From fd72faac95d7e47610e981d7ed7b3c1529e55c88 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Mon, 7 Nov 2005 00:59:51 -0800 Subject: [PATCH] [PATCH] FUSE: atomic create+open This patch adds an atomic create+open operation. This does not yet work if the file type changes between lookup and create+open, but solves the permission checking problems for the separte create and open methods. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dev.c | 7 +++ fs/fuse/dir.c | 106 ++++++++++++++++++++++++++++++++++++++++- fs/fuse/file.c | 132 +++++++++++++++++++++++++++++++++------------------ fs/fuse/fuse_i.h | 14 ++++++ include/linux/fuse.h | 5 +- 5 files changed, 214 insertions(+), 50 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index a6f90a6..8f873e6 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -184,6 +184,13 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req) fuse_putback_request() */ for (i = 1; i < FUSE_MAX_OUTSTANDING; i++) up(&fc->outstanding_sem); + } else if (req->in.h.opcode == FUSE_RELEASE && req->inode == NULL) { + /* Special case for failed iget in CREATE */ + u64 nodeid = req->in.h.nodeid; + __fuse_get_request(req); + fuse_reset_request(req); + fuse_send_forget(fc, req, nodeid, 1); + putback = 0; } if (putback) fuse_putback_request(fc, req); diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 4bc1afc..83be119 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -13,6 +13,7 @@ #include #include #include +#include static inline unsigned long time_to_jiffies(unsigned long sec, unsigned long nsec) @@ -134,6 +135,101 @@ static void fuse_invalidate_entry(struct dentry *entry) entry->d_time = jiffies - 1; } +static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, + struct nameidata *nd) +{ + int err; + struct inode *inode; + struct fuse_conn *fc = get_fuse_conn(dir); + struct fuse_req *req; + struct fuse_open_in inarg; + struct fuse_open_out outopen; + struct fuse_entry_out outentry; + struct fuse_inode *fi; + struct fuse_file *ff; + struct file *file; + int flags = nd->intent.open.flags - 1; + + err = -ENOSYS; + if (fc->no_create) + goto out; + + err = -ENAMETOOLONG; + if (entry->d_name.len > FUSE_NAME_MAX) + goto out; + + err = -EINTR; + req = fuse_get_request(fc); + if (!req) + goto out; + + ff = fuse_file_alloc(); + if (!ff) + goto out_put_request; + + flags &= ~O_NOCTTY; + memset(&inarg, 0, sizeof(inarg)); + inarg.flags = flags; + inarg.mode = mode; + req->in.h.opcode = FUSE_CREATE; + req->in.h.nodeid = get_node_id(dir); + req->inode = dir; + req->in.numargs = 2; + req->in.args[0].size = sizeof(inarg); + req->in.args[0].value = &inarg; + req->in.args[1].size = entry->d_name.len + 1; + req->in.args[1].value = entry->d_name.name; + req->out.numargs = 2; + req->out.args[0].size = sizeof(outentry); + req->out.args[0].value = &outentry; + req->out.args[1].size = sizeof(outopen); + req->out.args[1].value = &outopen; + request_send(fc, req); + err = req->out.h.error; + if (err) { + if (err == -ENOSYS) + fc->no_create = 1; + goto out_free_ff; + } + + err = -EIO; + if (!S_ISREG(outentry.attr.mode)) + goto out_free_ff; + + inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, + &outentry.attr); + err = -ENOMEM; + if (!inode) { + flags &= ~(O_CREAT | O_EXCL | O_TRUNC); + ff->fh = outopen.fh; + fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0); + goto out_put_request; + } + fuse_put_request(fc, req); + entry->d_time = time_to_jiffies(outentry.entry_valid, + outentry.entry_valid_nsec); + fi = get_fuse_inode(inode); + fi->i_time = time_to_jiffies(outentry.attr_valid, + outentry.attr_valid_nsec); + + d_instantiate(entry, inode); + file = lookup_instantiate_filp(nd, entry, generic_file_open); + if (IS_ERR(file)) { + ff->fh = outopen.fh; + fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0); + return PTR_ERR(file); + } + fuse_finish_open(inode, file, ff, &outopen); + return 0; + + out_free_ff: + fuse_file_free(ff); + out_put_request: + fuse_put_request(fc, req); + out: + return err; +} + static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, struct inode *dir, struct dentry *entry, int mode) @@ -208,6 +304,12 @@ static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode, static int fuse_create(struct inode *dir, struct dentry *entry, int mode, struct nameidata *nd) { + if (nd && (nd->flags & LOOKUP_CREATE)) { + int err = fuse_create_open(dir, entry, mode, nd); + if (err != -ENOSYS) + return err; + /* Fall back on mknod */ + } return fuse_mknod(dir, entry, mode, 0); } @@ -767,7 +869,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, struct nameidata *nd) { struct inode *inode; - int err = fuse_lookup_iget(dir, entry, &inode); + int err; + + err = fuse_lookup_iget(dir, entry, &inode); if (err) return ERR_PTR(err); if (inode && S_ISDIR(inode->i_mode)) { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 657ab11..2ca8614 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -14,11 +14,69 @@ static struct file_operations fuse_direct_io_file_operations; -int fuse_open_common(struct inode *inode, struct file *file, int isdir) +static int fuse_send_open(struct inode *inode, struct file *file, int isdir, + struct fuse_open_out *outargp) { struct fuse_conn *fc = get_fuse_conn(inode); - struct fuse_req *req; struct fuse_open_in inarg; + struct fuse_req *req; + int err; + + req = fuse_get_request(fc); + if (!req) + return -EINTR; + + memset(&inarg, 0, sizeof(inarg)); + inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); + req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; + req->in.h.nodeid = get_node_id(inode); + req->inode = inode; + req->in.numargs = 1; + req->in.args[0].size = sizeof(inarg); + req->in.args[0].value = &inarg; + req->out.numargs = 1; + req->out.args[0].size = sizeof(*outargp); + req->out.args[0].value = outargp; + request_send(fc, req); + err = req->out.h.error; + fuse_put_request(fc, req); + + return err; +} + +struct fuse_file *fuse_file_alloc(void) +{ + struct fuse_file *ff; + ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); + if (ff) { + ff->release_req = fuse_request_alloc(); + if (!ff->release_req) { + kfree(ff); + ff = NULL; + } + } + return ff; +} + +void fuse_file_free(struct fuse_file *ff) +{ + fuse_request_free(ff->release_req); + kfree(ff); +} + +void fuse_finish_open(struct inode *inode, struct file *file, + struct fuse_file *ff, struct fuse_open_out *outarg) +{ + if (outarg->open_flags & FOPEN_DIRECT_IO) + file->f_op = &fuse_direct_io_file_operations; + if (!(outarg->open_flags & FOPEN_KEEP_CACHE)) + invalidate_inode_pages(inode->i_mapping); + ff->fh = outarg->fh; + file->private_data = ff; +} + +int fuse_open_common(struct inode *inode, struct file *file, int isdir) +{ struct fuse_open_out outarg; struct fuse_file *ff; int err; @@ -34,73 +92,53 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir) /* If opening the root node, no lookup has been performed on it, so the attributes must be refreshed */ if (get_node_id(inode) == FUSE_ROOT_ID) { - int err = fuse_do_getattr(inode); + err = fuse_do_getattr(inode); if (err) return err; } - req = fuse_get_request(fc); - if (!req) - return -EINTR; - - err = -ENOMEM; - ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); + ff = fuse_file_alloc(); if (!ff) - goto out_put_request; + return -ENOMEM; - ff->release_req = fuse_request_alloc(); - if (!ff->release_req) { - kfree(ff); - goto