| /* |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/pagemap.h> |
| #include <linux/highmem.h> |
| #include <linux/time.h> |
| #include <linux/init.h> |
| #include <linux/string.h> |
| #include <linux/backing-dev.h> |
| #include <linux/mpage.h> |
| #include <linux/swap.h> |
| #include <linux/writeback.h> |
| #include <linux/statfs.h> |
| #include <linux/compat.h> |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "btrfs_inode.h" |
| #include "ioctl.h" |
| #include "print-tree.h" |
| #include "tree-log.h" |
| #include "locking.h" |
| #include "compat.h" |
| |
| |
| /* simple helper to fault in pages and copy. This should go away |
| * and be replaced with calls into generic code. |
| */ |
| static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, |
| int write_bytes, |
| struct page **prepared_pages, |
| const char __user *buf) |
| { |
| long page_fault = 0; |
| int i; |
| int offset = pos & (PAGE_CACHE_SIZE - 1); |
| |
| for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 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); |
| |
| /* Copy data from userspace to the current page */ |
| kmap(page); |
| page_fault = __copy_from_user(page_address(page) + offset, |
| buf, count); |
| /* Flush processor's dcache for this page */ |
| flush_dcache_page(page); |
| kunmap(page); |
| buf += count; |
| write_bytes -= count; |
| |
| if (page_fault) |
| break; |
| } |
| return page_fault ? -EFAULT : 0; |
| } |
| |
| /* |
| * unlocks pages after btrfs_file_write is done with them |
| */ |
| static noinline 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 |
| */ |
| ClearPageChecked(pages[i]); |
| unlock_page(pages[i]); |
| mark_page_accessed(pages[i]); |
| page_cache_release(pages[i]); |
| } |
| } |
| |
| /* |
| * after copy_from_user, pages need to be dirtied and we need to make |
| * sure holes are created between the current EOF and the start of |
| * any next extents (if required). |
| * |
| * 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 err = 0; |
| int i; |
| struct inode *inode = fdentry(file)->d_inode; |
| u64 num_bytes; |
| u64 start_pos; |
| u64 end_of_last_block; |
| u64 end_pos = pos + write_bytes; |
| loff_t isize = i_size_read(inode); |
| |
| start_pos = pos & ~((u64)root->sectorsize - 1); |
| num_bytes = (write_bytes + pos - start_pos + |
| root->sectorsize - 1) & ~((u64)root->sectorsize - 1); |
| |
| end_of_last_block = start_pos + num_bytes - 1; |
| err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block); |
| if (err) |
| return err; |
| |
| for (i = 0; i < num_pages; i++) { |
| struct page *p = pages[i]; |
| SetPageUptodate(p); |
| ClearPageChecked(p); |
| set_page_dirty(p); |
| } |
| 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 err; |
| } |
| |
| /* |
| * this drops all the extents in the cache that intersect the range |
| * [start, end]. Existing extents are split as required. |
| */ |
| int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, |
| int skip_pinned) |
| { |
| struct extent_map *em; |
| struct extent_map *split = NULL; |
| struct extent_map *split2 = NULL; |
| struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| u64 len = end - start + 1; |
| int ret; |
| int testend = 1; |
| unsigned long flags; |
| int compressed = 0; |
| |
| WARN_ON(end < start); |
| if (end == (u64)-1) { |
| len = (u64)-1; |
| testend = 0; |
| } |
| while (1) { |
| if (!split) |
| split = alloc_extent_map(GFP_NOFS); |
| if (!split2) |
| split2 = alloc_extent_map(GFP_NOFS); |
| |
| write_lock(&em_tree->lock); |
| em = lookup_extent_mapping(em_tree, start, len); |
| if (!em) { |
| write_unlock(&em_tree->lock); |
| break; |
| } |
| flags = em->flags; |
| if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) { |
| if (testend && em->start + em->len >= start + len) { |
| free_extent_map(em); |
| write_unlock(&em_tree->lock); |
| break; |
| } |
