| /* |
| * 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/falloc.h> |
| #include <linux/swap.h> |
| #include <linux/writeback.h> |
| #include <linux/compat.h> |
| #include <linux/slab.h> |
| #include <linux/btrfs.h> |
| #include <linux/uio.h> |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "btrfs_inode.h" |
| #include "print-tree.h" |
| #include "tree-log.h" |
| #include "locking.h" |
| #include "volumes.h" |
| #include "qgroup.h" |
| #include "compression.h" |
| |
| static struct kmem_cache *btrfs_inode_defrag_cachep; |
| /* |
| * when auto defrag is enabled we |
| * queue up these defrag structs to remember which |
| * inodes need defragging passes |
| */ |
| struct inode_defrag { |
| struct rb_node rb_node; |
| /* objectid */ |
| u64 ino; |
| /* |
| * transid where the defrag was added, we search for |
| * extents newer than this |
| */ |
| u64 transid; |
| |
| /* root objectid */ |
| u64 root; |
| |
| /* last offset we were able to defrag */ |
| u64 last_offset; |
| |
| /* if we've wrapped around back to zero once already */ |
| int cycled; |
| }; |
| |
| static int __compare_inode_defrag(struct inode_defrag *defrag1, |
| struct inode_defrag *defrag2) |
| { |
| if (defrag1->root > defrag2->root) |
| return 1; |
| else if (defrag1->root < defrag2->root) |
| return -1; |
| else if (defrag1->ino > defrag2->ino) |
| return 1; |
| else if (defrag1->ino < defrag2->ino) |
| return -1; |
| else |
| return 0; |
| } |
| |
| /* pop a record for an inode into the defrag tree. The lock |
| * must be held already |
| * |
| * If you're inserting a record for an older transid than an |
| * existing record, the transid already in the tree is lowered |
| * |
| * If an existing record is found the defrag item you |
| * pass in is freed |
| */ |
| static int __btrfs_add_inode_defrag(struct btrfs_inode *inode, |
| struct inode_defrag *defrag) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); |
| struct inode_defrag *entry; |
| struct rb_node **p; |
| struct rb_node *parent = NULL; |
| int ret; |
| |
| p = &fs_info->defrag_inodes.rb_node; |
| while (*p) { |
| parent = *p; |
| entry = rb_entry(parent, struct inode_defrag, rb_node); |
| |
| ret = __compare_inode_defrag(defrag, entry); |
| if (ret < 0) |
| p = &parent->rb_left; |
| else if (ret > 0) |
| p = &parent->rb_right; |
| else { |
| /* if we're reinserting an entry for |
| * an old defrag run, make sure to |
| * lower the transid of our existing record |
| */ |
| if (defrag->transid < entry->transid) |
| entry->transid = defrag->transid; |
| if (defrag->last_offset > entry->last_offset) |
| entry->last_offset = defrag->last_offset; |
| return -EEXIST; |
| } |
| } |
| set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags); |
| rb_link_node(&defrag->rb_node, parent, p); |
| rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes); |
| return 0; |
| } |
| |
| static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info) |
| { |
| if (!btrfs_test_opt(fs_info, AUTO_DEFRAG)) |
| return 0; |
| |
| if (btrfs_fs_closing(fs_info)) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* |
| * insert a defrag record for this inode if auto defrag is |
| * enabled |
| */ |
| int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, |
| struct btrfs_inode *inode) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); |
| struct btrfs_root *root = inode->root; |
| struct inode_defrag *defrag; |
| u64 transid; |
| int ret; |
| |
| if (!__need_auto_defrag(fs_info)) |
| return 0; |
| |
| if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) |
| return 0; |
| |
| if (trans) |
| transid = trans->transid; |
| else |
| transid = inode->root->last_trans; |
| |
| defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS); |
| if (!defrag) |
| return -ENOMEM; |
| |
| defrag->ino = btrfs_ino(inode); |
| defrag->transid = transid; |
| defrag->root = root->root_key.objectid; |
| |
| spin_lock(&fs_info->defrag_inodes_lock); |
| if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) { |
| /* |
| * If we set IN_DEFRAG flag and evict the inode from memory, |
| * and then re-read this inode, this new inode doesn't have |
| * IN_DEFRAG flag. At the case, we may find the existed defrag. |
| */ |
| ret = __btrfs_add_inode_defrag(inode, defrag); |
| if (ret) |
| kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| } else { |
| kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| } |
| spin_unlock(&fs_info->defrag_inodes_lock); |
| return 0; |
| } |
| |
| /* |
| * Requeue the defrag object. If there is a defrag object that points to |
| * the same inode in the tree, we will merge them together (by |
| * __btrfs_add_inode_defrag()) and free the one that we want to requeue. |
| */ |
| static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode, |
| struct inode_defrag *defrag) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); |
| int ret; |
| |
| if (!__need_auto_defrag(fs_info)) |
| goto out; |
| |
| /* |
| * Here we don't check the IN_DEFRAG flag, because we need merge |
| * them together. |
| */ |
| spin_lock(&fs_info->defrag_inodes_lock); |
| ret = __btrfs_add_inode_defrag(inode, defrag); |
| spin_unlock(&fs_info->defrag_inodes_lock); |
| if (ret) |
| goto out; |
| return; |
| out: |
| kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| } |
| |
| /* |
| * pick the defragable inode that we want, if it doesn't exist, we will get |
| * the next one. |
| */ |
| static struct inode_defrag * |
| btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino) |
| { |
| struct inode_defrag *entry = NULL; |
| struct inode_defrag tmp; |
| struct rb_node *p; |
| struct rb_node *parent = NULL; |
| int ret; |
| |
| tmp.ino = ino; |
| tmp.root = root; |
| |
| spin_lock(&fs_info->defrag_inodes_lock); |
| p = fs_info->defrag_inodes.rb_node; |
| while (p) { |
| parent = p; |
| entry = rb_entry(parent, struct inode_defrag, rb_node); |
| |
| ret = __compare_inode_defrag(&tmp, entry); |
| if (ret < 0) |
| p = parent->rb_left; |
| else if (ret > 0) |
| p = parent->rb_right; |
| else |
| goto out; |
| } |
| |
| if (parent && __compare_inode_defrag(&tmp, entry) > 0) { |
| parent = rb_next(parent); |
| if (parent) |
| entry = rb_entry(parent, struct inode_defrag, rb_node); |
| else |
| entry = NULL; |
| } |
| out: |
| if (entry) |
| rb_erase(parent, &fs_info->defrag_inodes); |
| spin_unlock(&fs_info->defrag_inodes_lock); |
| return entry; |
| } |
| |
| void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info) |
| { |
| struct inode_defrag *defrag; |
| struct rb_node *node; |
| |
| spin_lock(&fs_info->defrag_inodes_lock); |
| node = rb_first(&fs_info->defrag_inodes); |
| while (node) { |
| rb_erase(node, &fs_info->defrag_inodes); |
| defrag = rb_entry(node, struct inode_defrag, rb_node); |
| kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| |
| cond_resched_lock(&fs_info->defrag_inodes_lock); |
| |
| node = rb_first(&fs_info->defrag_inodes); |
| } |
| spin_unlock(&fs_info->defrag_inodes_lock); |
| } |
| |
| #define BTRFS_DEFRAG_BATCH 1024 |
| |
| static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info, |
| struct inode_defrag *defrag) |
| { |
| struct btrfs_root *inode_root; |
| struct inode *inode; |
| struct btrfs_key key; |
| struct btrfs_ioctl_defrag_range_args range; |
| int num_defrag; |
| int index; |
| int ret; |
| |
| /* get the inode */ |
| key.objectid = defrag->root; |
| key.type = BTRFS_ROOT_ITEM_KEY; |
| key.offset = (u64)-1; |
| |
| index = srcu_read_lock(&fs_info->subvol_srcu); |
| |
| inode_root = btrfs_read_fs_root_no_name(fs_info, &key); |
| if (IS_ERR(inode_root)) { |
| ret = PTR_ERR(inode_root); |
| goto cleanup; |
| } |
| |
| key.objectid = defrag->ino; |
| key.type = BTRFS_INODE_ITEM_KEY; |
| key.offset = 0; |
| inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL); |
| if (IS_ERR(inode)) { |
| ret = PTR_ERR(inode); |
| goto cleanup; |
| } |
| srcu_read_unlock(&fs_info->subvol_srcu, index); |
| |
| /* do a chunk of defrag */ |
| clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); |
| memset(&range, 0, sizeof(range)); |
| range.len = (u64)-1; |
| range.start = defrag->last_offset; |
| |
| sb_start_write(fs_info->sb); |
| num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid, |
| BTRFS_DEFRAG_BATCH); |
| sb_end_write(fs_info->sb); |
| /* |
| * if we filled the whole defrag batch, there |
| * must be more work to do. Queue this defrag |
| * again |
| */ |
| if (num_defrag == BTRFS_DEFRAG_BATCH) { |
| defrag->last_offset = range.start; |
| btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag); |
| } else if (defrag->last_offset && !defrag->cycled) { |
| /* |
| * we didn't fill our defrag batch, but |
| * we didn't start at zero. Make sure we loop |
| * around to the start of the file. |
| */ |
| defrag->last_offset = 0; |
| defrag->cycled = 1; |
| btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag); |
| } else { |
| kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| } |
| |
| iput(inode); |
| return 0; |
| cleanup: |
| srcu_read_unlock(&fs_info->subvol_srcu, index); |
| kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| return ret; |
| } |
| |
| /* |
| * run through the list of inodes in the FS that need |
| * defragging |
| */ |
| int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) |
| { |
| struct inode_defrag *defrag; |
| u64 first_ino = 0; |
| u64 root_objectid = 0; |
| |
