| /* |
| * 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/statfs.h> |
| #include <linux/compat.h> |
| #include <linux/slab.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" |
| #include "volumes.h" |
| |
| /* |
| * 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 void __btrfs_add_inode_defrag(struct inode *inode, |
| struct inode_defrag *defrag) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct inode_defrag *entry; |
| struct rb_node **p; |
| struct rb_node *parent = NULL; |
| int ret; |
| |
| p = &root->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; |
| goto exists; |
| } |
| } |
| set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); |
| rb_link_node(&defrag->rb_node, parent, p); |
| rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes); |
| return; |
| |
| exists: |
| kfree(defrag); |
| return; |
| |
| } |
| |
| /* |
| * insert a defrag record for this inode if auto defrag is |
| * enabled |
| */ |
| int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, |
| struct inode *inode) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct inode_defrag *defrag; |
| u64 transid; |
| |
| if (!btrfs_test_opt(root, AUTO_DEFRAG)) |
| return 0; |
| |
| if (btrfs_fs_closing(root->fs_info)) |
| return 0; |
| |
| if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) |
| return 0; |
| |
| if (trans) |
| transid = trans->transid; |
| else |
| transid = BTRFS_I(inode)->root->last_trans; |
| |
| defrag = kzalloc(sizeof(*defrag), GFP_NOFS); |
| if (!defrag) |
| return -ENOMEM; |
| |
| defrag->ino = btrfs_ino(inode); |
| defrag->transid = transid; |
| defrag->root = root->root_key.objectid; |
| |
| spin_lock(&root->fs_info->defrag_inodes_lock); |
| if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) |
| __btrfs_add_inode_defrag(inode, defrag); |
| else |
| kfree(defrag); |
| spin_unlock(&root->fs_info->defrag_inodes_lock); |
| return 0; |
| } |
| |
| /* |
| * must be called with the defrag_inodes lock held |
| */ |
| struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info, |
| u64 root, u64 ino, |
| struct rb_node **next) |
| { |
| 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; |
| |
| p = 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 |
| return entry; |
| } |
| |
| if (next) { |
| while (parent && __compare_inode_defrag(&tmp, entry) > 0) { |
| parent = rb_next(parent); |
| entry = rb_entry(parent, struct inode_defrag, rb_node); |
| } |
| *next = parent; |
| } |
| return NULL; |
| } |
| |
| /* |
| * 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; |
| struct btrfs_root *inode_root; |
| struct inode *inode; |
| struct rb_node *n; |
| struct btrfs_key key; |
| struct btrfs_ioctl_defrag_range_args range; |
| u64 first_ino = 0; |
| u64 root_objectid = 0; |
| int num_defrag; |
| int defrag_batch = 1024; |
| |
| memset(&range, 0, sizeof(range)); |
| range.len = (u64)-1; |
| |
| atomic_inc(&fs_info->defrag_running); |
| spin_lock(&fs_info->defrag_inodes_lock); |
| while(1) { |
| n = NULL; |
| |
| /* find an inode to defrag */ |
| defrag = btrfs_find_defrag_inode(fs_info, root_objectid, |
| first_ino, &n); |
| if (!defrag) { |
| if (n) { |
| defrag = rb_entry(n, struct inode_defrag, |
| rb_node); |
| } else if (root_objectid || first_ino) { |
| root_objectid = 0; |
| first_ino = 0; |
| continue; |
| } else { |
| break; |
| } |
| } |
| |
| /* remove it from the rbtree */ |
| first_ino = defrag->ino + 1; |
| root_objectid = defrag->root; |
| rb_erase(&defrag->rb_node, &fs_info->defrag_inodes); |
| |
| if (btrfs_fs_closing(fs_info)) |
| goto next_free; |
| |
| spin_unlock(&fs_info->defrag_inodes_lock); |
| |
| /* get the inode */ |
| key.objectid = defrag->root; |
| btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); |
| key.offset = (u64)-1; |
| inode_root = btrfs_read_fs_root_no_name(fs_info, &key); |
| if (IS_ERR(inode_root)) |
| goto next; |
| |
| key.objectid = defrag->ino; |
| btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); |
| key.offset = 0; |
| |
| inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL); |
| if (IS_ERR(inode)) |
| goto next; |