| start = em->start + em->len; |
| if (testend) |
| len = start + len - (em->start + em->len); |
| free_extent_map(em); |
| write_unlock(&em_tree->lock); |
| continue; |
| } |
| compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); |
| clear_bit(EXTENT_FLAG_PINNED, &em->flags); |
| remove_extent_mapping(em_tree, em); |
| |
| if (em->block_start < EXTENT_MAP_LAST_BYTE && |
| em->start < start) { |
| split->start = em->start; |
| split->len = start - em->start; |
| split->orig_start = em->orig_start; |
| split->block_start = em->block_start; |
| |
| if (compressed) |
| split->block_len = em->block_len; |
| else |
| split->block_len = split->len; |
| |
| split->bdev = em->bdev; |
| split->flags = flags; |
| ret = add_extent_mapping(em_tree, split); |
| BUG_ON(ret); |
| free_extent_map(split); |
| split = split2; |
| split2 = NULL; |
| } |
| if (em->block_start < EXTENT_MAP_LAST_BYTE && |
| testend && em->start + em->len > start + len) { |
| u64 diff = start + len - em->start; |
| |
| split->start = start + len; |
| split->len = em->start + em->len - (start + len); |
| split->bdev = em->bdev; |
| split->flags = flags; |
| |
| if (compressed) { |
| split->block_len = em->block_len; |
| split->block_start = em->block_start; |
| split->orig_start = em->orig_start; |
| } else { |
| split->block_len = split->len; |
| split->block_start = em->block_start + diff; |
| split->orig_start = split->start; |
| } |
| |
| ret = add_extent_mapping(em_tree, split); |
| BUG_ON(ret); |
| free_extent_map(split); |
| split = NULL; |
| } |
| write_unlock(&em_tree->lock); |
| |
| /* once for us */ |
| free_extent_map(em); |
| /* once for the tree*/ |
| free_extent_map(em); |
| } |
| if (split) |
| free_extent_map(split); |
| if (split2) |
| free_extent_map(split2); |
| return 0; |
| } |
| |
| /* |
| * this is very complex, but the basic idea is to drop all extents |
| * in the range start - end. hint_block is filled in with a block number |
| * that would be a good hint to the block allocator for this file. |
| * |
| * If an extent intersects the range but is not entirely inside the range |
| * it is either truncated or split. Anything entirely inside the range |
| * is deleted from the tree. |
| */ |
| int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode, |
| u64 start, u64 end, u64 *hint_byte, int drop_cache) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_buffer *leaf; |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| struct btrfs_key new_key; |
| u64 search_start = start; |
| u64 disk_bytenr = 0; |
| u64 num_bytes = 0; |
| u64 extent_offset = 0; |
| u64 extent_end = 0; |
| int del_nr = 0; |
| int del_slot = 0; |
| int extent_type; |
| int recow; |
| int ret; |
| |
| if (drop_cache) |
| btrfs_drop_extent_cache(inode, start, end - 1, 0); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| while (1) { |
| recow = 0; |
| ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, |
| search_start, -1); |
| if (ret < 0) |
| break; |
| if (ret > 0 && path->slots[0] > 0 && search_start == start) { |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); |
| if (key.objectid == inode->i_ino && |
| key.type == BTRFS_EXTENT_DATA_KEY) |
| path->slots[0]--; |
| } |
| ret = 0; |
| next_slot: |
| leaf = path->nodes[0]; |
| if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
| BUG_ON(del_nr > 0); |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) |
| break; |
| if (ret > 0) { |
| ret = 0; |
| break; |
| } |
| leaf = path->nodes[0]; |
| recow = 1; |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (key.objectid > inode->i_ino || |
| key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end) |
| break; |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| extent_type = btrfs_file_extent_type(leaf, fi); |
| |
| if (extent_type == BTRFS_FILE_EXTENT_REG || |
| extent_type == BTRFS_FILE_EXTENT_PREALLOC) { |
| disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
| extent_offset = btrfs_file_extent_offset(leaf, fi); |
| extent_end = key.offset + |
| btrfs_file_extent_num_bytes(leaf, fi); |
| } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| extent_end = key.offset + |
| btrfs_file_extent_inline_len(leaf, fi); |
| } else { |
| WARN_ON(1); |
| extent_end = search_start; |
| } |
| |
| if (extent_end <= search_start) { |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| search_start = max(key.offset, start); |
| if (recow) { |
| btrfs_release_path(root, path); |
| continue; |
| } |
| |
| /* |
| * | - range to drop - | |
| * | -------- extent -------- | |
| */ |
| if (start > key.offset && end < extent_end) { |
| BUG_ON(del_nr > 0); |
| BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE); |
| |
| memcpy(&new_key, &key, sizeof(new_key)); |
| new_key.offset = start; |
| ret = btrfs_duplicate_item(trans, root, path, |
| &new_key); |
| if (ret == -EAGAIN) { |
| btrfs_release_path(root, path); |
| continue; |
| } |
| if (ret < 0) |
| break; |
| |
| leaf = path->nodes[0]; |
| fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| start - key.offset); |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| |
| extent_offset += start - key.offset; |
| btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - start); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| if (disk_bytenr > 0) { |
| ret = btrfs_inc_extent_ref(trans, root, |
| disk_bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| new_key.objectid, |
| start - extent_offset); |
| BUG_ON(ret); |
| *hint_byte = disk_bytenr; |
| } |
| key.offset = start; |
| } |
| /* |
| * | ---- range to drop ----- | |
| * | -------- extent -------- | |
| */ |
| if (start <= key.offset && end < extent_end) { |
| BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE); |
| |
| memcpy(&new_key, &key, sizeof(new_key)); |
| new_key.offset = end; |
| btrfs_set_item_key_safe(trans, root, path, &new_key); |
| |
| extent_offset += end - key.offset; |
| btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - end); |
| btrfs_mark_buffer_dirty(leaf); |
| if (disk_bytenr > 0) { |
| inode_sub_bytes(inode, end - key.offset); |
| *hint_byte = disk_bytenr; |
| } |
| break; |
| } |
| |
| search_start = extent_end; |
| /* |
| * | ---- range to drop ----- | |
| * | -------- extent -------- | |
| */ |
| if (start > key.offset && end >= extent_end) { |
| BUG_ON(del_nr > 0); |
| BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE); |
| |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| start - key.offset); |
| btrfs_mark_buffer_dirty(leaf); |
| if (disk_bytenr > 0) { |
| inode_sub_bytes(inode, extent_end - start); |
| *hint_byte = disk_bytenr; |
| } |
| if (end == extent_end) |
| break; |
| |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| /* |
| * | ---- range to drop ----- | |
| * | ------ extent ------ | |
| */ |
| if (start <= key.offset && end >= extent_end) { |
| if (del_nr == 0) { |
| del_slot = path->slots[0]; |
| del_nr = 1; |
| } else { |
| BUG_ON(del_slot + del_nr != path->slots[0]); |
| del_nr++; |
| } |
| |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| inode_sub_bytes(inode, |
| extent_end - key.offset); |
| extent_end = ALIGN(extent_end, |
| root->sectorsize); |
| } else if (disk_bytenr > 0) { |
| ret = btrfs_free_extent(trans, root, |
| disk_bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| key.objectid, key.offset - |
| extent_offset); |
| BUG_ON(ret); |
| inode_sub_bytes(inode, |
| extent_end - key.offset); |
| *hint_byte = disk_bytenr; |
| } |
| |
| if (end == extent_end) |
| break; |
| |
| if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) { |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| ret = btrfs_del_items(trans, root, path, del_slot, |
| del_nr); |
| BUG_ON(ret); |
| |
| del_nr = 0; |
| del_slot = 0; |
| |