| atomic_inc(&fs_info->defrag_running); |
| while (1) { |
| /* Pause the auto defragger. */ |
| if (test_bit(BTRFS_FS_STATE_REMOUNTING, |
| &fs_info->fs_state)) |
| break; |
| |
| if (!__need_auto_defrag(fs_info)) |
| break; |
| |
| /* find an inode to defrag */ |
| defrag = btrfs_pick_defrag_inode(fs_info, root_objectid, |
| first_ino); |
| if (!defrag) { |
| if (root_objectid || first_ino) { |
| root_objectid = 0; |
| first_ino = 0; |
| continue; |
| } else { |
| break; |
| } |
| } |
| |
| first_ino = defrag->ino + 1; |
| root_objectid = defrag->root; |
| |
| __btrfs_run_defrag_inode(fs_info, defrag); |
| } |
| atomic_dec(&fs_info->defrag_running); |
| |
| /* |
| * during unmount, we use the transaction_wait queue to |
| * wait for the defragger to stop |
| */ |
| wake_up(&fs_info->transaction_wait); |
| return 0; |
| } |
| |
| /* 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, 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_SIZE - 1); |
| |
| while (write_bytes > 0) { |
| size_t count = min_t(size_t, |
| PAGE_SIZE - offset, write_bytes); |
| struct page *page = prepared_pages[pg]; |
| /* |
| * Copy data from userspace to the current page |
| */ |
| copied = iov_iter_copy_from_user_atomic(page, i, offset, count); |
| |
| /* 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_write_iter to fault page */ |
| if (unlikely(copied == 0)) |
| break; |
| |
| if (copied < PAGE_SIZE - offset) { |
| offset += copied; |
| } else { |
| pg++; |
| offset = 0; |
| } |
| } |
| return total_copied; |
| } |
| |
| /* |
| * unlocks pages after btrfs_file_write is done with them |
| */ |
| static void btrfs_drop_pages(struct page **pages, size_t num_pages) |
| { |
| size_t i; |
| for (i = 0; i < num_pages; i++) { |
| /* page checked is some magic around finding pages that |
| * have been modified without going through btrfs_set_page_dirty |
| * clear it here. There should be no need to mark the pages |
| * accessed as prepare_pages should have marked them accessed |
| * in prepare_pages via find_or_create_page() |
| */ |
| ClearPageChecked(pages[i]); |
| unlock_page(pages[i]); |
| put_page(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. |
| */ |
| int btrfs_dirty_pages(struct inode *inode, struct page **pages, |
| size_t num_pages, loff_t pos, size_t write_bytes, |
| struct extent_state **cached) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| int err = 0; |
| int i; |
| 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) fs_info->sectorsize - 1); |
| num_bytes = round_up(write_bytes + pos - start_pos, |
| fs_info->sectorsize); |
| |
| end_of_last_block = start_pos + num_bytes - 1; |
| err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block, |
| cached, 0); |
| if (err) |
| return err; |
| |
| for (i = 0; i < num_pages; i++) { |
| struct page *p = pages[i]; |
| SetPageUptodate(p); |
| ClearPageChecked(p); |
| set_page_dirty(p); |
| } |
| |
| /* |
| * 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); |
| return 0; |
| } |
| |
| /* |
| * this drops all the extents in the cache that intersect the range |
| * [start, end]. Existing extents are split as required. |
| */ |
| void btrfs_drop_extent_cache(struct btrfs_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 = &inode->extent_tree; |
| u64 len = end - start + 1; |
| u64 gen; |
| int ret; |
| int testend = 1; |
| unsigned long flags; |
| int compressed = 0; |
| bool modified; |
| |
| WARN_ON(end < start); |
| if (end == (u64)-1) { |
| len = (u64)-1; |
| testend = 0; |
| } |
| while (1) { |
| int no_splits = 0; |
| |
| modified = false; |
| if (!split) |
| split = alloc_extent_map(); |
| if (!split2) |
| split2 = alloc_extent_map(); |
| if (!split || !split2) |
| no_splits = 1; |
| |
| write_lock(&em_tree->lock); |
| em = lookup_extent_mapping(em_tree, start, len); |
| if (!em) { |
| write_unlock(&em_tree->lock); |
| break; |
| } |
| flags = em->flags; |
| gen = em->generation; |
| 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); |
| clear_bit(EXTENT_FLAG_LOGGING, &flags); |
| modified = !list_empty(&em->list); |
| if (no_splits) |
| goto next; |
| |
| if (em->start < start) { |
| split->start = em->start; |
| split->len = start - em->start; |
| |
| if (em->block_start < EXTENT_MAP_LAST_BYTE) { |
| 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->orig_block_len = max(split->block_len, |
| em->orig_block_len); |
| split->ram_bytes = em->ram_bytes; |
| } else { |
| split->orig_start = split->start; |
| split->block_len = 0; |
| split->block_start = em->block_start; |
| split->orig_block_len = 0; |
| split->ram_bytes = split->len; |
| } |
| |
| split->generation = gen; |
| split->bdev = em->bdev; |
| split->flags = flags; |
| split->compress_type = em->compress_type; |
| replace_extent_mapping(em_tree, em, split, modified); |
| free_extent_map(split); |
| split = split2; |
| split2 = NULL; |
| } |
| if (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; |
| split->compress_type = em->compress_type; |
| split->generation = gen; |
| |
| if (em->block_start < EXTENT_MAP_LAST_BYTE) { |
| split->orig_block_len = max(em->block_len, |
| em->orig_block_len); |
| |
| split->ram_bytes = em->ram_bytes; |
| 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 = em->orig_start; |
| } |
| } else { |
| split->ram_bytes = split->len; |
| split->orig_start = split->start; |
| split->block_len = 0; |
| split->block_start = em->block_start; |
| split->orig_block_len = 0; |
| } |
| |
| if (extent_map_in_tree(em)) { |
| replace_extent_mapping(em_tree, em, split, |
| modified); |
| } else { |
| ret = add_extent_mapping(em_tree, split, |
| modified); |
| ASSERT(ret == 0); /* Logic error */ |
| } |
| free_extent_map(split); |
| split = NULL; |
| } |
| next: |
| if (extent_map_in_tree(em)) |
| remove_extent_mapping(em_tree, em); |
| 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); |
| } |
| |
| /* |
| * 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 btrfs_root *root, struct inode *inode, |
| struct btrfs_path *path, u64 start, u64 end, |
| u64 *drop_end, int drop_cache, |
| int replace_extent, |
| u32 extent_item_size, |
| int *key_inserted) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct extent_buffer *leaf; |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| struct btrfs_key new_key; |
| u64 ino = btrfs_ino(BTRFS_I(inode)); |
| u64 search_start = start; |
| u64 disk_bytenr = 0; |
| u64 num_bytes = 0; |
| u64 extent_offset = 0; |
| u64 extent_end = 0; |
| u64 last_end = start; |
| int del_nr = 0; |
| int del_slot = 0; |
| int extent_type; |
| int recow; |
| int ret; |
| int modify_tree = -1; |
| int update_refs; |
| int found = 0; |
| int leafs_visited = 0; |
| |
| if (drop_cache) |
| btrfs_drop_extent_cache(BTRFS_I(inode), start, end - 1, 0); |
| |
| if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent) |
| modify_tree = 0; |
| |
| update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || |
| root == fs_info->tree_root); |
| while (1) { |
| recow = 0; |
| ret = btrfs_lookup_file_extent(trans, root, path, ino, |
| search_start, modify_tree); |
| 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 == ino && |
| key.type == BTRFS_EXTENT_DATA_KEY) |
| path->slots[0]--; |
| } |
| ret = 0; |
| leafs_visited++; |
| 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; |
| } |
| leafs_visited++; |
| leaf = path->nodes[0]; |
| recow = 1; |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| |
| if (key.objectid > ino) |
| break; |
| if (WARN_ON_ONCE(key.objectid < ino) || |
| key.type < BTRFS_EXTENT_DATA_KEY) { |
| ASSERT(del_nr == 0); |
| path->slots[0]++; |
| goto next_slot; |
| } |
| if (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, |
| path->slots[0], fi); |
| } else { |
| /* can't happen */ |
| BUG(); |
| } |
| |
| /* |
| * Don't skip extent items representing 0 byte lengths. They |
| * used to be created (bug) if while punching holes we hit |
| * -ENOSPC condition. So if we find one here, just ensure we |
| * delete it, otherwise we would insert a new file extent item |
| * with the same key (offset) as that 0 bytes length file |
| * extent item in the call to setup_items_for_insert() later |
| * in this function. |
| */ |
| if (extent_end == key.offset && extent_end >= search_start) { |
| last_end = extent_end; |
| goto delete_extent_item; |
| } |
| |
| if (extent_end <= search_start) { |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| found = 1; |
| search_start = max(key.offset, start); |
| if (recow || !modify_tree) { |
| modify_tree = -1; |
| btrfs_release_path(path); |
| continue; |
| } |
| |
| /* |
| * | - range to drop - | |
| * | -------- extent -------- | |
| */ |
| if (start > key.offset && end < extent_end) { |
| BUG_ON(del_nr > 0); |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| ret = -EOPNOTSUPP; |
| break; |
| } |
| |
| 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(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 (update_refs && disk_bytenr > 0) { |
| ret = btrfs_inc_extent_ref(trans, fs_info, |
| disk_bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| new_key.objectid, |
| start - extent_offset); |
| BUG_ON(ret); /* -ENOMEM */ |
| } |
| key.offset = start; |
| } |
| /* |
| * From here on out we will have actually dropped something, so |
| * last_end can be updated. |
| */ |
| last_end = extent_end; |
| |
| /* |
| * | ---- range to drop ----- | |