| |
| /* do a chunk of defrag */ |
| clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); |
| range.start = defrag->last_offset; |
| num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid, |
| defrag_batch); |
| /* |
| * if we filled the whole defrag batch, there |
| * must be more work to do. Queue this defrag |
| * again |
| */ |
| if (num_defrag == defrag_batch) { |
| defrag->last_offset = range.start; |
| __btrfs_add_inode_defrag(inode, defrag); |
| /* |
| * we don't want to kfree defrag, we added it back to |
| * the rbtree |
| */ |
| defrag = NULL; |
| } 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_add_inode_defrag(inode, defrag); |
| defrag = NULL; |
| } |
| |
| iput(inode); |
| next: |
| spin_lock(&fs_info->defrag_inodes_lock); |
| next_free: |
| kfree(defrag); |
| } |
| spin_unlock(&fs_info->defrag_inodes_lock); |
| |
| 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, int num_pages, |
| size_t write_bytes, |
| struct page **prepared_pages, |
| struct iov_iter *i) |
| { |
| size_t copied = 0; |
| size_t total_copied = 0; |
| int pg = 0; |
| int offset = pos & (PAGE_CACHE_SIZE - 1); |
| |
| while (write_bytes > 0) { |
| size_t count = min_t(size_t, |
| PAGE_CACHE_SIZE - offset, write_bytes); |
| struct page *page = prepared_pages[pg]; |
| /* |
| * Copy data from userspace to the current page |
| * |
| * Disable pagefault to avoid recursive lock since |
| * the pages are already locked |
| */ |
| pagefault_disable(); |
| copied = iov_iter_copy_from_user_atomic(page, i, offset, count); |
| pagefault_enable(); |
| |
| /* Flush processor's dcache for this page */ |
| flush_dcache_page(page); |
| |
| /* |
| * if we get a partial write, we can end up with |
| * partially up to date pages. These add |
| * a lot of complexity, so make sure they don't |
| * happen by forcing this copy to be retried. |
| * |
| * The rest of the btrfs_file_write code will fall |
| * back to page at a time copies after we return 0. |
| */ |
| if (!PageUptodate(page) && copied < count) |
| copied = 0; |
| |
| iov_iter_advance(i, copied); |
| write_bytes -= copied; |
| total_copied += copied; |
| |
| /* Return to btrfs_file_aio_write to fault page */ |
| if (unlikely(copied == 0)) |
| break; |
| |
| if (unlikely(copied < PAGE_CACHE_SIZE - offset)) { |
| offset += copied; |
| } else { |
| pg++; |
| offset = 0; |
| } |
| } |
| return total_copied; |
| } |
| |
| /* |
| * unlocks pages after btrfs_file_write is done with them |
| */ |
| 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 |
| */ |
| 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. |
| */ |
| int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode, |
| struct page **pages, size_t num_pages, |
| loff_t pos, size_t write_bytes, |
| struct extent_state **cached) |
| { |
| int err = 0; |
| int i; |
| 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, |
| cached); |
| 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 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; |
| u64 gen; |
| 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) { |
| int no_splits = 0; |
| |
| 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); |
| remove_extent_mapping(em_tree, em); |
| if (no_splits) |
| goto next; |
| |
| 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->generation = gen; |
| split->bdev = em->bdev; |
| split->flags = flags; |
| split->compress_type = em->compress_type; |
| ret = add_extent_mapping(em_tree, split); |
| BUG_ON(ret); /* Logic error */ |
| list_move(&split->list, &em_tree->modified_extents); |
| 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; |
| split->compress_type = em->compress_type; |
| split->generation = gen; |
| |
| 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); /* Logic error */ |
| list_move(&split->list, &em_tree->modified_extents); |
| free_extent_map(split); |
| split = NULL; |
| } |
| next: |
| 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) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| struct btrfs_key new_key; |
| u64 ino = btrfs_ino(inode); |
