diff options
Diffstat (limited to 'fs/fuse/file.c')
-rw-r--r-- | fs/fuse/file.c | 287 |
1 files changed, 232 insertions, 55 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index fd06d1e..13f8bde 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -188,6 +188,22 @@ int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, } EXPORT_SYMBOL_GPL(fuse_do_open); +static void fuse_link_write_file(struct file *file) +{ + struct inode *inode = file_inode(file); + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_inode *fi = get_fuse_inode(inode); + struct fuse_file *ff = file->private_data; + /* + * file may be written through mmap, so chain it onto the + * inodes's write_file list + */ + spin_lock(&fc->lock); + if (list_empty(&ff->write_entry)) + list_add(&ff->write_entry, &fi->write_files); + spin_unlock(&fc->lock); +} + void fuse_finish_open(struct inode *inode, struct file *file) { struct fuse_file *ff = file->private_data; @@ -208,6 +224,8 @@ void fuse_finish_open(struct inode *inode, struct file *file) spin_unlock(&fc->lock); fuse_invalidate_attr(inode); } + if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache) + fuse_link_write_file(file); } int fuse_open_common(struct inode *inode, struct file *file, bool isdir) @@ -292,6 +310,15 @@ static int fuse_open(struct inode *inode, struct file *file) static int fuse_release(struct inode *inode, struct file *file) { + struct fuse_conn *fc = get_fuse_conn(inode); + + /* see fuse_vma_close() for !writeback_cache case */ + if (fc->writeback_cache) + filemap_write_and_wait(file->f_mapping); + + if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state)) + fuse_flush_mtime(file, true); + fuse_release_common(file, FUSE_RELEASE); /* return value is ignored by VFS */ @@ -333,12 +360,13 @@ u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id) } /* - * Check if page is under writeback + * Check if any page in a range is under writeback * * This is currently done by walking the list of writepage requests * for the inode, which can be pretty inefficient. */ -static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) +static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from, + pgoff_t idx_to) { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); @@ -351,8 +379,8 @@ static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) BUG_ON(req->inode != inode); curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT; - if (curr_index <= index && - index < curr_index + req->num_pages) { + if (idx_from < curr_index + req->num_pages && + curr_index <= idx_to) { found = true; break; } @@ -362,6 +390,11 @@ static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) return found; } +static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) +{ + return fuse_range_is_writeback(inode, index, index); +} + /* * Wait for page writeback to be completed. * @@ -376,6 +409,21 @@ static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index) return 0; } +/* + * Wait for all pending writepages on the inode to finish. + * + * This is currently done by blocking further writes with FUSE_NOWRITE + * and waiting for all sent writes to complete. + * + * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage + * could conflict with truncation. + */ +static void fuse_sync_writes(struct inode *inode) +{ + fuse_set_nowrite(inode); + fuse_release_nowrite(inode); +} + static int fuse_flush(struct file *file, fl_owner_t id) { struct inode *inode = file_inode(file); @@ -391,6 +439,14 @@ static int fuse_flush(struct file *file, fl_owner_t id) if (fc->no_flush) return 0; + err = filemap_write_and_wait(file->f_mapping); + if (err) + return err; + + mutex_lock(&inode->i_mutex); + fuse_sync_writes(inode); + mutex_unlock(&inode->i_mutex); + req = fuse_get_req_nofail_nopages(fc, file); memset(&inarg, 0, sizeof(inarg)); inarg.fh = ff->fh; @@ -411,21 +467,6 @@ static int fuse_flush(struct file *file, fl_owner_t id) return err; } -/* - * Wait for all pending writepages on the inode to finish. - * - * This is currently done by blocking further writes with FUSE_NOWRITE - * and waiting for all sent writes to complete. - * - * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage - * could conflict with truncation. - */ -static void fuse_sync_writes(struct inode *inode) -{ - fuse_set_nowrite(inode); - fuse_release_nowrite(inode); -} - int fuse_fsync_common(struct file *file, loff_t start, loff_t end, int datasync, int isdir) { @@ -459,6 +500,12 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end, fuse_sync_writes(inode); + if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state)) { + int