1737,7 +1739,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t
> parent, const char *name,
> goto out;
> }
>
> - update_open_flags(lo->writeback, fi);
> + update_open_flags(lo->writeback, lo->cache, fi);
>
> fd = openat(parent_inode->fd, name, (fi->flags | O_CREAT) & ~O_NOFOLLOW,
> mode);
> @@ -1947,7 +1949,7 @@ static void lo_open(fuse_req_t req, fuse_ino_t ino,
> struct fuse_file_info *fi)
> fuse_log(FUSE_LOG_DEBUG, "lo_open(ino=%" PRIu64 ", flags=%d)\n", ino,
> fi->flags);
>
> - update_open_flags(lo->writeback, fi);
> + update_open_flags(lo->writeback, lo->cache, fi);
>
> sprintf(buf, "%i", lo_fd(req, ino));
> fd = openat(lo->proc_self_fd, buf, fi->flags & ~O_NOFOLLOW);
> --
> 1.7.1
>