| 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; |
| int modify_tree = -1; |
| int update_refs = (root->ref_cows || root == root->fs_info->tree_root); |
| |
| if (drop_cache) |
| btrfs_drop_extent_cache(inode, start, end - 1, 0); |
| |
| if (start >= BTRFS_I(inode)->disk_i_size) |
| modify_tree = 0; |
| |
| 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; |
| 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 > 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 || !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); |
| 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(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, root, |
| disk_bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| new_key.objectid, |
| start - extent_offset, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| } |
| 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 (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); |
| 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 (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) { |
| 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, |
| root->sectorsize); |
| } else if (update_refs && disk_bytenr > 0) { |
| ret = btrfs_free_extent(trans, root, |
| disk_bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| key.objectid, key.offset - |
| extent_offset, 0); |
| 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, root, ret); |
| break; |
| } |
| |
| del_nr = 0; |
| del_slot = 0; |
| |
| btrfs_release_path(path); |
| continue; |
| } |
| |
| BUG_ON(1); |
| } |
| |
| if (!ret && del_nr > 0) { |
| ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| if (ret) |
| btrfs_abort_transaction(trans, root, ret); |
| } |
| |
| if (drop_end) |
| *drop_end = min(end, extent_end); |
| btrfs_release_path(path); |
| 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); |
| 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; |
| 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]); |
| BUG_ON(key.objectid != 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, |
| 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_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(trans, root, 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, root, 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, root, bytenr, num_bytes, 0, |
| root->root_key.objectid, |
| ino, orig_offset, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| |
| 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, |
| 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, root, bytenr, num_bytes, |
| 0, root->root_key.objectid, |
| ino, orig_offset, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| } |
| 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, root, bytenr, num_bytes, |
| 0, root->root_key.objectid, |
| ino, orig_offset, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| } |
| 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, root, 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 page *page, u64 pos, |
| bool force_uptodate) |
| { |
| int ret = 0; |
| |
| if (((pos & (PAGE_CACHE_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; |
| } |
| } |
| 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, |
| size_t write_bytes, bool force_uptodate) |
| { |
| struct extent_state *cached_state = NULL; |
| int i; |
| unsigned long index = pos >> PAGE_CACHE_SHIFT; |
| struct inode *inode = fdentry(file)->d_inode; |
| gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); |
| int err = 0; |
| int faili = 0; |
| u64 start_pos; |
| u64 last_pos; |
| |
| start_pos = pos & ~((u64)root->sectorsize - 1); |
| last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT; |
| |
| again: |
| for (i = 0; i < num_pages; i++) { |
| 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(pages[i], pos, |
| force_uptodate); |
| if (i == num_pages - 1) |
| err = prepare_uptodate_page(pages[i], |
| pos + write_bytes, false); |
| if (err) { |
| page_cache_release(pages[i]); |
| faili = i - 1; |
| goto fail; |
| } |
| wait_on_page_writeback(pages[i]); |
| } |
| err = 0; |