err = fuse_flush_mtime(file, false); + if (err) + goto out; + } + req = fuse_get_req_nopages(fc); if (IS_ERR(req)) { err = PTR_ERR(req); @@ -655,7 +702,33 @@ static void fuse_read_update_size(struct inode *inode, loff_t size, spin_unlock(&fc->lock); } -static int fuse_readpage(struct file *file, struct page *page) +static void fuse_short_read(struct fuse_req *req, struct inode *inode, + u64 attr_ver) +{ + size_t num_read = req->out.args[0].size; + struct fuse_conn *fc = get_fuse_conn(inode); + + if (fc->writeback_cache) { + /* + * A hole in a file. Some data after the hole are in page cache, + * but have not reached the client fs yet. So, the hole is not + * present there. + */ + int i; + int start_idx = num_read >> PAGE_CACHE_SHIFT; + size_t off = num_read & (PAGE_CACHE_SIZE - 1); + + for (i = start_idx; i < req->num_pages; i++) { + zero_user_segment(req->pages[i], off, PAGE_CACHE_SIZE); + off = 0; + } + } else { + loff_t pos = page_offset(req->pages[0]) + num_read; + fuse_read_update_size(inode, pos, attr_ver); + } +} + +static int fuse_do_readpage(struct file *file, struct page *page) { struct fuse_io_priv io = { .async = 0, .file = file }; struct inode *inode = page->mapping->host; @@ -667,10 +740,6 @@ static int fuse_readpage(struct file *file, struct page *page) u64 attr_ver; int err; - err = -EIO; - if (is_bad_inode(inode)) - goto out; - /* * Page writeback can extend beyond the lifetime of the * page-cache page, so make sure we read a properly synced @@ -679,9 +748,8 @@ static int fuse_readpage(struct file *file, struct page *page) fuse_wait_on_page_writeback(inode, page->index); req = fuse_get_req(fc, 1); - err = PTR_ERR(req); if (IS_ERR(req)) - goto out; + return PTR_ERR(req); attr_ver = fuse_get_attr_version(fc); @@ -692,18 +760,32 @@ static int fuse_readpage(struct file *file, struct page *page) req->page_descs[0].length = count; num_read = fuse_send_read(req, &io, pos, count, NULL); err = req->out.h.error; - fuse_put_request(fc, req); if (!err) { /* * Short read means EOF. If file size is larger, truncate it */ if (num_read < count) - fuse_read_update_size(inode, pos + num_read, attr_ver); + fuse_short_read(req, inode, attr_ver); SetPageUptodate(page); } + fuse_put_request(fc, req); + + return err; +} + +static int fuse_readpage(struct file *file, struct page *page) +{ + struct inode *inode = page->mapping->host; + int err; + + err = -EIO; + if (is_bad_inode(inode)) + goto out; + + err = fuse_do_readpage(file, page); fuse_invalidate_atime(inode); out: unlock_page(page); @@ -726,13 +808,9 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req) /* * Short read means EOF. If file size is larger, truncate it */ - if (!req->out.h.error && num_read < count) { - loff_t pos; + if (!req->out.h.error && num_read < count) + fuse_short_read(req, inode, req->misc.read.attr_ver); - pos = page_offset(req->pages[0]) + num_read; - fuse_read_update_size(inode, pos, - req->misc.read.attr_ver); - } fuse_invalidate_atime(inode); } @@ -922,16 +1000,21 @@ static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io, return req->misc.write.out.size; } -void fuse_write_update_size(struct inode *inode, loff_t pos) +bool fuse_write_update_size(struct inode *inode, loff_t pos) { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); + bool ret = false; spin_lock(&fc->lock); fi->attr_version = ++fc->attr_version; - if (pos > inode->i_size) + if (pos > inode->i_size) { i_size_write(inode, pos); + ret = true; + } spin_unlock(&fc->lock); + + return ret; } static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, @@ -1114,6 +1197,15 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, struct iov_iter i; loff_t endbyte = 0; + if (get_fuse_conn(inode)->writeback_cache) { + /* Update size (EOF optimization) and mode (SUID clearing) */ + err = fuse_update_attributes(mapping->host, NULL, file, NULL); + if (err) + return err; + + return generic_file_aio_write(iocb, iov, nr_segs, pos); + } + WARN_ON(iocb->ki_pos != pos); ocount = 0; @@ -1286,13 +1378,18 @@ static inline int fuse_iter_npages(const struct iov_iter *ii_p) ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov, unsigned long nr_segs, size_t count, loff_t *ppos, - int write) + int flags) { + int write = flags & FUSE_DIO_WRITE; + int cuse = flags & FUSE_DIO_CUSE; struct file *file = io->file; + struct inode *inode = file->f_mapping->host; struct fuse_file *ff = file->private_data; struct fuse_conn *fc = ff->fc; size_t nmax = write ? fc->max_write : fc->max_read; loff_t pos = *ppos; + pgoff_t idx_from = pos >> PAGE_CACHE_SHIFT; + pgoff_t idx_to = (pos + count - 