Introduce a bit kernel and userspace exchange between each-other on the init stage and turn writeback on if the userspace want this and mount option 'allow_wbcache' is present (controlled by fusermount).
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. Original patch by: Pavel Emelyanov <[email protected]> Signed-off-by: Maxim Patlasov <[email protected]> --- fs/fuse/file.c | 15 +++++++++++++++ fs/fuse/fuse_i.h | 4 ++++ fs/fuse/inode.c | 13 +++++++++++++ include/uapi/linux/fuse.h | 2 ++ 4 files changed, 34 insertions(+), 0 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index e6e064c..147e618 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -211,6 +211,8 @@ 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) @@ -1096,6 +1098,19 @@ 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) { + if (!(file->f_flags & O_DIRECT)) { + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_inode *fi = get_fuse_inode(inode); + + spin_lock(&fc->lock); + inode->i_mtime = current_fs_time(inode->i_sb); + set_bit(FUSE_I_MTIME_UPDATED, &fi->state); + spin_unlock(&fc->lock); + } + return generic_file_aio_write(iocb, iov, nr_segs, pos); + } + WARN_ON(iocb->ki_pos != pos); ocount = 0; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 86caa8c..a207744 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -44,6 +44,10 @@ doing the mount will be allowed to access the filesystem */ #define FUSE_ALLOW_OTHER (1 << 1) +/** If the FUSE_ALLOW_WBCACHE flag is given, the filesystem + module will enable support of writback cache */ +#define FUSE_ALLOW_WBCACHE (1 << 2) + /** Number of page pointers embedded in fuse_req */ #define FUSE_REQ_INLINE_PAGES 1 diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 3687daf..541fc4f 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -521,6 +521,7 @@ enum { OPT_ALLOW_OTHER, OPT_MAX_READ, OPT_BLKSIZE, + OPT_ALLOW_WBCACHE, OPT_ERR }; @@ -533,6 +534,7 @@ static const match_table_t tokens = { {OPT_ALLOW_OTHER, "allow_other"}, {OPT_MAX_READ, "max_read=%u"}, {OPT_BLKSIZE, "blksize=%u"}, + {OPT_ALLOW_WBCACHE, "allow_wbcache"}, {OPT_ERR, NULL} }; @@ -606,6 +608,10 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev) d->blksize = value; break; + case OPT_ALLOW_WBCACHE: + d->flags |= FUSE_ALLOW_WBCACHE; + break; + default: return 0; } @@ -633,6 +639,8 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root) seq_printf(m, ",max_read=%u", fc->max_read); if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) seq_printf(m, ",blksize=%lu", sb->s_blocksize); + if (fc->flags & FUSE_ALLOW_WBCACHE) + seq_puts(m, ",allow_wbcache"); return 0; } @@ -944,6 +952,9 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) fc->auto_inval_data = 1; if (arg->flags & FUSE_DO_READDIRPLUS) fc->do_readdirplus = 1; + if (arg->flags & FUSE_WRITEBACK_CACHE && + fc->flags & FUSE_ALLOW_WBCACHE) + fc->writeback_cache = 1; } else { ra_pages = fc->max_read / PAGE_CACHE_SIZE; fc->no_lock = 1; @@ -972,6 +983,8 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | FUSE_DO_READDIRPLUS; + if (fc->flags & FUSE_ALLOW_WBCACHE) + arg->flags |= FUSE_WRITEBACK_CACHE; req->in.h.opcode = FUSE_INIT; req->in.numargs = 1; req->in.args[0].size = sizeof(*arg); diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 5dc1fea..20a9553 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -179,6 +179,7 @@ struct fuse_file_lock { * FUSE_FLOCK_LOCKS: remote locking for BSD style file locks * FUSE_HAS_IOCTL_DIR: kernel supports ioctl on directories * FUSE_AUTO_INVAL_DATA: automatically invalidate cached pages + * FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes */ #define FUSE_ASYNC_READ (1 << 0) #define FUSE_POSIX_LOCKS (1 << 1) @@ -194,6 +195,7 @@ struct fuse_file_lock { #define FUSE_HAS_IOCTL_DIR (1 << 11) #define FUSE_AUTO_INVAL_DATA (1 << 12) #define FUSE_DO_READDIRPLUS (1 << 13) +#define FUSE_WRITEBACK_CACHE (1 << 14) /** * CUSE INIT request/reply flags _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