| if (start_pos < inode->i_size) { |
| struct btrfs_ordered_extent *ordered; |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, |
| start_pos, last_pos - 1, 0, &cached_state); |
| 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_cached(&BTRFS_I(inode)->io_tree, |
| start_pos, last_pos - 1, |
| &cached_state, 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_bit(&BTRFS_I(inode)->io_tree, start_pos, |
| last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC | |
| EXTENT_DO_ACCOUNTING, 0, 0, &cached_state, |
| GFP_NOFS); |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
| start_pos, last_pos - 1, &cached_state, |
| GFP_NOFS); |
| } |
| 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 0; |
| fail: |
| while (faili >= 0) { |
| unlock_page(pages[faili]); |
| page_cache_release(pages[faili]); |
| faili--; |
| } |
| return err; |
| |
| } |
| |
| static noinline ssize_t __btrfs_buffered_write(struct file *file, |
| struct iov_iter *i, |
| loff_t pos) |
| { |
| struct inode *inode = fdentry(file)->d_inode; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct page **pages = NULL; |
| unsigned long first_index; |
| size_t num_written = 0; |
| int nrptrs; |
| int ret = 0; |
| bool force_page_uptodate = false; |
| |
| nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) / |
| PAGE_CACHE_SIZE, PAGE_CACHE_SIZE / |
| (sizeof(struct page *))); |
| nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied); |
| nrptrs = max(nrptrs, 8); |
| pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); |
| if (!pages) |
| return -ENOMEM; |
| |
| first_index = pos >> PAGE_CACHE_SHIFT; |
| |
| while (iov_iter_count(i) > 0) { |
| size_t offset = pos & (PAGE_CACHE_SIZE - 1); |
| size_t write_bytes = min(iov_iter_count(i), |
| nrptrs * (size_t)PAGE_CACHE_SIZE - |
| offset); |
| size_t num_pages = (write_bytes + offset + |
| PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| size_t dirty_pages; |
| size_t copied; |
| |
| WARN_ON(num_pages > nrptrs); |
| |
| /* |
| * 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; |
| } |
| |
| ret = btrfs_delalloc_reserve_space(inode, |
| num_pages << PAGE_CACHE_SHIFT); |
| if (ret) |
| break; |
| |
| /* |
| * This is going to setup the pages array with the number of |
| * pages we want, so we don't really need to worry about the |
| * contents of pages from loop to loop |
| */ |
| ret = prepare_pages(root, file, pages, num_pages, |
| pos, first_index, write_bytes, |
| force_page_uptodate); |
| if (ret) { |
| btrfs_delalloc_release_space(inode, |
| num_pages << PAGE_CACHE_SHIFT); |
| break; |
| } |
| |
| copied = btrfs_copy_from_user(pos, num_pages, |
| write_bytes, pages, i); |
| |
| /* |
| * if we have trouble faulting in the pages, fall |
| * back to one page at a time |
| */ |
| if (copied < write_bytes) |
| nrptrs = 1; |
| |
| if (copied == 0) { |
| force_page_uptodate = true; |
| dirty_pages = 0; |
| } else { |
| force_page_uptodate = false; |
| dirty_pages = (copied + offset + |
| PAGE_CACHE_SIZE - 1) >> |
| PAGE_CACHE_SHIFT; |
| } |
| |
| /* |
| * If we had a short copy we need to release the excess delaloc |
| * bytes we reserved. We need to increment outstanding_extents |
| * because btrfs_delalloc_release_space will decrement it, but |
| * we still have an outstanding extent for the chunk we actually |
| * managed to copy. |
| */ |
| if (num_pages > dirty_pages) { |
| if (copied > 0) { |
| spin_lock(&BTRFS_I(inode)->lock); |
| BTRFS_I(inode)->outstanding_extents++; |
| spin_unlock(&BTRFS_I(inode)->lock); |
| } |
| btrfs_delalloc_release_space(inode, |
| (num_pages - dirty_pages) << |
| PAGE_CACHE_SHIFT); |
| } |
| |
| if (copied > 0) { |
| ret = btrfs_dirty_pages(root, inode, pages, |
| dirty_pages, pos, copied, |
| NULL); |
| if (ret) { |
| btrfs_delalloc_release_space(inode, |
| dirty_pages << PAGE_CACHE_SHIFT); |
| btrfs_drop_pages(pages, num_pages); |
| break; |
| } |
| } |
| |
| btrfs_drop_pages(pages, num_pages); |
| |
| cond_resched(); |
| |
| balance_dirty_pages_ratelimited_nr(inode->i_mapping, |
| dirty_pages); |
| if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1) |
