From 37fb3a30b46237f23cfdf7ee09d49f9888dd13bf Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Mon, 8 Aug 2011 16:08:08 +0200 Subject: fuse: fix flock Commit a9ff4f87 "fuse: support BSD locking semantics" overlooked a number of issues with supporing flock locks over existing POSIX locking infrastructure: - it's not backward compatible, passing flock(2) calls to userspace unconditionally (if userspace sets FUSE_POSIX_LOCKS) - it doesn't cater for the fact that flock locks are automatically unlocked on file release - it doesn't take into account the fact that flock exclusive locks (write locks) don't need an fd opened for write. The last one invalidates the original premise of the patch that flock locks can be emulated with POSIX locks. This patch fixes the first two issues. The last one needs to be fixed in userspace if the filesystem assumed that a write lock will happen only on a file operned for write (as in the case of the current fuse library). Reported-by: Sebastian Pipping Signed-off-by: Miklos Szeredi --- fs/fuse/file.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'fs/fuse/file.c') diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 82a66466a24c..e32784924355 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -245,6 +245,12 @@ void fuse_release_common(struct file *file, int opcode) req = ff->reserved_req; fuse_prepare_release(ff, file->f_flags, opcode); + if (ff->flock) { + struct fuse_release_in *inarg = &req->misc.release.in; + inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK; + inarg->lock_owner = fuse_lock_owner_id(ff->fc, + (fl_owner_t) file); + } /* Hold vfsmount and dentry until release is finished */ path_get(&file->f_path); req->misc.release.path = file->f_path; @@ -1547,11 +1553,14 @@ static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl) struct fuse_conn *fc = get_fuse_conn(inode); int err; - if (fc->no_lock) { + if (fc->no_flock) { err = flock_lock_file_wait(file, fl); } else { + struct fuse_file *ff = file->private_data; + /* emulate flock with POSIX locks */ fl->fl_owner = (fl_owner_t) file; + ff->flock = true; err = fuse_setlk(file, fl, 1); } -- cgit v1.2.1 From b40cdd56dfa065c0832905e266b39f79419e6914 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Mon, 25 Jul 2011 22:35:34 +0200 Subject: fuse: delete dead .write_begin and .write_end aops Ever since 'ea9b990 fuse: implement perform_write', the .write_begin and .write_end aops have been dead code. Their task - acquiring a page from the page cache, sending out a write request and releasing the page again - is now done batch-wise to maximize the number of pages send per userspace request. Signed-off-by: Johannes Weiner Signed-off-by: Miklos Szeredi --- fs/fuse/file.c | 70 ---------------------------------------------------------- 1 file changed, 70 deletions(-) (limited to 'fs/fuse/file.c') diff --git a/fs/fuse/file.c b/fs/fuse/file.c index e32784924355..ab5b84ef4354 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -749,18 +749,6 @@ static size_t fuse_send_write(struct fuse_req *req, struct file *file, return req->misc.write.out.size; } -static int fuse_write_begin(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned flags, - struct page **pagep, void **fsdata) -{ - pgoff_t index = pos >> PAGE_CACHE_SHIFT; - - *pagep = grab_cache_page_write_begin(mapping, index, flags); - if (!*pagep) - return -ENOMEM; - return 0; -} - void fuse_write_update_size(struct inode *inode, loff_t pos) { struct fuse_conn *fc = get_fuse_conn(inode); @@ -773,62 +761,6 @@ void fuse_write_update_size(struct inode *inode, loff_t pos) spin_unlock(&fc->lock); } -static int fuse_buffered_write(struct file *file, struct inode *inode, - loff_t pos, unsigned count, struct page *page) -{ - int err; - size_t nres; - struct fuse_conn *fc = get_fuse_conn(inode); - unsigned offset = pos & (PAGE_CACHE_SIZE - 1); - struct fuse_req *req; - - if (is_bad_inode(inode)) - return -EIO; - - /* - * Make sure writepages on the same page are not mixed up with - * plain writes. - */ - fuse_wait_on_page_writeback(inode, page->index); - - req = fuse_get_req(fc); - if (IS_ERR(req)) - return PTR_ERR(req); - - req->in.argpages = 1; - req->num_pages = 1; - req->pages[0] = page; - req->page_offset = offset; - nres = fuse_send_write(req, file, pos, count, NULL); - err = req->out.h.error; - fuse_put_request(fc, req); - if (!err && !nres) - err = -EIO; - if (!err) { - pos += nres; - fuse_write_update_size(inode, pos); - if (count == PAGE_CACHE_SIZE) - SetPageUptodate(page); - } - fuse_invalidate_attr(inode); - return err ? err : nres; -} - -static int fuse_write_end(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned copied, - struct page *page, void *fsdata) -{ - struct inode *inode = mapping->host; - int res = 0; - - if (copied) - res = fuse_buffered_write(file, inode, pos, copied, page); - - unlock_page(page); - page_cache_release(page); - return res; -} - static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, struct inode *inode, loff_t pos, size_t count) @@ -2181,8 +2113,6 @@ static const struct address_space_operations fuse_file_aops = { .readpage = fuse_readpage, .writepage = fuse_writepage, .launder_page = fuse_launder_page, - .write_begin = fuse_write_begin, - .write_end = fuse_write_end, .readpages = fuse_readpages, .set_page_dirty = __set_page_dirty_nobuffers, .bmap = fuse_bmap, -- cgit v1.2.1 From 478e0841b3dce3edc2c67bf0fc51af30f582e9e2 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Mon, 25 Jul 2011 22:35:35 +0200 Subject: fuse: mark pages accessed when written to As fuse does not use the page cache library functions when userspace writes to a file, it did not benefit from 'c8236db mm: mark page accessed before we write_end()' that made sure pages are properly marked accessed when written to. Signed-off-by: Johannes Weiner Signed-off-by: Miklos Szeredi --- fs/fuse/file.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/fuse/file.c') diff --git a/fs/fuse/file.c b/fs/fuse/file.c index ab5b84ef4354..7155f49b2ef6 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -14,6 +14,7 @@ #include #include #include +#include static const struct file_operations fuse_direct_io_file_operations; @@ -834,6 +835,8 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req, pagefault_enable(); flush_dcache_page(page); + mark_page_accessed(page); + if (!tmp) { unlock_page(page); page_cache_release(page); -- cgit v1.2.1