| btrfs_release_path(root, path); |
| continue; |
| } |
| |
| BUG_ON(1); |
| } |
| |
| if (del_nr > 0) { |
| ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| BUG_ON(ret); |
| } |
| |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| static int extent_mergeable(struct extent_buffer *leaf, int slot, |
| u64 objectid, u64 bytenr, u64 orig_offset, |
| u64 *start, u64 *end) |
| { |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| u64 extent_end; |
| |
| if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
| return 0; |
| |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY) |
| return 0; |
| |
| fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
| if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || |
| btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr || |
| btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset || |
| btrfs_file_extent_compression(leaf, fi) || |
| btrfs_file_extent_encryption(leaf, fi) || |
| btrfs_file_extent_other_encoding(leaf, fi)) |
| return 0; |
| |
| extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
| if ((*start && *start != key.offset) || (*end && *end != extent_end)) |
| return 0; |
| |
| *start = key.offset; |
| *end = extent_end; |
| return 1; |
| } |
| |
| /* |
| * Mark extent in the range start - end as written. |
| * |
| * This changes extent type from 'pre-allocated' to 'regular'. If only |
| * part of extent is marked as written, the extent will be split into |
| * two or three. |
| */ |
| int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, |
| struct inode *inode, u64 start, u64 end) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_buffer *leaf; |
| struct btrfs_path *path; |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| struct btrfs_key new_key; |
| u64 bytenr; |
| u64 num_bytes; |
| u64 extent_end; |
| u64 orig_offset; |
| u64 other_start; |
| u64 other_end; |
| u64 split; |
| int del_nr = 0; |
| int del_slot = 0; |
| int recow; |
| int ret; |
| |
| btrfs_drop_extent_cache(inode, start, end - 1, 0); |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| again: |
| recow = 0; |
| split = start; |
| key.objectid = inode->i_ino; |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| key.offset = split; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0 && path->slots[0] > 0) |
| path->slots[0]--; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| BUG_ON(key.objectid != inode->i_ino || |
| key.type != BTRFS_EXTENT_DATA_KEY); |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| BUG_ON(btrfs_file_extent_type(leaf, fi) != |
| BTRFS_FILE_EXTENT_PREALLOC); |
| extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
| BUG_ON(key.offset > start || extent_end < end); |
| |
| bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
| orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi); |
| memcpy(&new_key, &key, sizeof(new_key)); |
| |
| if (start == key.offset && end < extent_end) { |
| other_start = 0; |
| other_end = start; |
| if (extent_mergeable(leaf, path->slots[0] - 1, |
| inode->i_ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| new_key.offset = end; |
| btrfs_set_item_key_safe(trans, root, path, &new_key); |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - end); |
| btrfs_set_file_extent_offset(leaf, fi, |
| end - orig_offset); |
| fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| end - other_start); |
| btrfs_mark_buffer_dirty(leaf); |
| goto out; |
| } |
| } |
| |
| if (start > key.offset && end == extent_end) { |
| other_start = end; |
| other_end = 0; |
| if (extent_mergeable(leaf, path->slots[0] + 1, |
| inode->i_ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| start - key.offset); |
| path->slots[0]++; |
| new_key.offset = start; |
| btrfs_set_item_key_safe(trans, root, path, &new_key); |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| other_end - start); |