| * | -------- extent -------- | |
| */ |
| if (start <= key.offset && end < extent_end) { |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| ret = -EOPNOTSUPP; |
| break; |
| } |
| |
| memcpy(&new_key, &key, sizeof(new_key)); |
| new_key.offset = end; |
| btrfs_set_item_key_safe(fs_info, 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 (update_refs && disk_bytenr > 0) |
| inode_sub_bytes(inode, end - key.offset); |
| break; |
| } |
| |
| search_start = extent_end; |
| /* |
| * | ---- range to drop ----- | |
| * | -------- extent -------- | |
| */ |
| if (start > key.offset && end >= extent_end) { |
| BUG_ON(del_nr > 0); |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| ret = -EOPNOTSUPP; |
| break; |
| } |
| |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| start - key.offset); |
| btrfs_mark_buffer_dirty(leaf); |
| if (update_refs && disk_bytenr > 0) |
| inode_sub_bytes(inode, extent_end - start); |
| if (end == extent_end) |
| break; |
| |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| /* |
| * | ---- range to drop ----- | |
| * | ------ extent ------ | |
| */ |
| if (start <= key.offset && end >= extent_end) { |
| delete_extent_item: |
| 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 (update_refs && |
| extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| inode_sub_bytes(inode, |
| extent_end - key.offset); |
| extent_end = ALIGN(extent_end, |
| fs_info->sectorsize); |
| } else if (update_refs && disk_bytenr > 0) { |
| ret = btrfs_free_extent(trans, fs_info, |
| disk_bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| key.objectid, key.offset - |
| extent_offset); |
| BUG_ON(ret); /* -ENOMEM */ |
| inode_sub_bytes(inode, |
| extent_end - key.offset); |
| } |
| |
| 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); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| |
| del_nr = 0; |
| del_slot = 0; |
| |
| btrfs_release_path(path); |
| continue; |
| } |
| |
| BUG_ON(1); |
| } |
| |
| if (!ret && del_nr > 0) { |
| /* |
| * Set path->slots[0] to first slot, so that after the delete |
| * if items are move off from our leaf to its immediate left or |
| * right neighbor leafs, we end up with a correct and adjusted |
| * path->slots[0] for our insertion (if replace_extent != 0). |
| */ |
| path->slots[0] = del_slot; |
| ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| if (ret) |
| btrfs_abort_transaction(trans, ret); |
| } |
| |
| leaf = path->nodes[0]; |
| /* |
| * If btrfs_del_items() was called, it might have deleted a leaf, in |
| * which case it unlocked our path, so check path->locks[0] matches a |
| * write lock. |
| */ |
| if (!ret && replace_extent && leafs_visited == 1 && |
| (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING || |
| path->locks[0] == BTRFS_WRITE_LOCK) && |
| btrfs_leaf_free_space(fs_info, leaf) >= |
| sizeof(struct btrfs_item) + extent_item_size) { |
| |
| key.objectid = ino; |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| key.offset = start; |
| if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) { |
| struct btrfs_key slot_key; |
| |
| btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]); |
| if (btrfs_comp_cpu_keys(&key, &slot_key) > 0) |
| path->slots[0]++; |
| } |
| setup_items_for_insert(root, path, &key, |
| &extent_item_size, |
| extent_item_size, |
| sizeof(struct btrfs_item) + |
| extent_item_size, 1); |
| *key_inserted = 1; |
| } |
| |
| if (!replace_extent || !(*key_inserted)) |
| btrfs_release_path(path); |
| if (drop_end) |
| *drop_end = found ? min(end, last_end) : end; |
| return ret; |
| } |
| |
| int btrfs_drop_extents(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct inode *inode, u64 start, |
| u64 end, int drop_cache) |
| { |
| struct btrfs_path *path; |
| int ret; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL, |
| drop_cache, 0, 0, NULL); |
| 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 btrfs_inode *inode, u64 start, u64 end) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); |
| struct btrfs_root *root = 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; |
| u64 ino = btrfs_ino(inode); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| again: |
| recow = 0; |
| split = start; |
| key.objectid = ino; |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| 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]--; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (key.objectid != ino || |
| key.type != BTRFS_EXTENT_DATA_KEY) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
| if (key.offset > start || extent_end < end) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| 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, |
| ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| new_key.offset = end; |
| btrfs_set_item_key_safe(fs_info, path, &new_key); |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, fi, |
| trans->transid); |
| 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_generation(leaf, fi, |
| trans->transid); |
| 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, |
| 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); |
| btrfs_set_file_extent_generation(leaf, fi, |
| trans->transid); |
| path->slots[0]++; |
| new_key.offset = start; |
| btrfs_set_item_key_safe(fs_info, path, &new_key); |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, fi, |
| trans->transid); |
| 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(path); |
| goto again; |
| } |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| 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_generation(leaf, fi, trans->transid); |
| 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, fs_info, bytenr, num_bytes, |
| 0, root->root_key.objectid, |
| ino, orig_offset); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| if (split == start) { |
| key.offset = start; |
| } else { |
| if (start != key.offset) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| path->slots[0]--; |
| extent_end = end; |
| } |
| recow = 1; |
| } |
| |
| other_start = end; |
| other_end = 0; |
| if (extent_mergeable(leaf, path->slots[0] + 1, |
| ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| if (recow) { |
| btrfs_release_path(path); |
| goto again; |
| } |
| extent_end = other_end; |
| del_slot = path->slots[0] + 1; |
| del_nr++; |
| ret = btrfs_free_extent(trans, fs_info, bytenr, num_bytes, |
| 0, root->root_key.objectid, |
| ino, orig_offset); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| } |
| other_start = 0; |
| other_end = start; |
| if (extent_mergeable(leaf, path->slots[0] - 1, |
| ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| if (recow) { |
| btrfs_release_path(path); |
| goto again; |
| } |
| key.offset = other_start; |
| del_slot = path->slots[0]; |
| del_nr++; |
| ret = btrfs_free_extent(trans, fs_info, bytenr, num_bytes, |
| 0, root->root_key.objectid, |
| ino, orig_offset); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| } |
| 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_set_file_extent_generation(leaf, fi, trans->transid); |
| 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_generation(leaf, fi, trans->transid); |
| 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); |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| } |
| out: |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| /* |
| * 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 inode *inode, |
| struct page *page, u64 pos, |
| bool force_uptodate) |
| { |
| int ret = 0; |
| |
| if (((pos & (PAGE_SIZE - 1)) || force_uptodate) && |
| !PageUptodate(page)) { |
| ret = btrfs_readpage(NULL, page); |
| if (ret) |
| return ret; |
| lock_page(page); |
| if (!PageUptodate(page)) { |
| unlock_page(page); |
| return -EIO; |
| } |
| if (page->mapping != inode->i_mapping) { |
| unlock_page(page); |
| return -EAGAIN; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * this just gets pages into the page cache and locks them down. |
| */ |
| static noinline int prepare_pages(struct inode *inode, struct page **pages, |
| size_t num_pages, loff_t pos, |
| size_t write_bytes, bool force_uptodate) |
| { |
| int i; |
| unsigned long index = pos >> PAGE_SHIFT; |
| gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); |
| int err = 0; |
| int faili; |
| |
| for (i = 0; i < num_pages; i++) { |
| again: |
| pages[i] = find_or_create_page(inode->i_mapping, index + i, |
| mask | __GFP_WRITE); |
| if (!pages[i]) { |
| faili = i - 1; |
| err = -ENOMEM; |
| goto fail; |
| } |
| |
| if (i == 0) |
| err = prepare_uptodate_page(inode, pages[i], pos, |
| force_uptodate); |
| if (!err && i == num_pages - 1) |
| err = prepare_uptodate_page(inode, pages[i], |
| pos + write_bytes, false); |
| if (err) { |
| put_page(pages[i]); |
| if (err == -EAGAIN) { |
| err = 0; |
| goto again; |
| } |
| faili = i - 1; |
| goto fail; |
| } |
| wait_on_page_writeback(pages[i]); |
| } |
| |
| return 0; |
| fail: |
| while (faili >= 0) { |
| unlock_page(pages[faili]); |
| put_page(pages[faili]); |
| faili--; |
| } |
| return err; |
| |
| } |
| |
| static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode, |
| const u64 start, |
| const u64 len, |
| struct extent_state **cached_state) |
| { |
| u64 search_start = start; |
| const u64 end = start + len - 1; |
| |
| while (search_start < end) { |
| const u64 search_len = end - search_start + 1; |
| struct extent_map *em; |
