Commit 6ff958ed authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
Browse files

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: default avatarMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 17637cba
...@@ -1083,6 +1083,9 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, ...@@ -1083,6 +1083,9 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
return err; return err;
} }
if ((attr->ia_valid & ATTR_OPEN) && fc->atomic_o_trunc)
return 0;
if (attr->ia_valid & ATTR_SIZE) { if (attr->ia_valid & ATTR_SIZE) {
unsigned long limit; unsigned long limit;
if (IS_SWAPFILE(inode)) if (IS_SWAPFILE(inode))
......
...@@ -28,7 +28,9 @@ static int fuse_send_open(struct inode *inode, struct file *file, int isdir, ...@@ -28,7 +28,9 @@ static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
return PTR_ERR(req); return PTR_ERR(req);
memset(&inarg, 0, sizeof(inarg)); 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.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
req->in.h.nodeid = get_node_id(inode); req->in.h.nodeid = get_node_id(inode);
req->in.numargs = 1; req->in.numargs = 1;
......
...@@ -320,6 +320,9 @@ struct fuse_conn { ...@@ -320,6 +320,9 @@ struct fuse_conn {
/** Do readpages asynchronously? Only set in INIT */ /** Do readpages asynchronously? Only set in INIT */
unsigned async_read : 1; 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 * The following bitfields are only for optimization purposes
* and hence races in setting them will not cause malfunction * and hence races in setting them will not cause malfunction
......
...@@ -531,6 +531,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) ...@@ -531,6 +531,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
fc->async_read = 1; fc->async_read = 1;
if (!(arg->flags & FUSE_POSIX_LOCKS)) if (!(arg->flags & FUSE_POSIX_LOCKS))
fc->no_lock = 1; fc->no_lock = 1;
if (arg->flags & FUSE_ATOMIC_O_TRUNC)
fc->atomic_o_trunc = 1;
} else { } else {
ra_pages = fc->max_read / PAGE_CACHE_SIZE; ra_pages = fc->max_read / PAGE_CACHE_SIZE;
fc->no_lock = 1; fc->no_lock = 1;
...@@ -553,7 +555,8 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) ...@@ -553,7 +555,8 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
arg->major = FUSE_KERNEL_VERSION; arg->major = FUSE_KERNEL_VERSION;
arg->minor = FUSE_KERNEL_MINOR_VERSION; arg->minor = FUSE_KERNEL_MINOR_VERSION;
arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; 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.h.opcode = FUSE_INIT;
req->in.numargs = 1; req->in.numargs = 1;
req->in.args[0].size = sizeof(*arg); req->in.args[0].size = sizeof(*arg);
......
...@@ -101,6 +101,7 @@ struct fuse_file_lock { ...@@ -101,6 +101,7 @@ struct fuse_file_lock {
#define FUSE_ASYNC_READ (1 << 0) #define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1) #define FUSE_POSIX_LOCKS (1 << 1)
#define FUSE_FILE_OPS (1 << 2) #define FUSE_FILE_OPS (1 << 2)
#define FUSE_ATOMIC_O_TRUNC (1 << 3)
/** /**
* Release flags * Release flags
......
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