out_put_request; - } - - memset(&inarg, 0, sizeof(inarg)); - inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); - req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; - req->in.h.nodeid = get_node_id(inode); - req->inode = inode; - req->in.numargs = 1; - req->in.args[0].size = sizeof(inarg); - req->in.args[0].value = &inarg; - req->out.numargs = 1; - req->out.args[0].size = sizeof(outarg); - req->out.args[0].value = &outarg; - request_send(fc, req); - err = req->out.h.error; - if (err) { - fuse_request_free(ff->release_req); - kfree(ff); - } else { - if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO)) - file->f_op = &fuse_direct_io_file_operations; - if (!(outarg.open_flags & FOPEN_KEEP_CACHE)) - invalidate_inode_pages(inode->i_mapping); - ff->fh = outarg.fh; - file->private_data = ff; + err = fuse_send_open(inode, file, isdir, &outarg); + if (err) + fuse_file_free(ff); + else { + if (isdir) + outarg.open_flags &= ~FOPEN_DIRECT_IO; + fuse_finish_open(inode, file, ff, &outarg); } - out_put_request: - fuse_put_request(fc, req); return err; } -int fuse_release_common(struct inode *inode, struct file *file, int isdir) +void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff, + u64 nodeid, struct inode *inode, int flags, int isdir) { - struct fuse_conn *fc = get_fuse_conn(inode); - struct fuse_file *ff = file->private_data; - struct fuse_req *req = ff->release_req; + struct fuse_req * req = ff->release_req; struct fuse_release_in *inarg = &req->misc.release_in; inarg->fh = ff->fh; - inarg->flags = file->f_flags & ~O_EXCL; + inarg->flags = flags; req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE; - req->in.h.nodeid = get_node_id(inode); + req->in.h.nodeid = nodeid; req->inode = inode; req->in.numargs = 1; req->in.args[0].size = sizeof(struct fuse_release_in); req->in.args[0].value = inarg; request_send_background(fc, req); kfree(ff); +} + +int fuse_release_common(struct inode *inode, struct file *file, int isdir) +{ + struct fuse_file *ff = file->private_data; + if (ff) { + struct fuse_conn *fc = get_fuse_conn(inode); + u64 nodeid = get_node_id(inode); + fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir); + } /* Return value is ignored by VFS */ return 0; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index c4e8c3b..0ea5301 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -269,6 +269,9 @@ struct fuse_conn { /** Is access not implemented by fs? */ unsigned no_access : 1; + /** Is create not implemented by fs? */ + unsigned no_create : 1; + /** Backing dev info */ struct backing_dev_info bdi; }; @@ -340,6 +343,17 @@ size_t fuse_send_read_common(struct fuse_req *req, struct file *file, */ int fuse_open_common(struct inode *inode, struct file *file, int isdir); +struct fuse_file *fuse_file_alloc(void); +void fuse_file_free(struct fuse_file *ff); +void fuse_finish_open(struct inode *inode, struct file *file, + struct fuse_file *ff, struct fuse_open_out *outarg); + +/** + * Send a RELEASE request + */ +void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff, + u64 nodeid, struct inode *inode, int flags, int isdir); + /** * Send RELEASE or RELEASEDIR request */ diff --git a/include/linux/fuse.h b/include/linux/fuse.h index 507913b..45c398f 100644 --- a/include/linux/fuse.h +++ b/include/linux/fuse.h @@ -100,7 +100,8 @@ enum fuse_opcode { FUSE_READDIR = 28, FUSE_RELEASEDIR = 29, FUSE_FSYNCDIR = 30, - FUSE_ACCESS = 34 + FUSE_ACCESS = 34, + FUSE_CREATE = 35 }; /* Conservative buffer size for the client */ @@ -158,7 +159,7 @@ struct fuse_setattr_in { struct fuse_open_in { __u32 flags; - __u32 padding; + __u32 mode; }; struct fuse_open_out { -- 1.8.2.3