| u64 em_len; |
| int ret = 0; |
| |
| em = btrfs_get_extent(inode, NULL, 0, search_start, |
| search_len, 0); |
| if (IS_ERR(em)) |
| return PTR_ERR(em); |
| |
| if (em->block_start != EXTENT_MAP_HOLE) |
| goto next; |
| |
| em_len = em->len; |
| if (em->start < search_start) |
| em_len -= search_start - em->start; |
| if (em_len > search_len) |
| em_len = search_len; |
| |
| ret = set_extent_bit(&inode->io_tree, search_start, |
| search_start + em_len - 1, |
| EXTENT_DELALLOC_NEW, |
| NULL, cached_state, GFP_NOFS); |
| next: |
| search_start = extent_map_end(em); |
| free_extent_map(em); |
| if (ret) |
| return ret; |
| } |
| return 0; |
| } |
| |
| /* |
| * This function locks the extent and properly waits for data=ordered extents |
| * to finish before allowing the pages to be modified if need. |
| * |
| * The return value: |
| * 1 - the extent is locked |
| * 0 - the extent is not locked, and everything is OK |
| * -EAGAIN - need re-prepare the pages |
| * the other < 0 number - Something wrong happens |
| */ |
| static noinline int |
| lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages, |
| size_t num_pages, loff_t pos, |
| size_t write_bytes, |
| u64 *lockstart, u64 *lockend, |
| struct extent_state **cached_state) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); |
| u64 start_pos; |
| u64 last_pos; |
| int i; |
| int ret = 0; |
| |
| start_pos = round_down(pos, fs_info->sectorsize); |
| last_pos = start_pos |
| + round_up(pos + write_bytes - start_pos, |
| fs_info->sectorsize) - 1; |
| |
| if (start_pos < inode->vfs_inode.i_size || |
| (inode->flags & BTRFS_INODE_PREALLOC)) { |
| struct btrfs_ordered_extent *ordered; |
| unsigned int clear_bits; |
| |
| lock_extent_bits(&inode->io_tree, start_pos, last_pos, |
| cached_state); |
| ordered = btrfs_lookup_ordered_range(inode, start_pos, |
| last_pos - start_pos + 1); |
| if (ordered && |
| ordered->file_offset + ordered->len > start_pos && |
| ordered->file_offset <= last_pos) { |
| unlock_extent_cached(&inode->io_tree, start_pos, |
| last_pos, cached_state, GFP_NOFS); |
| for (i = 0; i < num_pages; i++) { |
| unlock_page(pages[i]); |
| put_page(pages[i]); |
| } |
| btrfs_start_ordered_extent(&inode->vfs_inode, |
| ordered, 1); |
| btrfs_put_ordered_extent(ordered); |
| return -EAGAIN; |
| } |
| if (ordered) |
| btrfs_put_ordered_extent(ordered); |
| ret = btrfs_find_new_delalloc_bytes(inode, start_pos, |
| last_pos - start_pos + 1, |
| cached_state); |
| clear_bits = EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG; |
| if (ret) |
| clear_bits |= EXTENT_DELALLOC_NEW | EXTENT_LOCKED; |
| clear_extent_bit(&inode->io_tree, start_pos, |
| last_pos, clear_bits, |
| (clear_bits & EXTENT_LOCKED) ? 1 : 0, |
| 0, cached_state, GFP_NOFS); |
| if (ret) |
| return ret; |
| *lockstart = start_pos; |
| *lockend = last_pos; |
| ret = 1; |
| } |
| |
| for (i = 0; i < num_pages; i++) { |
| if (clear_page_dirty_for_io(pages[i])) |
| account_page_redirty(pages[i]); |
| set_page_extent_mapped(pages[i]); |
| WARN_ON(!PageLocked(pages[i])); |
| } |
| |
| return ret; |
| } |
| |
| static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos, |
| size_t *write_bytes) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); |
| struct btrfs_root *root = inode->root; |
| struct btrfs_ordered_extent *ordered; |
| u64 lockstart, lockend; |
| u64 num_bytes; |
| int ret; |
| |
| ret = btrfs_start_write_no_snapshoting(root); |
| if (!ret) |
| return -ENOSPC; |
| |
| lockstart = round_down(pos, fs_info->sectorsize); |
| lockend = round_up(pos + *write_bytes, |
| fs_info->sectorsize) - 1; |
| |
| while (1) { |
| lock_extent(&inode->io_tree, lockstart, lockend); |
| ordered = btrfs_lookup_ordered_range(inode, lockstart, |
| lockend - lockstart + 1); |
| if (!ordered) { |
| break; |
| } |
| unlock_extent(&inode->io_tree, lockstart, lockend); |
| btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1); |
| btrfs_put_ordered_extent(ordered); |
| } |
| |
| num_bytes = lockend - lockstart + 1; |
| ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes, |
| NULL, NULL, NULL); |
| if (ret <= 0) { |
| ret = 0; |
| btrfs_end_write_no_snapshoting(root); |
| } else { |
| *write_bytes = min_t(size_t, *write_bytes , |
| num_bytes - pos + lockstart); |
| } |
| |
| unlock_extent(&inode->io_tree, lockstart, lockend); |
| |
| return ret; |
| } |
| |
| static noinline ssize_t __btrfs_buffered_write(struct file *file, |
| struct iov_iter *i, |
| loff_t pos) |
| { |
| struct inode *inode = file_inode(file); |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct page **pages = NULL; |
| struct extent_state *cached_state = NULL; |
| struct extent_changeset *data_reserved = NULL; |
| u64 release_bytes = 0; |
| u64 lockstart; |
| u64 lockend; |
| size_t num_written = 0; |
| int nrptrs; |
| int ret = 0; |
| bool only_release_metadata = false; |
| bool force_page_uptodate = false; |
| bool need_unlock; |
| |
| nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE), |
| PAGE_SIZE / (sizeof(struct page *))); |
| nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied); |
| nrptrs = max(nrptrs, 8); |
| pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL); |
| if (!pages) |
| return -ENOMEM; |
| |
| while (iov_iter_count(i) > 0) { |
| size_t offset = pos & (PAGE_SIZE - 1); |
| size_t sector_offset; |
| size_t write_bytes = min(iov_iter_count(i), |
| nrptrs * (size_t)PAGE_SIZE - |
| offset); |
| size_t num_pages = DIV_ROUND_UP(write_bytes + offset, |
| PAGE_SIZE); |
| size_t reserve_bytes; |
| size_t dirty_pages; |
| size_t copied; |
| size_t dirty_sectors; |
| size_t num_sectors; |
| |
| WARN_ON(num_pages > nrptrs); |
| |
| /* |
| * Fault pages before locking them in prepare_pages |
| * to avoid recursive lock |
| */ |
| if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) { |
| ret = -EFAULT; |
| break; |
| } |
| |
| sector_offset = pos & (fs_info->sectorsize - 1); |
| reserve_bytes = round_up(write_bytes + sector_offset, |
| fs_info->sectorsize); |
| |
| extent_changeset_release(data_reserved); |
| ret = btrfs_check_data_free_space(inode, &data_reserved, pos, |
| write_bytes); |
| if (ret < 0) { |
| if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | |
| BTRFS_INODE_PREALLOC)) && |
| check_can_nocow(BTRFS_I(inode), pos, |
| &write_bytes) > 0) { |
| /* |
| * For nodata cow case, no need to reserve |
| * data space. |
| */ |
| only_release_metadata = true; |
| /* |
| * our prealloc extent may be smaller than |
| * write_bytes, so scale down. |
| */ |
| num_pages = DIV_ROUND_UP(write_bytes + offset, |
| PAGE_SIZE); |
| reserve_bytes = round_up(write_bytes + |
| sector_offset, |
| fs_info->sectorsize); |
| } else { |
| break; |
| } |
| } |
| |
| ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), |
| reserve_bytes); |
| if (ret) { |
| if (!only_release_metadata) |
| btrfs_free_reserved_data_space(inode, |
| data_reserved, pos, |
| write_bytes); |
| else |
| btrfs_end_write_no_snapshoting(root); |
| break; |
| } |
| |
| release_bytes = reserve_bytes; |
| need_unlock = false; |
| again: |
| /* |
| * 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(inode, pages, num_pages, |
| pos, write_bytes, |
| force_page_uptodate); |
| if (ret) |
| break; |
| |
| ret = lock_and_cleanup_extent_if_need(BTRFS_I(inode), pages, |
| num_pages, pos, write_bytes, &lockstart, |
| &lockend, &cached_state); |
| if (ret < 0) { |
| if (ret == -EAGAIN) |
| goto again; |
| break; |
| } else if (ret > 0) { |
| need_unlock = true; |
| ret = 0; |
| } |
| |
| copied = btrfs_copy_from_user(pos, write_bytes, pages, i); |
| |
| num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes); |
| dirty_sectors = round_up(copied + sector_offset, |
| fs_info->sectorsize); |
| dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors); |
| |
| /* |
| * 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) { |
| force_page_uptodate = true; |
| dirty_sectors = 0; |
| dirty_pages = 0; |
| } else { |
| force_page_uptodate = false; |
| dirty_pages = DIV_ROUND_UP(copied + offset, |
| PAGE_SIZE); |
| } |
| |
| /* |
| * 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 and |
| * btrfs_delalloc_release_metadata will decrement it, but |
| * we still have an outstanding extent for the chunk we actually |
| * managed to copy. |
| */ |
| if (num_sectors > dirty_sectors) { |
| /* release everything except the sectors we dirtied */ |
| release_bytes -= dirty_sectors << |
| fs_info->sb->s_blocksize_bits; |
| if (copied > 0) { |
| spin_lock(&BTRFS_I(inode)->lock); |
| BTRFS_I(inode)->outstanding_extents++; |
| spin_unlock(&BTRFS_I(inode)->lock); |
| } |
| if (only_release_metadata) { |
| btrfs_delalloc_release_metadata(BTRFS_I(inode), |
| release_bytes); |
| } else { |
| u64 __pos; |
| |
| __pos = round_down(pos, |
| fs_info->sectorsize) + |
| (dirty_pages << PAGE_SHIFT); |
| btrfs_delalloc_release_space(inode, |
| data_reserved, __pos, |
| release_bytes); |
| } |
| } |
| |
| release_bytes = round_up(copied + sector_offset, |
| fs_info->sectorsize); |
| |
| if (copied > 0) |
| ret = btrfs_dirty_pages(inode, pages, dirty_pages, |
| pos, copied, NULL); |
| if (need_unlock) |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
| lockstart, lockend, &cached_state, |
| GFP_NOFS); |
| if (ret) { |
| btrfs_drop_pages(pages, num_pages); |
| break; |
| } |
| |
| release_bytes = 0; |
| if (only_release_metadata) |