| btrfs_btree_balance_dirty(root, 1); |
| |
| pos += copied; |
| num_written += copied; |
| } |
| |
| kfree(pages); |
| |
| return num_written ? num_written : ret; |
| } |
| |
| static ssize_t __btrfs_direct_write(struct kiocb *iocb, |
| const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos, |
| loff_t *ppos, size_t count, size_t ocount) |
| { |
| struct file *file = iocb->ki_filp; |
| struct iov_iter i; |
| ssize_t written; |
| ssize_t written_buffered; |
| loff_t endbyte; |
| int err; |
| |
| written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos, |
| count, ocount); |
| |
| if (written < 0 || written == count) |
| return written; |
| |
| pos += written; |
| count -= written; |
| iov_iter_init(&i, iov, nr_segs, count, written); |
| written_buffered = __btrfs_buffered_write(file, &i, pos); |
| if (written_buffered < 0) { |
| err = written_buffered; |
| goto out; |
| } |
| endbyte = pos + written_buffered - 1; |
| err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte); |
| if (err) |
| goto out; |
| written += written_buffered; |
| *ppos = pos + written_buffered; |
| invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT, |
| endbyte >> PAGE_CACHE_SHIFT); |
| out: |
| return written ? written : err; |
| } |
| |
| static ssize_t btrfs_file_aio_write(struct kiocb *iocb, |
| const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = fdentry(file)->d_inode; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| loff_t *ppos = &iocb->ki_pos; |
| u64 start_pos; |
| ssize_t num_written = 0; |
| ssize_t err = 0; |
| size_t count, ocount; |
| |
| sb_start_write(inode->i_sb); |
| |
| mutex_lock(&inode->i_mutex); |
| |
| err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); |
| if (err) { |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| count = ocount; |
| |
| current->backing_dev_info = inode->i_mapping->backing_dev_info; |
| err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
| if (err) { |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| |
| if (count == 0) { |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| |
| err = file_remove_suid(file); |
| if (err) { |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| |
| /* |
| * If BTRFS flips readonly due to some impossible error |
| * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR), |
| * although we have opened a file as writable, we have |
| * to stop this write operation to ensure FS consistency. |
| */ |
| if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { |
| mutex_unlock(&inode->i_mutex); |
| err = -EROFS; |
| goto out; |
| } |
| |
| err = file_update_time(file); |
| if (err) { |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| |
| start_pos = round_down(pos, root->sectorsize); |
| if (start_pos > i_size_read(inode)) { |
| err = btrfs_cont_expand(inode, i_size_read(inode), start_pos); |
| if (err) { |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| } |
| |
| if (unlikely(file->f_flags & O_DIRECT)) { |
| num_written = __btrfs_direct_write(iocb, iov, nr_segs, |
| pos, ppos, count, ocount); |
| } else { |
| struct iov_iter i; |
| |
| iov_iter_init(&i, iov, nr_segs, count, num_written); |
| |
| num_written = __btrfs_buffered_write(file, &i, pos); |
| if (num_written > 0) |
| *ppos = pos + num_written; |
| } |
| |
| mutex_unlock(&inode->i_mutex); |
| |
| /* |
| * we want to make sure fsync finds this change |
| * 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 || num_written == -EIOCBQUEUED) { |
| err = generic_write_sync(file, pos, num_written); |
| if (err < 0 && num_written > 0) |
| num_written = err; |
| } |
| out: |
| sb_end_write(inode->i_sb); |
| 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 (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, |
| &BTRFS_I(inode)->runtime_flags)) { |
| 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, loff_t start, loff_t end, int datasync) |
| { |
| struct dentry *dentry = file->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| int ret = 0; |
| struct btrfs_trans_handle *trans; |
| |
| trace_btrfs_sync_file(file, datasync); |