| btrfs_set_file_extent_offset(leaf, fi, |
| start - orig_offset); |
| btrfs_mark_buffer_dirty(leaf); |
| goto out; |
| } |
| } |
| |
| while (start > key.offset || end < extent_end) { |
| if (key.offset == start) |
| split = end; |
| |
| new_key.offset = split; |
| ret = btrfs_duplicate_item(trans, root, path, &new_key); |
| if (ret == -EAGAIN) { |
| btrfs_release_path(root, path); |
| goto again; |
| } |
| BUG_ON(ret < 0); |
| |
| leaf = path->nodes[0]; |
| fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| split - key.offset); |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| |
| btrfs_set_file_extent_offset(leaf, fi, split - orig_offset); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - split); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| inode->i_ino, orig_offset); |
| BUG_ON(ret); |
| |
| if (split == start) { |
| key.offset = start; |
| } else { |
| BUG_ON(start != key.offset); |
| path->slots[0]--; |
| extent_end = end; |
| } |
| recow = 1; |
| } |
| |
| other_start = end; |
| other_end = 0; |
| if (extent_mergeable(leaf, path->slots[0] + 1, |
| inode->i_ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| if (recow) { |
| btrfs_release_path(root, path); |
| goto again; |
| } |
| extent_end = other_end; |
| del_slot = path->slots[0] + 1; |
| del_nr++; |
| ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
| 0, root->root_key.objectid, |
| inode->i_ino, orig_offset); |
| BUG_ON(ret); |
| } |
| other_start = 0; |
| other_end = start; |
| if (extent_mergeable(leaf, path->slots[0] - 1, |
| inode->i_ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| if (recow) { |
| btrfs_release_path(root, path); |
| goto again; |
| } |
| key.offset = other_start; |
| del_slot = path->slots[0]; |
| del_nr++; |
| ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
| 0, root->root_key.objectid, |
| inode->i_ino, orig_offset); |
| BUG_ON(ret); |
| } |
| if (del_nr == 0) { |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_type(leaf, fi, |
| BTRFS_FILE_EXTENT_REG); |
| btrfs_mark_buffer_dirty(leaf); |
| } else { |
| fi = btrfs_item_ptr(leaf, del_slot - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_type(leaf, fi, |
| BTRFS_FILE_EXTENT_REG); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - key.offset); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| BUG_ON(ret); |
| } |
| out: |
| btrfs_free_path(path); |
| 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. |
| */ |
| static noinline int prepare_pages(struct btrfs_root *root, struct file *file, |
| struct page **pages, size_t num_pages, |
| loff_t pos, unsigned long first_index, |
| unsigned long last_index, size_t write_bytes) |
| { |
| int i; |
| unsigned long index = pos >> PAGE_CACHE_SHIFT; |
| struct inode *inode = fdentry(file)->d_inode; |
| int err = 0; |
| u64 start_pos; |
| u64 last_pos; |
| |
| start_pos = pos & ~((u64)root->sectorsize - 1); |
| last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT; |
| |
| if (start_pos > inode->i_size) { |
| err = btrfs_cont_expand(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]) { |
| err = -ENOMEM; |
| BUG_ON(1); |
| } |
| wait_on_page_writeback(pages[i]); |
| } |
| if (start_pos < inode->i_size) { |
| struct btrfs_ordered_extent *ordered; |
| lock_extent(&BTRFS_I(inode)->io_tree, |
| start_pos, last_pos - 1, GFP_NOFS); |
| ordered = btrfs_lookup_first_ordered_extent(inode, |
| last_pos - 1); |
| if (ordered && |
| ordered->file_offset + ordered->len > start_pos && |
| ordered->file_offset < last_pos) { |
| btrfs_put_ordered_extent(ordered); |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| start_pos, last_pos - 1, GFP_NOFS); |
| for (i = 0; i < num_pages; i++) { |
| unlock_page(pages[i]); |
| page_cache_release(pages[i]); |
| } |
| btrfs_wait_ordered_range(inode, start_pos, |
| last_pos - start_pos); |
| goto again; |
| } |
| if (ordered) |
| btrfs_put_ordered_extent(ordered); |