| btrfs_end_write_no_snapshoting(root); |
| |
| if (only_release_metadata && copied > 0) { |
| lockstart = round_down(pos, |
| fs_info->sectorsize); |
| lockend = round_up(pos + copied, |
| fs_info->sectorsize) - 1; |
| |
| set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, |
| lockend, EXTENT_NORESERVE, NULL, |
| NULL, GFP_NOFS); |
| only_release_metadata = false; |
| } |
| |
| btrfs_drop_pages(pages, num_pages); |
| |
| cond_resched(); |
| |
| balance_dirty_pages_ratelimited(inode->i_mapping); |
| if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1) |
| btrfs_btree_balance_dirty(fs_info); |
| |
| pos += copied; |
| num_written += copied; |
| } |
| |
| kfree(pages); |
| |
| if (release_bytes) { |
| if (only_release_metadata) { |
| btrfs_end_write_no_snapshoting(root); |
| btrfs_delalloc_release_metadata(BTRFS_I(inode), |
| release_bytes); |
| } else { |
| btrfs_delalloc_release_space(inode, data_reserved, |
| round_down(pos, fs_info->sectorsize), |
| release_bytes); |
| } |
| } |
| |
| extent_changeset_free(data_reserved); |
| return num_written ? num_written : ret; |
| } |
| |
| static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file_inode(file); |
| loff_t pos = iocb->ki_pos; |
| ssize_t written; |
| ssize_t written_buffered; |
| loff_t endbyte; |
| int err; |
| |
| written = generic_file_direct_write(iocb, from); |
| |
| if (written < 0 || !iov_iter_count(from)) |
| return written; |
| |
| pos += written; |
| written_buffered = __btrfs_buffered_write(file, from, pos); |
| if (written_buffered < 0) { |
| err = written_buffered; |
| goto out; |
| } |
| /* |
| * Ensure all data is persisted. We want the next direct IO read to be |
| * able to read what was just written. |
| */ |
| endbyte = pos + written_buffered - 1; |
| err = btrfs_fdatawrite_range(inode, pos, endbyte); |
| if (err) |
| goto out; |
| err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte); |
| if (err) |
| goto out; |
| written += written_buffered; |
| iocb->ki_pos = pos + written_buffered; |
| invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT, |
| endbyte >> PAGE_SHIFT); |
| out: |
| return written ? written : err; |
| } |
| |
| static void update_time_for_write(struct inode *inode) |
| { |
| struct timespec now; |
| |
| if (IS_NOCMTIME(inode)) |
| return; |
| |
| now = current_time(inode); |
| if (!timespec_equal(&inode->i_mtime, &now)) |
| inode->i_mtime = now; |
| |
| if (!timespec_equal(&inode->i_ctime, &now)) |
| inode->i_ctime = now; |
| |
| if (IS_I_VERSION(inode)) |
| inode_inc_iversion(inode); |
| } |
| |
| static ssize_t btrfs_file_write_iter(struct kiocb *iocb, |
| struct iov_iter *from) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file_inode(file); |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| u64 start_pos; |
| u64 end_pos; |
| ssize_t num_written = 0; |
| bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host); |
| ssize_t err; |
| loff_t pos; |
| size_t count = iov_iter_count(from); |
| loff_t oldsize; |
| int clean_page = 0; |
| |
| if (!inode_trylock(inode)) { |
| if (iocb->ki_flags & IOCB_NOWAIT) |
| return -EAGAIN; |
| inode_lock(inode); |
| } |
| |
| err = generic_write_checks(iocb, from); |
| if (err <= 0) { |
| inode_unlock(inode); |
| return err; |
| } |
| |
| pos = iocb->ki_pos; |
| if (iocb->ki_flags & IOCB_NOWAIT) { |
| /* |
| * We will allocate space in case nodatacow is not set, |
| * so bail |
| */ |
| if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | |
| BTRFS_INODE_PREALLOC)) || |
| check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) { |
| inode_unlock(inode); |
| return -EAGAIN; |
| } |
| } |
| |
| current->backing_dev_info = inode_to_bdi(inode); |
| err = file_remove_privs(file); |
| if (err) { |
| inode_unlock(inode); |
| 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 (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { |
| inode_unlock(inode); |
| err = -EROFS; |
| goto out; |
| } |
| |
| /* |
| * We reserve space for updating the inode when we reserve space for the |
| * extent we are going to write, so we will enospc out there. We don't |
| * need to start yet another transaction to update the inode as we will |
| * update the inode when we finish writing whatever data we write. |
| */ |
| update_time_for_write(inode); |
| |
| start_pos = round_down(pos, fs_info->sectorsize); |
| oldsize = i_size_read(inode); |
| if (start_pos > oldsize) { |
| /* Expand hole size to cover write data, preventing empty gap */ |
| end_pos = round_up(pos + count, |
| fs_info->sectorsize); |
| err = btrfs_cont_expand(inode, oldsize, end_pos); |
| if (err) { |
| inode_unlock(inode); |
| goto out; |
| } |
| if (start_pos > round_up(oldsize, fs_info->sectorsize)) |
| clean_page = 1; |
| } |
| |
| if (sync) |
| atomic_inc(&BTRFS_I(inode)->sync_writers); |
| |
| if (iocb->ki_flags & IOCB_DIRECT) { |
| num_written = __btrfs_direct_write(iocb, from); |
| } else { |
| num_written = __btrfs_buffered_write(file, from, pos); |
| if (num_written > 0) |
| iocb->ki_pos = pos + num_written; |
| if (clean_page) |
| pagecache_isize_extended(inode, oldsize, |
| i_size_read(inode)); |
| } |
| |
| inode_unlock(inode); |
| |
| /* |
| * We also have to set last_sub_trans to the current log transid, |
| * otherwise subsequent syncs to a file that's been synced in this |
| * transaction will appear to have already occurred. |
| */ |
| spin_lock(&BTRFS_I(inode)->lock); |
| BTRFS_I(inode)->last_sub_trans = root->log_transid; |
| spin_unlock(&BTRFS_I(inode)->lock); |
| if (num_written > 0) |
| num_written = generic_write_sync(iocb, num_written); |
| |
| if (sync) |
| atomic_dec(&BTRFS_I(inode)->sync_writers); |
| out: |
| current->backing_dev_info = NULL; |
| return num_written ? num_written : err; |
| } |
| |
| int btrfs_release_file(struct inode *inode, struct file *filp) |
| { |
| if (filp->private_data) |
| btrfs_ioctl_trans_end(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 (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, |
| &BTRFS_I(inode)->runtime_flags)) |
| filemap_flush(inode->i_mapping); |
| return 0; |
| } |
| |
| static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end) |
| { |
| int ret; |
| |
| atomic_inc(&BTRFS_I(inode)->sync_writers); |
| ret = btrfs_fdatawrite_range(inode, start, end); |
| atomic_dec(&BTRFS_I(inode)->sync_writers); |
| |
| return ret; |
| } |
| |
| /* |
| * 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, loff_t start, loff_t end, int datasync) |
| { |
| struct dentry *dentry = file_dentry(file); |
| struct inode *inode = d_inode(dentry); |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct btrfs_trans_handle *trans; |
| struct btrfs_log_ctx ctx; |
| int ret = 0, err; |
| bool full_sync = 0; |
| u64 len; |
| |
| /* |
| * The range length can be represented by u64, we have to do the typecasts |
| * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync() |
| */ |
| len = (u64)end - (u64)start + 1; |
| trace_btrfs_sync_file(file, datasync); |
| |
| /* |
| * We write the dirty pages in the range and wait until they complete |
| * out of the ->i_mutex. If so, we can flush the dirty pages by |
| * multi-task, and make the performance up. See |
| * btrfs_wait_ordered_range for an explanation of the ASYNC check. |
| */ |
| ret = start_ordered_ops(inode, start, end); |
| if (ret) |
| goto out; |
| |
| inode_lock(inode); |
| atomic_inc(&root->log_batch); |
| full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| &BTRFS_I(inode)->runtime_flags); |
| /* |
| * We might have have had more pages made dirty after calling |
| * start_ordered_ops and before acquiring the inode's i_mutex. |
| */ |
| if (full_sync) { |
| /* |
| * For a full sync, we need to make sure any ordered operations |
| * start and finish before we start logging the inode, so that |
| * all extents are persisted and the respective file extent |
| * items are in the fs/subvol btree. |
| */ |
| ret = btrfs_wait_ordered_range(inode, start, len); |
| } else { |
| /* |
| * Start any new ordered operations before starting to log the |
| * inode. We will wait for them to finish in btrfs_sync_log(). |
| * |
| * Right before acquiring the inode's mutex, we might have new |
| * writes dirtying pages, which won't immediately start the |
| * respective ordered operations - that is done through the |
| * fill_delalloc callbacks invoked from the writepage and |
| * writepages address space operations. So make sure we start |
| * all ordered operations before starting to log our inode. Not |
| * doing this means that while logging the inode, writeback |
| * could start and invoke writepage/writepages, which would call |
| * the fill_delalloc callbacks (cow_file_range, |
| * submit_compressed_extents). These callbacks add first an |
| * extent map to the modified list of extents and then create |
| * the respective ordered operation, which means in |
| * tree-log.c:btrfs_log_inode() we might capture all existing |
| * ordered operations (with btrfs_get_logged_extents()) before |
| * the fill_delalloc callback adds its ordered operation, and by |
| * the time we visit the modified list of extent maps (with |
| * btrfs_log_changed_extents()), we see and process the extent |
| * map they created. We then use the extent map to construct a |
| * file extent item for logging without waiting for the |
| * respective ordered operation to finish - this file extent |
