diff options
Diffstat (limited to 'fs/btrfs/file.c')
-rw-r--r-- | fs/btrfs/file.c | 506 |
1 files changed, 272 insertions, 234 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index c1d3a818731..75899a01dde 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -45,14 +45,14 @@ * and be replaced with calls into generic code. */ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, - int write_bytes, + size_t write_bytes, struct page **prepared_pages, struct iov_iter *i) { size_t copied = 0; + size_t total_copied = 0; int pg = 0; int offset = pos & (PAGE_CACHE_SIZE - 1); - int total_copied = 0; while (write_bytes > 0) { size_t count = min_t(size_t, @@ -70,14 +70,26 @@ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, /* Flush processor's dcache for this page */ flush_dcache_page(page); + + /* + * if we get a partial write, we can end up with + * partially up to date pages. These add + * a lot of complexity, so make sure they don't + * happen by forcing this copy to be retried. + * + * The rest of the btrfs_file_write code will fall + * back to page at a time copies after we return 0. + */ + if (!PageUptodate(page) && copied < count) + copied = 0; + iov_iter_advance(i, copied); write_bytes -= copied; total_copied += copied; /* Return to btrfs_file_aio_write to fault page */ - if (unlikely(copied == 0)) { + if (unlikely(copied == 0)) break; - } if (unlikely(copied < PAGE_CACHE_SIZE - offset)) { offset += copied; @@ -92,12 +104,10 @@ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, /* * unlocks pages after btrfs_file_write is done with them */ -static noinline void btrfs_drop_pages(struct page **pages, size_t num_pages) +void btrfs_drop_pages(struct page **pages, size_t num_pages) { size_t i; for (i = 0; i < num_pages; i++) { - if (!pages[i]) - break; /* page checked is some magic around finding pages that * have been modified without going through btrfs_set_page_dirty * clear it here @@ -117,17 +127,13 @@ static noinline void btrfs_drop_pages(struct page **pages, size_t num_pages) * this also makes the decision about creating an inline extent vs * doing real data extents, marking pages dirty and delalloc as required. */ -static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct file *file, - struct page **pages, - size_t num_pages, - loff_t pos, - size_t write_bytes) +int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode, + struct page **pages, size_t num_pages, + loff_t pos, size_t write_bytes, + struct extent_state **cached) { int err = 0; int i; - struct inode *inode = fdentry(file)->d_inode; u64 num_bytes; u64 start_pos; u64 end_of_last_block; @@ -140,8 +146,9 @@ 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); - BUG_ON(err); + cached); + if (err) + return err; for (i = 0; i < num_pages; i++) { struct page *p = pages[i]; @@ -149,13 +156,14 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans, ClearPageChecked(p); set_page_dirty(p); } - if (end_pos > isize) { + + /* + * we've only changed i_size in ram, and we haven't updated + * the disk i_size. There is no need to log the inode + * at this time. + */ + if (end_pos > isize) i_size_write(inode, end_pos); - /* we've only changed i_size in ram, and we haven't updated - * the disk i_size. There is no need to log the inode - * at this time. - */ - } return 0; } @@ -186,6 +194,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, split = alloc_extent_map(GFP_NOFS); if (!split2) split2 = alloc_extent_map(GFP_NOFS); + BUG_ON(!split || !split2); write_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, start, len); @@ -596,6 +605,8 @@ again: key.offset = split; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; if (ret > 0 && path->slots[0] > 0) path->slots[0]--; @@ -762,6 +773,27 @@ out: } /* + * on error we return an unlocked page and the error value + * on success we return a locked page and 0 + */ +static int prepare_uptodate_page(struct