From c756e0a4d79202535774806f148026e40466a5eb Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 16 Oct 2007 23:31:00 -0700 Subject: fuse: add reference counting to fuse_file Make lifetime of 'struct fuse_file' independent from 'struct file' by adding a reference counter and destructor. This will enable asynchronous page writeback, where it cannot be guaranteed, that the file is not released while a request with this file handle is being served. The actual RELEASE request is only sent when there are no more references to the fuse_file. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dev.c | 2 -- fs/fuse/dir.c | 14 +++++------ fs/fuse/file.c | 72 ++++++++++++++++++++++++++++++++++---------------------- fs/fuse/fuse_i.h | 13 ++++++---- 4 files changed, 59 insertions(+), 42 deletions(-) (limited to 'fs/fuse') diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 9c9e35e42bfd..de25bff31420 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -233,8 +233,6 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req) spin_unlock(&fc->lock); dput(req->dentry); mntput(req->vfsmount); - if (req->file) - fput(req->file); wake_up(&req->waitq); if (end) end(fc, req); diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index bd5a772d8ccf..35e5cabb3b8c 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -288,12 +288,11 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, static void fuse_sync_release(struct fuse_conn *fc, struct fuse_file *ff, u64 nodeid, int flags) { - struct fuse_req *req; - - req = fuse_release_fill(ff, nodeid, flags, FUSE_RELEASE); - req->force = 1; - request_send(fc, req); - fuse_put_request(fc, req); + fuse_release_fill(ff, nodeid, flags, FUSE_RELEASE); + ff->reserved_req->force = 1; + request_send(fc, ff->reserved_req); + fuse_put_request(fc, ff->reserved_req); + kfree(ff); } /* @@ -859,6 +858,7 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir) struct page *page; struct inode *inode = file->f_path.dentry->d_inode; struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_file *ff = file->private_data; struct fuse_req *req; if (is_bad_inode(inode)) @@ -875,7 +875,7 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir) } req->num_pages = 1; req->pages[0] = page; - fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR); + fuse_read_fill(req, ff, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR); request_send(fc, req); nbytes = req->out.args[0].size; err = req->out.h.error; diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 11f22a3d728a..90ce7c5f7b59 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -54,6 +54,7 @@ struct fuse_file *fuse_file_alloc(void) kfree(ff); ff = NULL; } + atomic_set(&ff->count, 0); } return ff; } @@ -64,6 +65,22 @@ void fuse_file_free(struct fuse_file *ff) kfree(ff); } +static struct fuse_file *fuse_file_get(struct fuse_file *ff) +{ + atomic_inc(&ff->count); + return ff; +} + +static void fuse_file_put(struct fuse_file *ff) +{ + if (atomic_dec_and_test(&ff->count)) { + struct fuse_req *req = ff->reserved_req; + struct fuse_conn *fc = get_fuse_conn(req->dentry->d_inode); + request_send_background(fc, req); + kfree(ff); + } +} + void fuse_finish_open(struct inode *inode, struct file *file, struct fuse_file *ff, struct fuse_open_out *outarg) { @@ -72,7 +89,7 @@ void fuse_finish_open(struct inode *inode, struct file *file, if (!(outarg->open_flags & FOPEN_KEEP_CACHE)) invalidate_mapping_pages(inode->i_mapping, 0, -1); ff->fh = outarg->fh; - file->private_data = ff; + file->private_data = fuse_file_get(ff); } int fuse_open_common(struct inode *inode, struct file *file, int isdir) @@ -113,8 +130,7 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir) return err; } -struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, - int opcode) +void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode) { struct fuse_req *req = ff->reserved_req; struct fuse_release_in *inarg = &req->misc.release_in; @@ -126,25 +142,24 @@ struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, req->in.numargs = 1; req->in.args[0].size = sizeof(struct fuse_release_in); req->in.args[0].value = inarg; - kfree(ff); - - return req; } 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); - struct fuse_req *req; - - req = fuse_release_fill(ff, get_node_id(inode), file->f_flags, - isdir ? FUSE_RELEASEDIR : FUSE_RELEASE); + fuse_release_fill(ff, get_node_id(inode), file->f_flags, + isdir ? FUSE_RELEASEDIR : FUSE_RELEASE); /* Hold vfsmount and dentry until release is finished */ - req->vfsmount = mntget(file->f_path.mnt); - req->dentry = dget(file->f_path.dentry); - request_send_background(fc, req); + ff->reserved_req->vfsmount = mntget(file->f_path.mnt); + ff->reserved_req->dentry = dget(file->f_path.dentry); + /* + * Normally this will send the RELEASE request, + * however if some asynchronous READ or WRITE requests + * are outstanding, the sending will be delayed + */ + fuse_file_put(ff); } /* Return value is ignored by VFS */ @@ -264,10 +279,9 @@ static int fuse_fsync(struct file *file, struct dentry *de, int datasync) return fuse_fsync_common(file, de, datasync, 0); } -void fuse_read_fill(struct fuse_req *req, struct file *file, +void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff, struct inode *inode, loff_t pos, size_t count, int opcode) { - struct fuse_file *ff = file->private_data; struct fuse_read_in *inarg = &req->misc.read_in; inarg->fh = ff->fh; @@ -288,7 +302,8 @@ static size_t fuse_send_read(struct fuse_req *req, struct file *file, struct inode *inode, loff_t pos, size_t count) { struct fuse_conn *fc = get_fuse_conn(inode); - fuse_read_fill(req, file, inode, pos, count, FUSE_READ); + struct fuse_file *ff = file->private_data; + fuse_read_fill(req, ff, inode, pos, count, FUSE_READ); request_send(fc, req); return req->out.args[0].size; } @@ -337,20 +352,21 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req) SetPageError(page); unlock_page(page); } + if (req->ff) + fuse_file_put(req->ff); fuse_put_request(fc, req); } -static void fuse_send_readpages(struct fuse_req *req, struct file *file, +static void fuse_send_readpages(struct fuse_req *req, struct fuse_file *ff, struct inode *inode) { struct fuse_conn *fc = get_fuse_conn(inode); loff_t pos = page_offset(req->pages[0]); size_t count = req->num_pages << PAGE_CACHE_SHIFT; req->out.page_zeroing = 1; - fuse_read_fill(req, file, inode, pos, count, FUSE_READ); + fuse_read_fill(req, ff, inode, pos, count, FUSE_READ); if (fc->async_read) { - get_file(file); - req->file = file; + req->ff = fuse_file_get(ff); req->end = fuse_readpages_end; request_send_background(fc, req); } else { @@ -359,15 +375,15 @@ static void fuse_send_readpages(struct fuse_req *req, struct file *file, } } -struct fuse_readpages_data { +struct fuse_fill_data { struct fuse_req *req; - struct file *file; + struct fuse_file *ff; struct inode *inode; }; static int fuse_readpages_fill(void *_data, struct page *page) { - struct fuse_readpages_data *data = _data; + struct fuse_fill_data *data = _data; struct fuse_req *req = data->req; struct inode *inode = data->inode; struct fuse_conn *fc = get_fuse_conn(inode); @@ -376,7 +392,7 @@ static int fuse_readpages_fill(void *_data, struct page *page) (req->num_pages == FUSE_MAX_PAGES_PER_REQ || (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read || req->pages[req->num_pages - 1]->index + 1 != page->index)) { - fuse_send_readpages(req, data->file, inode); + fuse_send_readpages(req, data->ff, inode); data->req = req = fuse_get_req(fc); if (IS_ERR(req)) { unlock_page(page); @@ -393,14 +409,14 @@ static int fuse_readpages(struct file *file, struct address_space *mapping, { struct inode *inode = mapping->host; struct fuse_conn *fc = get_fuse_conn(inode); - struct fuse_readpages_data data; + struct fuse_fill_data data; int err; err = -EIO; if (is_bad_inode(inode)) goto out; - data.file = file; + data.ff = file->private_data; data.inode = inode; data.req = fuse_get_req(fc); err = PTR_ERR(data.req); @@ -410,7 +426,7 @@ static int fuse_readpages(struct file *file, struct address_space *mapping, err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data); if (!err) { if (data.req->num_pages) - fuse_send_readpages(data.req, file, inode); + fuse_send_readpages(data.req, data.ff, inode); else fuse_put_request(fc, data.req); } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 95bcb433d1b4..60683b787250 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -72,6 +72,9 @@ struct fuse_file { /** File handle used by userspace */ u64 fh; + + /** Refcount */ + atomic_t count; }; /** One input argument of a request */ @@ -216,7 +219,7 @@ struct fuse_req { unsigned page_offset; /** File used in the request (or NULL) */ - struct file *file; + struct fuse_file *ff; /** vfsmount used in release */ struct vfsmount *vfsmount; @@ -420,7 +423,7 @@ void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, /** * Initialize READ or READDIR request */ -void fuse_read_fill(struct fuse_req *req, struct file *file, +void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff, struct inode *inode, loff_t pos, size_t count, int opcode); /** @@ -433,9 +436,9 @@ 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); -/** */ -struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, - int opcode); +/** Fill in ff->reserved_req with a RELEASE request */ +void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode); + /** * Send RELEASE or RELEASEDIR request */ -- cgit v1.2.3-59-g8ed1b