| * item points to a disk location that might not have yet been |
| * written to, containing random data - so after a crash a log |
| * replay will make our inode have file extent items that point |
| * to disk locations containing invalid data, as we returned |
| * success to userspace without waiting for the respective |
| * ordered operation to finish, because it wasn't captured by |
| * btrfs_get_logged_extents(). |
| */ |
| ret = start_ordered_ops(inode, start, end); |
| } |
| if (ret) { |
| inode_unlock(inode); |
| goto out; |
| } |
| atomic_inc(&root->log_batch); |
| |
| /* |
| * If the last transaction that changed this file was before the current |
| * transaction and we have the full sync flag set in our inode, we can |
| * bail out now without any syncing. |
| * |
| * Note that we can't bail out if the full sync flag isn't set. This is |
| * because when the full sync flag is set we start all ordered extents |
| * and wait for them to fully complete - when they complete they update |
| * the inode's last_trans field through: |
| * |
| * btrfs_finish_ordered_io() -> |
| * btrfs_update_inode_fallback() -> |
| * btrfs_update_inode() -> |
| * btrfs_set_inode_last_trans() |
| * |
| * So we are sure that last_trans is up to date and can do this check to |
| * bail out safely. For the fast path, when the full sync flag is not |
| * set in our inode, we can not do it because we start only our ordered |
| * extents and don't wait for them to complete (that is when |
| * btrfs_finish_ordered_io runs), so here at this point their last_trans |
| * value might be less than or equals to fs_info->last_trans_committed, |
| * and setting a speculative last_trans for an inode when a buffered |
| * write is made (such as fs_info->generation + 1 for example) would not |
| * be reliable since after setting the value and before fsync is called |
| * any number of transactions can start and commit (transaction kthread |
| * commits the current transaction periodically), and a transaction |
| * commit does not start nor waits for ordered extents to complete. |
| */ |
| smp_mb(); |
| if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) || |
| (full_sync && BTRFS_I(inode)->last_trans <= |
| fs_info->last_trans_committed) || |
| (!btrfs_have_ordered_extents_in_range(inode, start, len) && |
| BTRFS_I(inode)->last_trans |
| <= fs_info->last_trans_committed)) { |
| /* |
| * We've had everything committed since the last time we were |
| * modified so clear this flag in case it was set for whatever |
| * reason, it's no longer relevant. |
| */ |
| clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| &BTRFS_I(inode)->runtime_flags); |
| /* |
| * An ordered extent might have started before and completed |
| * already with io errors, in which case the inode was not |
| * updated and we end up here. So check the inode's mapping |
| * for any errors that might have happened since we last |
| * checked called fsync. |
| */ |
| ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err); |
| inode_unlock(inode); |
| goto out; |
| } |
| |
| /* |
| * ok we haven't committed the transaction yet, lets do a commit |
| */ |
| if (file->private_data) |
| btrfs_ioctl_trans_end(file); |
| |
| /* |
| * We use start here because we will need to wait on the IO to complete |
| * in btrfs_sync_log, which could require joining a transaction (for |
| * example checking cross references in the nocow path). If we use join |
| * here we could get into a situation where we're waiting on IO to |
| * happen that is blocked on a transaction trying to commit. With start |
| * we inc the extwriter counter, so we wait for all extwriters to exit |
| * before we start blocking join'ers. This comment is to keep somebody |
| * from thinking they are super smart and changing this to |
| * btrfs_join_transaction *cough*Josef*cough*. |
| */ |
| trans = btrfs_start_transaction(root, 0); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| inode_unlock(inode); |
| goto out; |
| } |
| trans->sync = true; |
| |
| btrfs_init_log_ctx(&ctx, inode); |
| |
| ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx); |
| if (ret < 0) { |
| /* Fallthrough and commit/free transaction. */ |
| ret = 1; |
| } |
| |
| /* 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. |
| */ |
| inode_unlock(inode); |
| |
| /* |
| * If any of the ordered extents had an error, just return it to user |
| * space, so that the application knows some writes didn't succeed and |
| * can take proper action (retry for e.g.). Blindly committing the |
| * transaction in this case, would fool userspace that everything was |
| * successful. And we also want to make sure our log doesn't contain |
| * file extent items pointing to extents that weren't fully written to - |
| * just like in the non fast fsync path, where we check for the ordered |
| * operation's error flag before writing to the log tree and return -EIO |
| * if any of them had this flag set (btrfs_wait_ordered_range) - |
| * therefore we need to check for errors in the ordered operations, |
| * which are indicated by ctx.io_err. |
| */ |
| if (ctx.io_err) { |
| btrfs_end_transaction(trans); |
| ret = ctx.io_err; |
| goto out; |
| } |
| |
| if (ret != BTRFS_NO_LOG_SYNC) { |
| if (!ret) { |
| ret = btrfs_sync_log(trans, root, &ctx); |
| if (!ret) { |
| ret = btrfs_end_transaction(trans); |
| goto out; |
| } |
| } |
| if (!full_sync) { |
| ret = btrfs_wait_ordered_range(inode, start, len); |
| if (ret) { |
| btrfs_end_transaction(trans); |
| goto out; |
| } |
| } |
| ret = btrfs_commit_transaction(trans); |
| } else { |
| ret = btrfs_end_transaction(trans); |
| } |
| out: |
| err = file_check_and_advance_wb_err(file); |
| if (!ret) |
| ret = err; |
| return ret > 0 ? -EIO : ret; |
| } |
| |
| static const struct vm_operations_struct btrfs_file_vm_ops = { |
| .fault = filemap_fault, |
| .map_pages = filemap_map_pages, |
| .page_mkwrite = btrfs_page_mkwrite, |
| }; |
| |
| static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) |
| { |
| struct address_space *mapping = filp->f_mapping; |
| |
| if (!mapping->a_ops->readpage) |
| return -ENOEXEC; |
| |
| file_accessed(filp); |
| vma->vm_ops = &btrfs_file_vm_ops; |
| |
| return 0; |
| } |
| |
| static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf, |
| int slot, u64 start, u64 end) |
| { |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| |
| if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
| return 0; |
| |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| if (key.objectid != btrfs_ino(inode) || |
| 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) |
| return 0; |
| |
| if (btrfs_file_extent_disk_bytenr(leaf, fi)) |
| return 0; |
| |
| if (key.offset == end) |
| return 1; |
| if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start) |
| return 1; |
| return 0; |
| } |
| |
| static int fill_holes(struct btrfs_trans_handle *trans, |
| struct btrfs_inode *inode, |
| struct btrfs_path *path, u64 offset, u64 end) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); |
| struct btrfs_root *root = inode->root; |
| struct extent_buffer *leaf; |
| struct btrfs_file_extent_item *fi; |
| struct extent_map *hole_em; |
| struct extent_map_tree *em_tree = &inode->extent_tree; |
| struct btrfs_key key; |
| int ret; |
| |
| if (btrfs_fs_incompat(fs_info, NO_HOLES)) |
| goto out; |
| |
| key.objectid = btrfs_ino(inode); |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| key.offset = offset; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, 0, 1); |
| if (ret <= 0) { |
| /* |
| * We should have dropped this offset, so if we find it then |
| * something has gone horribly wrong. |
| */ |
| if (ret == 0) |
| ret = -EINVAL; |
| return ret; |
| } |
| |
| leaf = path->nodes[0]; |
| if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) { |
| u64 num_bytes; |
| |
| path->slots[0]--; |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + |
| end - offset; |
| btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_offset(leaf, fi, 0); |
| btrfs_mark_buffer_dirty(leaf); |
| goto out; |
| } |
| |
| if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) { |
| u64 num_bytes; |
| |
| key.offset = offset; |
| btrfs_set_item_key_safe(fs_info, path, &key); |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end - |
| offset; |
| btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_offset(leaf, fi, 0); |
| btrfs_mark_buffer_dirty(leaf); |
| goto out; |
| } |
| btrfs_release_path(path); |
| |
| ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), |
| offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0); |
| if (ret) |
| return ret; |
| |
| out: |
| btrfs_release_path(path); |
| |
| hole_em = alloc_extent_map(); |
| if (!hole_em) { |
| btrfs_drop_extent_cache(inode, offset, end - 1, 0); |
| set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags); |
| } else { |
| hole_em->start = offset; |
| hole_em->len = end - offset; |
| hole_em->ram_bytes = hole_em->len; |
| hole_em->orig_start = offset; |
| |
| hole_em->block_start = EXTENT_MAP_HOLE; |
| hole_em->block_len = 0; |
| hole_em->orig_block_len = 0; |
| hole_em->bdev = fs_info->fs_devices->latest_bdev; |
| hole_em->compress_type = BTRFS_COMPRESS_NONE; |
| hole_em->generation = trans->transid; |
| |
| do { |
| btrfs_drop_extent_cache(inode, offset, end - 1, 0); |
| write_lock(&em_tree->lock); |