page *page, u64 pos) +{ + int ret = 0; + + if ((pos & (PAGE_CACHE_SIZE - 1)) && !PageUptodate(page)) { + ret = btrfs_readpage(NULL, page); + if (ret) + return ret; + lock_page(page); + if (!PageUptodate(page)) { + unlock_page(page); + return -EIO; + } + } + return 0; +} + +/* * this gets pages into the page cache and locks them down, it also properly * waits for data=ordered extents to finish before allowing the pages to be * modified. @@ -776,6 +808,7 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file, unsigned long index = pos >> PAGE_CACHE_SHIFT; struct inode *inode = fdentry(file)->d_inode; int err = 0; + int faili = 0; u64 start_pos; u64 last_pos; @@ -783,25 +816,33 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file, last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT; if (start_pos > inode->i_size) { - err = btrfs_cont_expand(inode, start_pos); + err = btrfs_cont_expand(inode, i_size_read(inode), start_pos); if (err) return err; } - memset(pages, 0, num_pages * sizeof(struct page *)); again: for (i = 0; i < num_pages; i++) { pages[i] = grab_cache_page(inode->i_mapping, index + i); if (!pages[i]) { - int c; - for (c = i - 1; c >= 0; c--) { - unlock_page(pages[c]); - page_cache_release(pages[c]); - } - return -ENOMEM; + faili = i - 1; + err = -ENOMEM; + goto fail; + } + + if (i == 0) + err = prepare_uptodate_page(pages[i], pos); + if (i == num_pages - 1) + err = prepare_uptodate_page(pages[i], + pos + write_bytes); + if (err) { + page_cache_release(pages[i]); + faili = i - 1; + goto fail; } wait_on_page_writeback(pages[i]); } + err = 0; if (start_pos < inode->i_size) { struct btrfs_ordered_extent *ordered; lock_extent_bits(&BTRFS_I(inode)->io_tree, @@ -841,191 +882,103 @@ again: WARN_ON(!PageLocked(pages[i])); } return 0; +fail: + while (faili >= 0) { + unlock_page(pages[faili]); + page_cache_release(pages[faili]); + faili--; + } + return err; + } -static ssize_t btrfs_file_aio_write(struct kiocb *iocb, - const struct iovec *iov, - unsigned long nr_segs, loff_t pos) +static noinline ssize_t __btrfs_buffered_write(struct file *file, + struct iov_iter *i, + 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; - int nrptrs; unsigned long first_index; unsigned long last_index; - int will_write; - int buffered = 0; - int copied = 0; - int dirty_pages = 0; - - will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) || - (file->f_flags & O_DIRECT)); - - pinned[0] = NULL; - pinned[1] = NULL; - - start_pos = pos; - - vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); - - 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) - goto out; - - if (count == 0) - goto out; - - err = file_remove_suid(file); - if (err) - goto out; - - /* - * If BTRFS flips readonly due to some impossible error - * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR), - * although we have opened a file as writable, we have - * to stop this write operation to ensure FS consistency. - */ - if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { - err = -EROFS; - 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; - } + size_t num_written = 0; + int nrptrs; + int ret = 0; - iov_iter_init(&i, iov, nr_segs, count, num_written); - nrptrs = min((iov_iter_count(&i) + PAGE_CACHE_SIZE - 1) / + 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); - if (!pages) { - ret = -ENOMEM; - goto out; - } - - /* generic_write_checks can change our pos */ - start_pos = pos; + if (!pages) + return -ENOMEM; first_index = pos >> PAGE_CACHE_SHIFT; - last_index = (pos + iov_iter_count(&i)) >> 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 - * makes sure the first and last page in the file range are - * up to date and ready for cow - */ - if ((pos & (PAGE_CACHE_SIZE - 1))) { - pinned[0] = grab_cache_page(inode->i_mapping, first_index); - if (!PageUptodate(pinned[0])) { - ret = btrfs_readpage(NULL, pinned[0]); - BUG_ON(ret); - wait_on_page_locked(pinned[0]); - } else { - unlock_page(pinned[0]); - } - } - 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]); - BUG_ON(ret); - wait_on_page_locked(pinned[1]); - } else { - unlock_page(pinned[1]); - } - } - - while (iov_iter_count(&i) > 0) { + while (iov_iter_count(i) > 0) { size_t offset = pos & (PAGE_CACHE_SIZE - 1); - size_t write_bytes = min(iov_iter_count(&i), + size_t write_bytes = min(iov_iter_count(i), nrptrs * (size_t)PAGE_CACHE_SIZE - offset); size_t num_pages = (write_bytes + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + size_t dirty_pages; + size_t copied; WARN_ON(num_pages > nrptrs); - memset(pages, 0, sizeof(struct page *) * nrptrs); /* * Fault pages before locking them in prepare_pages * to avoid recursive lock */ - if (unlikely(iov_iter_fault_in_readable(&i, write_bytes))) { + if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) { ret = -EFAULT; - goto out; + break; } ret = btrfs_delalloc_reserve_space(inode, num_pages << PAGE_CACHE_SHIFT); if (ret) - goto out; + break; + /* + * This is going to setup the pages array with the number of + * pages we want, so we don't really need to worry about the + * contents of pages from loop to loop + */ ret = prepare_pages(root, file, pages, num_pages, pos, first_index, last_index, write_bytes); if (ret) { btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT); - goto out; + break; } copied = btrfs_copy_from_user(pos, num_pages, - write_bytes, pages, &i); - dirty_pages = (copied + offset + PAGE_CACHE_SIZE - 1) >> - PAGE_CACHE_SHIFT; + write_bytes, pages, i); + /* + * if we have trouble faulting in the pages, fall + * back to one page at a time + */ + if (copied < write_bytes) + nrptrs = 1; + + if (copied == 0) + dirty_pages = 0; + else + dirty_pages = (copied + offset + + PAGE_CACHE_SIZE - 1) >> + PAGE_CACHE_SHIFT; + + /* + * If we had a short copy we need to release the excess delaloc + * bytes we reserved. We need to increment outstanding_extents + * because btrfs_delalloc_release_space will decrement it, but + * we still have an outstanding extent for the chunk we actually + * managed to copy. + */ if (num_pages > dirty_pages) { if (copied > 0) atomic_inc( @@ -1036,43 +989,157 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, } if (copied > 0) { - dirty_and_release_pages(NULL, root, file, pages, - dirty_pages, pos, copied); + ret = btrfs_dirty_pages(root, inode, pages, + dirty_pages, pos, copied, + NULL); + if (ret) { + btrfs_delalloc_release_space(inode, + dirty_pages << PAGE_CACHE_SHIFT); + btrfs_drop_pages(pages, num_pages); + break; + } } btrfs_drop_pages(pages, num_pages); - if (copied > 0) { - if (will_write) { - filemap_fdatawrite_range(inode->i_mapping, pos, - pos + copied - 1); - } else { - balance_dirty_pages_ratelimited_nr( - inode->i_mapping, - dirty_pages); - if (dirty_pages < - (root->leafsize >> PAGE_CACHE_SHIFT) + 1) - btrfs_btree_balance_dirty(root, 1); - btrfs_throttle(root); - } - } + cond_resched(); + + balance_dirty_pages_ratelimited_nr(inode->i_mapping, + dirty_pages); + if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1) + btrfs_btree_balance_dirty(root, 1); + btrfs_throttle(root); pos += copied; num_written += copied; + } - cond_resched(); + kfree(pages); + + return num_written ? num_written : ret; +} + +static ssize_t __btrfs_direct_write(struct kiocb *iocb, + const struct iovec *iov, + unsigned long nr_segs, loff_t pos, + loff_t *ppos, size_t count, size_t ocount) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = fdentry(file)->d_inode; + struct iov_iter i; + ssize_t written; + ssize_t written_buffered; + loff_t endbyte; + int err; + + 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 (written < 0 || written == count) + return written; + + pos += written; + count -= written; + iov_iter_init(&i, iov, nr_segs, count, written); + written_buffered = __btrfs_buffered_write(file, &i, pos); + if (written_buffered < 0) { + err = written_buffered; + goto out; + } + endbyte = pos + written_buffered - 1; + err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte); + if (err) + goto out; + written += written_buffered; + *ppos = pos + written_buffered; + invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT, + endbyte >> PAGE_CACHE_SHIFT); out: - mutex_unlock(&inode->i_mutex); - if (ret) - err = ret; + return written ? written : err; +} - kfree(pages); - if (pinned[0]) - page_cache_release(pinned[0]); - if (pinned[1]) - page_cache_release(pinned[1]); - *ppos = pos; +static ssize_t btrfs_file_aio_write(struct kiocb *iocb, + const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = fdentry(file)->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; + loff_t *ppos = &iocb->ki_pos; + ssize_t num_written = 0; + ssize_t err = 0; + size_t count, ocount; + + vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); + + mutex_lock(&inode->i_mutex); + + err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); + if (err) { + mutex_unlock(&inode->i_mutex); + 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) { + mutex_unlock(&inode->i_mutex); + goto out; + } + + if (count == 0) { + mutex_unlock(&inode->i_mutex); + goto out; + } + + err = file_remove_suid(file); + if (err) { + mutex_unlock(&inode->i_mutex); + goto out; + } + + /* + * If BTRFS flips readonly due to some impossible error + * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR), + * although we have opened a file as writable, we have + * to stop this write operation to ensure FS consistency. + */ + if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { + mutex_unlock(&inode->i_mutex); + err = -EROFS; + goto out; + } + + file_update_time(file); + BTRFS_I(inode)->sequence++; + + if (unlikely(file->f_flags & O_DIRECT)) { + num_written = __btrfs_direct_write(iocb, iov, nr_segs, + pos, ppos, count, ocount); + } else { + struct iov_iter i; + + iov_iter_init(&i, iov, nr_segs, count, num_written); + + num_written = __btrfs_buffered_write(file, &i, pos); + if (num_written > 0) + *ppos = pos + num_written; + } + + mutex_unlock(&inode->i_mutex); /* * we want to make sure fsync finds this change @@ -1087,43 +1154,12 @@ out: * one running right now. */ BTRFS_I(inode)->last_trans = root->fs_info->generation + 1; - - if (num_written > 0 && will_write) { - struct btrfs_trans_handle *trans; - - err = btrfs_wait_ordered_range(inode, start_pos, num_written); - if (err) + if (num_written > 0 || num_written == -EIOCBQUEUED) { + err = generic_write_sync(file, pos, num_written); + if (err < 0 && num_written > 0) num_written = err; - - if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { - trans = btrfs_start_transaction(root, 0); - if (IS_ERR(trans)) { - num_written = PTR_ERR(trans); - goto done; - } - mutex_lock(&inode->i_mutex); - ret = btrfs_log_dentry_safe(trans, root, - file->f_dentry); - mutex_unlock(&inode->i_mutex); - if (ret == 0) { - ret = btrfs_sync_log(trans, root); - if (ret == 0) - btrfs_end_transaction(trans, root); - else - btrfs_commit_transaction(trans, root); - } else if (ret != BTRFS_NO_LOG_SYNC) { - btrfs_commit_transaction(trans, root); - } else { - btrfs_end_transaction(trans, root); - } - } - 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); - } } -done: +out: current->backing_dev_info = NULL; return num_written ? num_written : err; } @@ -1166,6 +1202,7 @@ int btrfs_sync_file(struct file *file, int datasync) int ret = 0; struct btrfs_trans_handle *trans; + trace_btrfs_sync_file(file, datasync); /* we wait first, since the writeback may change the inode */ root->log_batch++; @@ -1293,7 +1330,8 @@ static long btrfs_fallocate(struct file *file, int mode, goto out; if (alloc_start > inode->i_size) { - ret = btrfs_cont_expand(inode, alloc_start); + ret = btrfs_cont_expand(inode, i_size_read(inode), + alloc_start); if (ret) goto out; } |