From 6ff958edbf39c014eb06b65ad25b736be08c4e63 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 18 Oct 2007 03:07:02 -0700 Subject: [PATCH] fuse: add atomic open+truncate support This patch allows fuse filesystems to implement open(..., O_TRUNC) as a single request, instead of separate truncate and open requests. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dir.c | 3 +++ fs/fuse/file.c | 4 +++- fs/fuse/fuse_i.h | 3 +++ fs/fuse/inode.c | 5 ++++- include/linux/fuse.h | 1 + 5 files changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 537d38bee1..052327bd6c 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1083,6 +1083,9 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, return err; } + if ((attr->ia_valid & ATTR_OPEN) && fc->atomic_o_trunc) + return 0; + if (attr->ia_valid & ATTR_SIZE) { unsigned long limit; if (IS_SWAPFILE(inode)) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 4a28c3d377..6726378661 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -28,7 +28,9 @@ static int fuse_send_open(struct inode *inode, struct file *file, int isdir, return PTR_ERR(req); memset(&inarg, 0, sizeof(inarg)); - inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); + inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY); + if (!fc->atomic_o_trunc) + inarg.flags &= ~O_TRUNC; req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; req->in.h.nodeid = get_node_id(inode); req->in.numargs = 1; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index ffbcadaa7d..b24fc9b386 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -320,6 +320,9 @@ struct fuse_conn { /** Do readpages asynchronously? Only set in INIT */ unsigned async_read : 1; + /** Do not send separate SETATTR request before open(O_TRUNC) */ + unsigned atomic_o_trunc : 1; + /* * The following bitfields are only for optimization purposes * and hence races in setting them will not cause malfunction diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 6ef3973f40..3c13981f48 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -531,6 +531,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) fc->async_read = 1; if (!(arg->flags & FUSE_POSIX_LOCKS)) fc->no_lock = 1; + if (arg->flags & FUSE_ATOMIC_O_TRUNC) + fc->atomic_o_trunc = 1; } else { ra_pages = fc->max_read / PAGE_CACHE_SIZE; fc->no_lock = 1; @@ -553,7 +555,8 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) arg->major = FUSE_KERNEL_VERSION; arg->minor = FUSE_KERNEL_MINOR_VERSION; arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; - arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_FILE_OPS; + arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_FILE_OPS | + FUSE_ATOMIC_O_TRUNC; 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 43a77d7334..436047093b 100644 --- a/include/linux/fuse.h +++ b/include/linux/fuse.h @@ -101,6 +101,7 @@ struct fuse_file_lock { #define FUSE_ASYNC_READ (1 << 0) #define FUSE_POSIX_LOCKS (1 << 1) #define FUSE_FILE_OPS (1 << 2) +#define FUSE_ATOMIC_O_TRUNC (1 << 3) /** * Release flags -- 2.39.5