| ret = add_extent_mapping(em_tree, hole_em, 1); |
| write_unlock(&em_tree->lock); |
| } while (ret == -EEXIST); |
| free_extent_map(hole_em); |
| if (ret) |
| set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| &inode->runtime_flags); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Find a hole extent on given inode and change start/len to the end of hole |
| * extent.(hole/vacuum extent whose em->start <= start && |
| * em->start + em->len > start) |
| * When a hole extent is found, return 1 and modify start/len. |
| */ |
| static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct extent_map *em; |
| int ret = 0; |
| |
| em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, |
| round_down(*start, fs_info->sectorsize), |
| round_up(*len, fs_info->sectorsize), 0); |
| if (IS_ERR(em)) |
| return PTR_ERR(em); |
| |
| /* Hole or vacuum extent(only exists in no-hole mode) */ |
| if (em->block_start == EXTENT_MAP_HOLE) { |
| ret = 1; |
| *len = em->start + em->len > *start + *len ? |
| 0 : *start + *len - em->start - em->len; |
| *start = em->start + em->len; |
| } |
| free_extent_map(em); |
| return ret; |
| } |
| |
| static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_state *cached_state = NULL; |
| struct btrfs_path *path; |
| struct btrfs_block_rsv *rsv; |
| struct btrfs_trans_handle *trans; |
| u64 lockstart; |
| u64 lockend; |
| u64 tail_start; |
| u64 tail_len; |
| u64 orig_start = offset; |
| u64 cur_offset; |
| u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1); |
| u64 drop_end; |
| int ret = 0; |
| int err = 0; |
| unsigned int rsv_count; |
| bool same_block; |
| bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES); |
| u64 ino_size; |
| bool truncated_block = false; |
| bool updated_inode = false; |
| |
| ret = btrfs_wait_ordered_range(inode, offset, len); |
| if (ret) |
| return ret; |
| |
| inode_lock(inode); |
| ino_size = round_up(inode->i_size, fs_info->sectorsize); |
| ret = find_first_non_hole(inode, &offset, &len); |
| if (ret < 0) |
| goto out_only_mutex; |
| if (ret && !len) { |
| /* Already in a large hole */ |
| ret = 0; |
| goto out_only_mutex; |
| } |
| |
| lockstart = round_up(offset, btrfs_inode_sectorsize(inode)); |
| lockend = round_down(offset + len, |
| btrfs_inode_sectorsize(inode)) - 1; |
| same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset)) |
| == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)); |
| /* |
| * We needn't truncate any block which is beyond the end of the file |
| * because we are sure there is no data there. |
| */ |
| /* |
| * Only do this if we are in the same block and we aren't doing the |
| * entire block. |
| */ |
| if (same_block && len < fs_info->sectorsize) { |
| if (offset < ino_size) { |
| truncated_block = true; |
| ret = btrfs_truncate_block(inode, offset, len, 0); |
| } else { |
| ret = 0; |
| } |
| goto out_only_mutex; |
| } |
| |
| /* zero back part of the first block */ |
| if (offset < ino_size) { |
| truncated_block = true; |
| ret = btrfs_truncate_block(inode, offset, 0, 0); |
| if (ret) { |
| inode_unlock(inode); |
| return ret; |
| } |
| } |
| |
| /* Check the aligned pages after the first unaligned page, |
| * if offset != orig_start, which means the first unaligned page |
| * including several following pages are already in holes, |
| * the extra check can be skipped */ |
| if (offset == orig_start) { |
| /* after truncate page, check hole again */ |
| len = offset + len - lockstart; |
| offset = lockstart; |
| ret = find_first_non_hole(inode, &offset, &len); |
| if (ret < 0) |
| goto out_only_mutex; |
| if (ret && !len) { |
| ret = 0; |
| goto out_only_mutex; |
| } |
| lockstart = offset; |
| } |
| |
| /* Check the tail unaligned part is in a hole */ |
| tail_start = lockend + 1; |
| tail_len = offset + len - tail_start; |
| if (tail_len) { |
| ret = find_first_non_hole(inode, &tail_start, &tail_len); |
| if (unlikely(ret < 0)) |
| goto out_only_mutex; |
| if (!ret) { |
| /* zero the front end of the last page */ |
| if (tail_start + tail_len < ino_size) { |
| truncated_block = true; |
| ret = btrfs_truncate_block(inode, |
| tail_start + tail_len, |
| 0, 1); |
| if (ret) |
| goto out_only_mutex; |
| } |
| } |
| } |
| |
| if (lockend < lockstart) { |
| ret = 0; |
| goto out_only_mutex; |
| } |
| |
| while (1) { |
| struct btrfs_ordered_extent *ordered; |
| |
| truncate_pagecache_range(inode, lockstart, lockend); |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| &cached_state); |
| ordered = btrfs_lookup_first_ordered_extent(inode, lockend); |
| |
| /* |
| * We need to make sure we have no ordered extents in this range |
| * and nobody raced in and read a page in this range, if we did |
| * we need to try again. |
| */ |
| if ((!ordered || |
| (ordered->file_offset + ordered->len <= lockstart || |
| ordered->file_offset > lockend)) && |
| !btrfs_page_exists_in_range(inode, lockstart, lockend)) { |
| if (ordered) |
| btrfs_put_ordered_extent(ordered); |
| break; |
| } |
| if (ordered) |
| btrfs_put_ordered_extent(ordered); |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, |
| lockend, &cached_state, GFP_NOFS); |
| ret = btrfs_wait_ordered_range(inode, lockstart, |
| lockend - lockstart + 1); |
| if (ret) { |
| inode_unlock(inode); |
| return ret; |
| } |
| } |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); |
| if (!rsv) { |
| ret = -ENOMEM; |
| goto out_free; |
| } |
| rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1); |
| rsv->failfast = 1; |
| |
| /* |
| * 1 - update the inode |
| * 1 - removing the extents in the range |
| * 1 - adding the hole extent if no_holes isn't set |
| */ |
| rsv_count = no_holes ? 2 : 3; |
| trans = btrfs_start_transaction(root, rsv_count); |
| if (IS_ERR(trans)) { |
| err = PTR_ERR(trans); |
| goto out_free; |
| } |
| |
| ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, |
| min_size, 0); |
| BUG_ON(ret); |
| trans->block_rsv = rsv; |
| |
| cur_offset = lockstart; |
| len = lockend - cur_offset; |
| while (cur_offset < lockend) { |
| ret = __btrfs_drop_extents(trans, root, inode, path, |
| cur_offset, lockend + 1, |
| &drop_end, 1, 0, 0, NULL); |
| if (ret != -ENOSPC) |
| break; |
| |
| trans->block_rsv = &fs_info->trans_block_rsv; |
| |
| if (cur_offset < drop_end && cur_offset < ino_size) { |
| ret = fill_holes(trans, BTRFS_I(inode), path, |
| cur_offset, drop_end); |
| if (ret) { |
| /* |
| * If we failed then we didn't insert our hole |
| * entries for the area we dropped, so now the |
| * fs is corrupted, so we must abort the |
| * transaction. |
| */ |
| btrfs_abort_transaction(trans, ret); |
| err = ret; |
| break; |
| } |
| } |
| |
| cur_offset = drop_end; |
| |
| ret = btrfs_update_inode(trans, root, inode); |
| if (ret) { |
| err = ret; |
| break; |
| } |
| |
| btrfs_end_transaction(trans); |
| btrfs_btree_balance_dirty(fs_info); |
| |
| trans = btrfs_start_transaction(root, rsv_count); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| trans = NULL; |
| break; |
| } |
| |
| ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, |
| rsv, min_size, 0); |
| BUG_ON(ret); /* shouldn't happen */ |
| trans->block_rsv = rsv; |
| |
| ret = find_first_non_hole(inode, &cur_offset, &len); |
| if (unlikely(ret < 0)) |
| break; |
| if (ret && !len) { |
| ret = 0; |
| break; |
| } |
| } |
| |
| if (ret) { |
| err = ret; |
| goto out_trans; |
| } |
| |
| trans->block_rsv = &fs_info->trans_block_rsv; |
| /* |
| * If we are using the NO_HOLES feature we might have had already an |
| * hole that overlaps a part of the region [lockstart, lockend] and |
| * ends at (or beyond) lockend. Since we have no file extent items to |
| * represent holes, drop_end can be less than lockend and so we must |
| * make sure we have an extent map representing the existing hole (the |
| * call to __btrfs_drop_extents() might have dropped the existing extent |
| * map representing the existing hole), otherwise the fast fsync path |
| * will not record the existence of the hole region |
| * [existing_hole_start, lockend]. |
| */ |
| if (drop_end <= lockend) |
| drop_end = lockend + 1; |
| /* |
| * Don't insert file hole extent item if it's for a range beyond eof |
| * (because it's useless) or if it represents a 0 bytes range (when |
| * cur_offset == drop_end). |
| */ |
| if (cur_offset < ino_size && cur_offset < drop_end) { |
| ret = fill_holes(trans, BTRFS_I(inode), path, |
| cur_offset, drop_end); |
| if (ret) { |
| /* Same comment as above. */ |
| btrfs_abort_transaction(trans, ret); |
| err = ret; |
| goto out_trans; |
| } |
| } |
| |
| out_trans: |
| if (!trans) |
| goto out_free; |
| |
| inode_inc_iversion(inode); |
| inode->i_mtime = inode->i_ctime = current_time(inode); |
| |
| trans->block_rsv = &fs_info->trans_block_rsv; |
| ret = btrfs_update_inode(trans, root, inode); |
| updated_inode = true; |
| btrfs_end_transaction(trans); |
| btrfs_btree_balance_dirty(fs_info); |
| out_free: |
| btrfs_free_path(path); |
| btrfs_free_block_rsv(fs_info, rsv); |
| out: |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| &cached_state, GFP_NOFS); |
| out_only_mutex: |
| if (!updated_inode && truncated_block && !ret && !err) { |
| /* |
| * If we only end up zeroing part of a page, we still need to |
| * update the inode item, so that all the time fields are |
| * updated as well as the necessary btrfs inode in memory fields |