| |
| clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos, |
| last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, |
| GFP_NOFS); |
| unlock_extent(&BTRFS_I(inode)->io_tree, |
| start_pos, last_pos - 1, GFP_NOFS); |
| } |
| for (i = 0; i < num_pages; i++) { |
| clear_page_dirty_for_io(pages[i]); |
| set_page_extent_mapped(pages[i]); |
| WARN_ON(!PageLocked(pages[i])); |
| } |
| return 0; |
| } |
| |
| static ssize_t btrfs_file_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| loff_t pos; |
| loff_t start_pos; |
| ssize_t num_written = 0; |
| ssize_t err = 0; |
| 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; |
| |
| will_write = ((file->f_flags & O_SYNC) || 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); |
| |
| 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; |
| |
| file_update_time(file); |
| |
| 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; |
| |
| /* |
| * 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 + count) & (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 (count > 0) { |
| size_t offset = pos & (PAGE_CACHE_SIZE - 1); |
| size_t write_bytes = min(count, nrptrs * |
| (size_t)PAGE_CACHE_SIZE - |
| offset); |
| size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> |
| PAGE_CACHE_SHIFT; |
| |
| WARN_ON(num_pages > nrptrs); |
| memset(pages, 0, sizeof(struct page *) * nrptrs); |
| |
| ret = btrfs_check_data_free_space(root, inode, write_bytes); |
| if (ret) |
| goto out; |
| |
| ret = prepare_pages(root, file, pages, num_pages, |
| pos, first_index, last_index, |
| write_bytes); |
| if (ret) { |
| btrfs_free_reserved_data_space(root, 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; |
| } |
| |
| 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); |
| goto out; |
| } |
| |
| if (will_write) { |
| filemap_fdatawrite_range(inode->i_mapping, pos, |
| pos + write_bytes - 1); |
| } else { |
| balance_dirty_pages_ratelimited_nr(inode->i_mapping, |
| num_pages); |
| if (num_pages < |
| (root->leafsize >> PAGE_CACHE_SHIFT) + 1) |
| btrfs_btree_balance_dirty(root, 1); |
| btrfs_throttle(root); |
| } |
| |
| buf += write_bytes; |
| count -= write_bytes; |
| pos += write_bytes; |
| num_written += write_bytes; |
| |
| cond_resched(); |
| } |
| 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]); |
| if (pinned[1]) |
| page_cache_release(pinned[1]); |
| *ppos = pos; |
| |
| /* |
| * we want to make sure fsync finds this change |
| * but we haven't joined a transaction running right now. |
| * |
| * Later on, someone is sure to update the inode and get the |
| * real transid recorded. |
| * |
| * We set last_trans now to the fs_info generation + 1, |
| * this will either be one more than the running transaction |
| * or the generation used for the next transaction if there isn't |
| * 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) |
| num_written = err; |
| |
| if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) { |
| trans = btrfs_start_transaction(root, 1); |
| ret = btrfs_log_dentry_safe(trans, root, |
| file->f_dentry); |
| 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) { |
| invalidate_mapping_pages(inode->i_mapping, |
| start_pos >> PAGE_CACHE_SHIFT, |
| (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT); |
| } |
| } |
| current->backing_dev_info = NULL; |
| return num_written ? num_written : err; |
| } |
| |
| int btrfs_release_file(struct inode *inode, struct file *filp) |
| { |
| /* |
| * ordered_data_close is set by settattr when we are about to truncate |
| * a file from a non-zero size to a zero size. This tries to |
| * flush down new bytes that may have been written if the |
| * application were using truncate to replace a file in place. |
| */ |
| if (BTRFS_I(inode)->ordered_data_close) { |
| BTRFS_I(inode)->ordered_data_close = 0; |
| btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode); |
