diff options
Diffstat (limited to 'fs/btrfs/file.c')
-rw-r--r-- | fs/btrfs/file.c | 166 |
1 files changed, 102 insertions, 64 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 29ff749..79437c5 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -46,32 +46,42 @@ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes, struct page **prepared_pages, - const char __user *buf) + struct iov_iter *i) { - long page_fault = 0; - int i; + size_t copied; + int pg = 0; int offset = pos & (PAGE_CACHE_SIZE - 1); - for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) { + while (write_bytes > 0) { size_t count = min_t(size_t, PAGE_CACHE_SIZE - offset, write_bytes); - struct page *page = prepared_pages[i]; - fault_in_pages_readable(buf, count); + struct page *page = prepared_pages[pg]; +again: + if (unlikely(iov_iter_fault_in_readable(i, count))) + return -EFAULT; /* Copy data from userspace to the current page */ - kmap(page); - page_fault = __copy_from_user(page_address(page) + offset, - buf, count); + copied = iov_iter_copy_from_user(page, i, offset, count); + /* Flush processor's dcache for this page */ flush_dcache_page(page); - kunmap(page); - buf += count; - write_bytes -= count; + iov_iter_advance(i, copied); + write_bytes -= copied; - if (page_fault) - break; + if (unlikely(copied == 0)) { + count = min_t(size_t, PAGE_CACHE_SIZE - offset, + iov_iter_single_seg_count(i)); + goto again; + } + + if (unlikely(copied < PAGE_CACHE_SIZE - offset)) { + offset += copied; + } else { + pg++; + offset = 0; + } } - return page_fault ? -EFAULT : 0; + return 0; } /* @@ -126,8 +136,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans, end_of_last_block = start_pos + num_bytes - 1; err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block, NULL); - if (err) - return err; + BUG_ON(err); for (i = 0; i < num_pages; i++) { struct page *p = pages[i]; @@ -142,7 +151,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans, * at this time. */ } - return err; + return 0; } /* @@ -823,45 +832,46 @@ again: return 0; } -static ssize_t btrfs_file_write(struct file *file, const char __user *buf, - size_t count, loff_t *ppos) +static ssize_t btrfs_file_aio_write(struct kiocb *iocb, + const struct iovec *iov, + unsigned long nr_segs, loff_t pos) { - loff_t pos; + struct file *file = iocb->ki_filp; + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct page *pinned[2]; + struct page **pages = NULL; + struct iov_iter i; + loff_t *ppos = &iocb->ki_pos; loff_t start_pos; ssize_t num_written = 0; ssize_t err = 0; + size_t count; + size_t ocount; int ret = 0; - struct inode *inode = fdentry(file)->d_inode; - struct btrfs_root *root = BTRFS_I(inode)->root; - struct page **pages = NULL; int nrptrs; - struct page *pinned[2]; unsigned long first_index; unsigned long last_index; int will_write; + int buffered = 0; will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) || (file->f_flags & O_DIRECT)); - nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE, - PAGE_CACHE_SIZE / (sizeof(struct page *))); pinned[0] = NULL; pinned[1] = NULL; - pos = *ppos; start_pos = pos; vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); - /* do the reserve before the mutex lock in case we have to do some - * flushing. We wouldn't deadlock, but this is more polite. - */ - err = btrfs_reserve_metadata_for_delalloc(root, inode, 1); - if (err) - goto out_nolock; - mutex_lock(&inode->i_mutex); + err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); + if (err) + goto out; + count = ocount; + current->backing_dev_info = inode->i_mapping->backing_dev_info; err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); if (err) @@ -875,15 +885,53 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, goto out; file_update_time(file); + BTRFS_I(inode)->sequence++; + + if (unlikely(file->f_flags & O_DIRECT)) { + num_written = generic_file_direct_write(iocb, iov, &nr_segs, + pos, ppos, count, + ocount); + /* + * the generic O_DIRECT will update in-memory i_size after the + * DIOs are done. But our endio handlers that update the on + * disk i_size never update past the in memory i_size. So we + * need one more update here to catch any additions to the + * file + */ + if (inode->i_size != BTRFS_I(inode)->disk_i_size) { + btrfs_ordered_update_i_size(inode, inode->i_size, NULL); + mark_inode_dirty(inode); + } + if (num_written < 0) { + ret = num_written; + num_written = 0; + goto out; + } else if (num_written == count) { + /* pick up pos changes done by the generic code */ + pos = *ppos; + goto out; + } + /* + * We are going to do buffered for the rest of the range, so we + * need to make sure to invalidate the buffered pages when we're + * done. + */ + buffered = 1; + pos += num_written; + } + + iov_iter_init(&i, iov, nr_segs, count, num_written); + nrptrs = min((iov_iter_count(&i) + PAGE_CACHE_SIZE - 1) / + PAGE_CACHE_SIZE, PAGE_CACHE_SIZE / + (sizeof(struct page *))); pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); /* generic_write_checks can change our pos */ start_pos = pos; - BTRFS_I(inode)->sequence++; first_index = pos >> PAGE_CACHE_SHIFT; - last_index = (pos + count) >> PAGE_CACHE_SHIFT; + last_index = (pos + iov_iter_count(&i)) >> PAGE_CACHE_SHIFT; /* * there are lots of better ways to do this, but this code @@ -900,7 +948,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, unlock_page(pinned[0]); } } - if ((pos + count) & (PAGE_CACHE_SIZE - 1)) { + if ((pos + iov_iter_count(&i)) & (PAGE_CACHE_SIZE - 1)) { pinned[1] = grab_cache_page(inode->i_mapping, last_index); if (!PageUptodate(pinned[1])) { ret = btrfs_readpage(NULL, pinned[1]); @@ -911,10 +959,10 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, } } - while (count > 0) { + while (iov_iter_count(&i) > 0) { size_t offset = pos & (PAGE_CACHE_SIZE - 1); - size_t write_bytes = min(count, nrptrs * - (size_t)PAGE_CACHE_SIZE - + size_t write_bytes = min(iov_iter_count(&i), + nrptrs * (size_t)PAGE_CACHE_SIZE - offset); size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; @@ -922,7 +970,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, WARN_ON(num_pages > nrptrs); memset(pages, 0, sizeof(struct page *) * nrptrs); - ret = btrfs_check_data_free_space(root, inode, write_bytes); + ret = btrfs_delalloc_reserve_space(inode, write_bytes); if (ret) goto out; @@ -930,26 +978,20 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, pos, first_index, last_index, write_bytes); if (ret) { - btrfs_free_reserved_data_space(root, inode, - write_bytes); + btrfs_delalloc_release_space(inode, write_bytes); goto out; } ret = btrfs_copy_from_user(pos, num_pages, - write_bytes, pages, buf); - if (ret) { - btrfs_free_reserved_data_space(root, inode, - write_bytes); - btrfs_drop_pages(pages, num_pages); - goto out; + write_bytes, pages, &i); + if (ret == 0) { + dirty_and_release_pages(NULL, root, file, pages, + num_pages, pos, write_bytes); } - ret = dirty_and_release_pages(NULL, root, file, pages, - num_pages, pos, write_bytes); btrfs_drop_pages(pages, num_pages); if (ret) { - btrfs_free_reserved_data_space(root, inode, - write_bytes); + btrfs_delalloc_release_space(inode, write_bytes); goto out; } @@ -965,8 +1007,6 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, btrfs_throttle(root); } - buf += write_bytes; - count -= write_bytes; pos += write_bytes; num_written += write_bytes; @@ -976,9 +1016,7 @@ out: mutex_unlock(&inode->i_mutex); if (ret) err = ret; - btrfs_unreserve_metadata_for_delalloc(root, inode, 1); -out_nolock: kfree(pages); if (pinned[0]) page_cache_release(pinned[0]); @@ -1008,7 +1046,7 @@ out_nolock: num_written = err; if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { - trans = btrfs_start_transaction(root, 1); + trans = btrfs_start_transaction(root, 0); ret = btrfs_log_dentry_safe(trans, root, file->f_dentry); if (ret == 0) { @@ -1023,7 +1061,7 @@ out_nolock: btrfs_end_transaction(trans, root); } } - if (file->f_flags & O_DIRECT) { + if (file->f_flags & O_DIRECT && buffered) { invalidate_mapping_pages(inode->i_mapping, start_pos >> PAGE_CACHE_SHIFT, (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT); @@ -1104,9 +1142,9 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync) if (file && file->private_data) btrfs_ioctl_trans_end(file); - trans = btrfs_start_transaction(root, 1); - if (!trans) { - ret = -ENOMEM; + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); goto out; } @@ -1161,7 +1199,7 @@ const struct file_operations btrfs_file_operations = { .read = do_sync_read, .aio_read = generic_file_aio_read, .splice_read = generic_file_splice_read, - .write = btrfs_file_write, + .aio_write = btrfs_file_aio_write, .mmap = btrfs_file_mmap, .open = generic_file_open, .release = btrfs_release_file, |