| * for detecting, at fsync time, if the inode isn't yet in the |
| * log tree or it's there but not up to date. |
| */ |
| trans = btrfs_start_transaction(root, 1); |
| if (IS_ERR(trans)) { |
| err = PTR_ERR(trans); |
| } else { |
| err = btrfs_update_inode(trans, root, inode); |
| ret = btrfs_end_transaction(trans); |
| } |
| } |
| inode_unlock(inode); |
| if (ret && !err) |
| err = ret; |
| return err; |
| } |
| |
| /* Helper structure to record which range is already reserved */ |
| struct falloc_range { |
| struct list_head list; |
| u64 start; |
| u64 len; |
| }; |
| |
| /* |
| * Helper function to add falloc range |
| * |
| * Caller should have locked the larger range of extent containing |
| * [start, len) |
| */ |
| static int add_falloc_range(struct list_head *head, u64 start, u64 len) |
| { |
| struct falloc_range *prev = NULL; |
| struct falloc_range *range = NULL; |
| |
| if (list_empty(head)) |
| goto insert; |
| |
| /* |
| * As fallocate iterate by bytenr order, we only need to check |
| * the last range. |
| */ |
| prev = list_entry(head->prev, struct falloc_range, list); |
| if (prev->start + prev->len == start) { |
| prev->len += len; |
| return 0; |
| } |
| insert: |
| range = kmalloc(sizeof(*range), GFP_KERNEL); |
| if (!range) |
| return -ENOMEM; |
| range->start = start; |
| range->len = len; |
| list_add_tail(&range->list, head); |
| return 0; |
| } |
| |
| static long btrfs_fallocate(struct file *file, int mode, |
| loff_t offset, loff_t len) |
| { |
| struct inode *inode = file_inode(file); |
| struct extent_state *cached_state = NULL; |
| struct extent_changeset *data_reserved = NULL; |
| struct falloc_range *range; |
| struct falloc_range *tmp; |
| struct list_head reserve_list; |
| u64 cur_offset; |
| u64 last_byte; |
| u64 alloc_start; |
| u64 alloc_end; |
| u64 alloc_hint = 0; |
| u64 locked_end; |
| u64 actual_end = 0; |
| struct extent_map *em; |
| int blocksize = btrfs_inode_sectorsize(inode); |
| int ret; |
| |
| alloc_start = round_down(offset, blocksize); |
| alloc_end = round_up(offset + len, blocksize); |
| cur_offset = alloc_start; |
| |
| /* Make sure we aren't being give some crap mode */ |
| if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
| return -EOPNOTSUPP; |
| |
| if (mode & FALLOC_FL_PUNCH_HOLE) |
| return btrfs_punch_hole(inode, offset, len); |
| |
| /* |
| * Only trigger disk allocation, don't trigger qgroup reserve |
| * |
| * For qgroup space, it will be checked later. |
| */ |
| ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), |
| alloc_end - alloc_start); |
| if (ret < 0) |
| return ret; |
| |
| inode_lock(inode); |
| |
| if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) { |
| ret = inode_newsize_ok(inode, offset + len); |
| if (ret) |
| goto out; |
| } |
| |
| /* |
| * TODO: Move these two operations after we have checked |
| * accurate reserved space, or fallocate can still fail but |
| * with page truncated or size expanded. |
| * |
| * But that's a minor problem and won't do much harm BTW. |
| */ |
| if (alloc_start > inode->i_size) { |
| ret = btrfs_cont_expand(inode, i_size_read(inode), |
| alloc_start); |
| if (ret) |
| goto out; |
| } else if (offset + len > inode->i_size) { |
| /* |
| * If we are fallocating from the end of the file onward we |
| * need to zero out the end of the block if i_size lands in the |
| * middle of a block. |
| */ |
| ret = btrfs_truncate_block(inode, inode->i_size, 0, 0); |
| if (ret) |
| goto out; |
| } |
| |
| /* |
| * wait for ordered IO before we have any locks. We'll loop again |
| * below with the locks held. |
| */ |
| ret = btrfs_wait_ordered_range(inode, alloc_start, |
| alloc_end - alloc_start); |
| if (ret) |
| goto out; |
| |
| locked_end = alloc_end - 1; |
| while (1) { |
| struct btrfs_ordered_extent *ordered; |
| |
| /* the extent lock is ordered inside the running |
| * transaction |
| */ |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start, |
| locked_end, &cached_state); |
| ordered = btrfs_lookup_first_ordered_extent(inode, |
| alloc_end - 1); |
| if (ordered && |
| ordered->file_offset + ordered->len > alloc_start && |
| ordered->file_offset < alloc_end) { |
| btrfs_put_ordered_extent(ordered); |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
| alloc_start, locked_end, |
| &cached_state, GFP_KERNEL); |
| /* |
| * we can't wait on the range with the transaction |
| * running or with the extent lock held |
| */ |
| ret = btrfs_wait_ordered_range(inode, alloc_start, |
| alloc_end - alloc_start); |
| if (ret) |
| goto out; |
| } else { |
| if (ordered) |
| btrfs_put_ordered_extent(ordered); |
| break; |
| } |
| } |
| |
| /* First, check if we exceed the qgroup limit */ |
| INIT_LIST_HEAD(&reserve_list); |
| while (1) { |
| em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset, |
| alloc_end - cur_offset, 0); |
| if (IS_ERR(em)) { |
| ret = PTR_ERR(em); |
| break; |
| } |
| last_byte = min(extent_map_end(em), alloc_end); |
| actual_end = min_t(u64, extent_map_end(em), offset + len); |
| last_byte = ALIGN(last_byte, blocksize); |
| if (em->block_start == EXTENT_MAP_HOLE || |
| (cur_offset >= inode->i_size && |
| !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { |
| ret = add_falloc_range(&reserve_list, cur_offset, |
| last_byte - cur_offset); |
| if (ret < 0) { |
| free_extent_map(em); |
| break; |
| } |
| ret = btrfs_qgroup_reserve_data(inode, &data_reserved, |
| cur_offset, last_byte - cur_offset); |
| if (ret < 0) { |
| free_extent_map(em); |
| break; |
| } |
| } else { |
| /* |
| * Do not need to reserve unwritten extent for this |
| * range, free reserved data space first, otherwise |
| * it'll result in false ENOSPC error. |
| */ |
| btrfs_free_reserved_data_space(inode, data_reserved, |
| cur_offset, last_byte - cur_offset); |
| } |
| free_extent_map(em); |
| cur_offset = last_byte; |
| if (cur_offset >= alloc_end) |
| break; |
| } |
| |
| /* |
| * If ret is still 0, means we're OK to fallocate. |
| * Or just cleanup the list and exit. |
| */ |
| list_for_each_entry_safe(range, tmp, &reserve_list, list) { |
| if (!ret) |
| ret = btrfs_prealloc_file_range(inode, mode, |
| range->start, |
| range->len, i_blocksize(inode), |
| offset + len, &alloc_hint); |
| else |
| btrfs_free_reserved_data_space(inode, |
| data_reserved, range->start, |
| range->len); |
| list_del(&range->list); |
| kfree(range); |
| } |
| if (ret < 0) |
| goto out_unlock; |
| |
| if (actual_end > inode->i_size && |
| !(mode & FALLOC_FL_KEEP_SIZE)) { |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| |
| /* |
| * We didn't need to allocate any more space, but we |
| * still extended the size of the file so we need to |
| * update i_size and the inode item. |
| */ |
| trans = btrfs_start_transaction(root, 1); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| } else { |
| inode->i_ctime = current_time(inode); |
| i_size_write(inode, actual_end); |
| btrfs_ordered_update_i_size(inode, actual_end, NULL); |
| ret = btrfs_update_inode(trans, root, inode); |
| if (ret) |
| btrfs_end_transaction(trans); |
| else |
| ret = btrfs_end_transaction(trans); |
| } |
| } |
| out_unlock: |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end, |
| &cached_state, GFP_KERNEL); |
| out: |
| inode_unlock(inode); |
| /* Let go of our reservation. */ |
| if (ret != 0) |
| btrfs_free_reserved_data_space(inode, data_reserved, |
| alloc_start, alloc_end - cur_offset); |
| extent_changeset_free(data_reserved); |
| return ret; |
| } |
| |
| static int find_desired_extent(struct inode *inode, loff_t *offset, int whence) |
| { |
| struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
| struct extent_map *em = NULL; |
| struct extent_state *cached_state = NULL; |
| u64 lockstart; |
| u64 lockend; |
| u64 start; |
| u64 len; |
| int ret = 0; |
| |
| if (inode->i_size == 0) |
| return -ENXIO; |
| |
| /* |
| * *offset can be negative, in this case we start finding DATA/HOLE from |
| * the very start of the file. |
| */ |
| start = max_t(loff_t, 0, *offset); |
| |
| lockstart = round_down(start, fs_info->sectorsize); |
| lockend = round_up(i_size_read(inode), |
| fs_info->sectorsize); |
| if (lockend <= lockstart) |
| lockend = lockstart + fs_info->sectorsize; |
| lockend--; |
| len = lockend - lockstart + 1; |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| &cached_state); |
| |
| while (start < inode->i_size) { |
| em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0, |
| start, len, 0); |
| if (IS_ERR(em)) { |
| ret = PTR_ERR(em); |
| em = NULL; |
| break; |
| } |
| |
| if (whence == SEEK_HOLE && |
| (em->block_start == EXTENT_MAP_HOLE || |
| test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) |
| break; |
| else if (whence == SEEK_DATA && |
| (em->block_start != EXTENT_MAP_HOLE && |
| !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) |
| break; |
| |
| start = em->start + em->len; |
| free_extent_map(em); |
| em = NULL; |
| cond_resched(); |
| } |
| free_extent_map(em); |
| if (!ret) { |
| if (whence == SEEK_DATA && start >= inode->i_size) |
| ret = -ENXIO; |
| else |
| *offset = min_t(loff_t, start, inode->i_size); |
| } |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| &cached_state, GFP_NOFS); |
| return ret; |
| } |
| |
| static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) |
| { |
| struct inode *inode = file->f_mapping->host; |
| int ret; |
| |
|
|