1) >> PAGE_CACHE_SHIFT; ssize_t res = 0; struct fuse_req *req; struct iov_iter ii; @@ -1306,6 +1403,14 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov, if (IS_ERR(req)) return PTR_ERR(req); + if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) { + if (!write) + mutex_lock(&inode->i_mutex); + fuse_sync_writes(inode); + if (!write) + mutex_unlock(&inode->i_mutex); + } + while (count) { size_t nres; fl_owner_t owner = current->files; @@ -1394,7 +1499,8 @@ static ssize_t __fuse_direct_write(struct fuse_io_priv *io, res = generic_write_checks(file, ppos, &count, 0); if (!res) - res = fuse_direct_io(io, iov, nr_segs, count, ppos, 1); + res = fuse_direct_io(io, iov, nr_segs, count, ppos, + FUSE_DIO_WRITE); fuse_invalidate_attr(inode); @@ -1882,6 +1988,77 @@ out: return err; } +/* + * It's worthy to make sure that space is reserved on disk for the write, + * but how to implement it without killing performance need more thinking. + */ +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; + struct fuse_conn *fc = get_fuse_conn(file->f_dentry->d_inode); + struct page *page; + loff_t fsize; + int err = -ENOMEM; + + WARN_ON(!fc->writeback_cache); + + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + goto error; + + fuse_wait_on_page_writeback(mapping->host, page->index); + + if (PageUptodate(page) || len == PAGE_CACHE_SIZE) + goto success; + /* + * Check if the start this page comes after the end of file, in which + * case the readpage can be optimized away. + */ + fsize = i_size_read(mapping->host); + if (fsize <= (pos & PAGE_CACHE_MASK)) { + size_t off = pos & ~PAGE_CACHE_MASK; + if (off) + zero_user_segment(page, 0, off); + goto success; + } + err = fuse_do_readpage(file, page); + if (err) + goto cleanup; +success: + *pagep = page; + return 0; + +cleanup: + unlock_page(page); + page_cache_release(page); +error: + return err; +} + +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 = page->mapping->host; + + if (!PageUptodate(page)) { + /* Zero any unwritten bytes at the end of the page */ + size_t endoff = (pos + copied) & ~PAGE_CACHE_MASK; + if (endoff) + zero_user_segment(page, endoff, PAGE_CACHE_SIZE); + SetPageUptodate(page); + } + + fuse_write_update_size(inode, pos + copied); + set_page_dirty(page); + unlock_page(page); + page_cache_release(page); + + return copied; +} + static int fuse_launder_page(struct page *page) { int err = 0; @@ -1937,26 +2114,16 @@ static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) static const struct vm_operations_struct fuse_file_vm_ops = { .close = fuse_vma_close, .fault = filemap_fault, + .map_pages = filemap_map_pages, .page_mkwrite = fuse_page_mkwrite, .remap_pages = generic_file_remap_pages, }; static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) { - if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) { - struct inode *inode = file_inode(file); - struct fuse_conn *fc = get_fuse_conn(inode); - struct fuse_inode *fi = get_fuse_inode(inode); - struct fuse_file *ff = file->private_data; - /* - * file may be written through mmap, so chain it onto the - * inodes's write_file list - */ - spin_lock(&fc->lock); - if (list_empty(&ff->write_entry)) - list_add(&ff->write_entry, &fi->write_files); - spin_unlock(&fc->lock); - } + if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) + fuse_link_write_file(file); + file_accessed(file); vma->vm_ops = &fuse_file_vm_ops; return 0; @@ -2603,7 +2770,7 @@ static void fuse_register_polled_file(struct fuse_conn *fc, { spin_lock(&fc->lock); if (RB_EMPTY_NODE(&ff->polled_node)) { - struct rb_node **link, *parent; + struct rb_node **link, *uninitialized_var(parent); link = fuse_find_polled_node(fc, ff->kh, &parent); BUG_ON(*link); @@ -2847,8 +3014,16 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, goto out; /* we could have extended the file */ - if (!(mode & FALLOC_FL_KEEP_SIZE)) - fuse_write_update_size(inode, offset + length); + if (!(mode & FALLOC_FL_KEEP_SIZE)) { + bool changed = fuse_write_update_size(inode, offset + length); + + if (changed && fc->writeback_cache) { + struct fuse_inode *fi = get_fuse_inode(inode); + + inode->i_mtime = current_fs_time(inode->i_sb); + set_bit(FUSE_I_MTIME_DIRTY, &fi->state); + } + } if (mode & FALLOC_FL_PUNCH_HOLE) truncate_pagecache_range(inode, offset, offset + length - 1); @@ -2912,6 +3087,8 @@ static const struct address_space_operations fuse_file_aops = { .set_page_dirty = __set_page_dirty_nobuffers, .bmap = fuse_bmap, .direct_IO = fuse_direct_IO, + .write_begin = fuse_write_begin, + .write_end = fuse_write_end, }; void fuse_init_file_inode(struct inode *inode) |