| if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) |
| filemap_flush(inode->i_mapping); |
| } |
| if (filp->private_data) |
| btrfs_ioctl_trans_end(filp); |
| return 0; |
| } |
| |
| /* |
| * fsync call for both files and directories. This logs the inode into |
| * the tree log instead of forcing full commits whenever possible. |
| * |
| * It needs to call filemap_fdatawait so that all ordered extent updates are |
| * in the metadata btree are up to date for copying to the log. |
| * |
| * It drops the inode mutex before doing the tree log commit. This is an |
| * important optimization for directories because holding the mutex prevents |
| * new operations on the dir while we write to disk. |
| */ |
| int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync) |
| { |
| struct inode *inode = dentry->d_inode; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| int ret = 0; |
| struct btrfs_trans_handle *trans; |
| |
| |
| /* we wait first, since the writeback may change the inode */ |
| root->log_batch++; |
| /* the VFS called filemap_fdatawrite for us */ |
| btrfs_wait_ordered_range(inode, 0, (u64)-1); |
| root->log_batch++; |
| |
| /* |
| * check the transaction that last modified this inode |
| * and see if its already been committed |
| */ |
| if (!BTRFS_I(inode)->last_trans) |
| goto out; |
| |
| /* |
| * if the last transaction that changed this file was before |
| * the current transaction, we can bail out now without any |
| * syncing |
| */ |
| mutex_lock(&root->fs_info->trans_mutex); |
| if (BTRFS_I(inode)->last_trans <= |
| root->fs_info->last_trans_committed) { |
| BTRFS_I(inode)->last_trans = 0; |
| mutex_unlock(&root->fs_info->trans_mutex); |
| goto out; |
| } |
| mutex_unlock(&root->fs_info->trans_mutex); |
| |
| /* |
| * ok we haven't committed the transaction yet, lets do a commit |
| */ |
| if (file && file->private_data) |
| btrfs_ioctl_trans_end(file); |
| |
| trans = btrfs_start_transaction(root, 1); |
| if (!trans) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = btrfs_log_dentry_safe(trans, root, dentry); |
| if (ret < 0) |
| goto out; |
| |
| /* we've logged all the items and now have a consistent |
| * version of the file in the log. It is possible that |
| * someone will come in and modify the file, but that's |
| * fine because the log is consistent on disk, and we |
| * have references to all of the file's extents |
| * |
| * It is possible that someone will come in and log the |
| * file again, but that will end up using the synchronization |
| * inside btrfs_sync_log to keep things safe. |
| */ |
| mutex_unlock(&dentry->d_inode->i_mutex); |
| |
| if (ret != BTRFS_NO_LOG_SYNC) { |
| if (ret > 0) { |
| ret = btrfs_commit_transaction(trans, root); |
| } else { |
| ret = btrfs_sync_log(trans, root); |
| if (ret == 0) |
| ret = btrfs_end_transaction(trans, root); |
| else |
| ret = btrfs_commit_transaction(trans, root); |
| } |
| } else { |
| ret = btrfs_end_transaction(trans, root); |
| } |
| mutex_lock(&dentry->d_inode->i_mutex); |
| out: |
| return ret > 0 ? -EIO : ret; |
| } |
| |
| static const struct vm_operations_struct btrfs_file_vm_ops = { |
| .fault = filemap_fault, |
| .page_mkwrite = btrfs_page_mkwrite, |
| }; |
| |
| static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) |
| { |
| vma->vm_ops = &btrfs_file_vm_ops; |
| file_accessed(filp); |
| return 0; |
| } |
| |
| const struct file_operations btrfs_file_operations = { |
| .llseek = generic_file_llseek, |
| .read = do_sync_read, |
| .aio_read = generic_file_aio_read, |
| .splice_read = generic_file_splice_read, |
| .write = btrfs_file_write, |
| .mmap = btrfs_file_mmap, |
| .open = generic_file_open, |
| .release = btrfs_release_file, |
| .fsync = btrfs_sync_file, |
| .unlocked_ioctl = btrfs_ioctl, |
| #ifdef CONFIG_COMPAT |
| .compat_ioctl = btrfs_ioctl, |
| #endif |
| }; |