| |
| mutex_lock(&inode->i_mutex); |
| |
| /* |
| * we wait first, since the writeback may change the inode, also wait |
| * ordered range does a filemape_write_and_wait_range which is why we |
| * don't do it above like other file systems. |
| */ |
| root->log_batch++; |
| btrfs_wait_ordered_range(inode, start, end); |
| root->log_batch++; |
| |
| /* |
| * check the transaction that last modified this inode |
| * and see if its already been committed |
| */ |
| if (!BTRFS_I(inode)->last_trans) { |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| |
| /* |
| * if the last transaction that changed this file was before |
| * the current transaction, we can bail out now without any |
| * syncing |
| */ |
| smp_mb(); |
| if (btrfs_inode_in_log(inode, root->fs_info->generation) || |
| BTRFS_I(inode)->last_trans <= |
| root->fs_info->last_trans_committed) { |
| BTRFS_I(inode)->last_trans = 0; |
| |
| /* |
| * We'v 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); |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| |
| /* |
| * ok we haven't committed the transaction yet, lets do a commit |
| */ |
| if (file->private_data) |
| btrfs_ioctl_trans_end(file); |
| |
| trans = btrfs_start_transaction(root, 0); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| mutex_unlock(&inode->i_mutex); |
| goto out; |
| } |
| |
| ret = btrfs_log_dentry_safe(trans, root, dentry); |
| if (ret < 0) { |
| mutex_unlock(&inode->i_mutex); |
| 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(&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); |
| } |
| 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) |
| { |
| struct address_space *mapping = filp->f_mapping; |
| |
| if (!mapping->a_ops->readpage) |
| return -ENOEXEC; |
| |
| file_accessed(filp); |
| vma->vm_ops = &btrfs_file_vm_ops; |
| vma->vm_flags |= VM_CAN_NONLINEAR; |
| |
| return 0; |
| } |
| |
| static int hole_mergeable(struct 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 inode *inode, |
| struct btrfs_path *path, u64 offset, u64 end) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_buffer *leaf; |
| struct btrfs_file_extent_item *fi; |
| struct extent_map *hole_em; |
| struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| struct btrfs_key key; |
| int ret; |
| |
| 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) |
| return ret; |
| BUG_ON(!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]+1, offset, end)) { |
| u64 num_bytes; |
| |
| path->slots[0]++; |
| key.offset = offset; |
| btrfs_set_item_key_safe(trans, root, 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, |
| &BTRFS_I(inode)->runtime_flags); |
| } else { |
| hole_em->start = offset; |
| hole_em->len = end - offset; |
| hole_em->orig_start = offset; |
| |
| hole_em->block_start = EXTENT_MAP_HOLE; |
| hole_em->block_len = 0; |
| hole_em->bdev = root->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); |
| if (!ret) |
| list_move(&hole_em->list, |
| &em_tree->modified_extents); |
| write_unlock(&em_tree->lock); |
| } while (ret == -EEXIST); |
| free_extent_map(hole_em); |
| if (ret) |
| set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| &BTRFS_I(inode)->runtime_flags); |
| } |
| |
| return 0; |
| } |
| |
| static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) |
| { |
| 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 mask = BTRFS_I(inode)->root->sectorsize - 1; |
| u64 lockstart = (offset + mask) & ~mask; |
| u64 lockend = ((offset + len) & ~mask) - 1; |
| u64 cur_offset = lockstart; |
| u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); |
| u64 drop_end; |
| unsigned long nr; |
| int ret = 0; |
| int err = 0; |
| bool same_page = (offset >> PAGE_CACHE_SHIFT) == |
| ((offset + len) >> PAGE_CACHE_SHIFT); |
| |
| btrfs_wait_ordered_range(inode, offset, len); |
| |
| mutex_lock(&inode->i_mutex); |
| if (offset >= inode->i_size) { |
| mutex_unlock(&inode->i_mutex); |
| return 0; |
| } |
| |
| /* |
| * Only do this if we are in the same page and we aren't doing the |
| * entire page. |
| */ |
| if (same_page && len < PAGE_CACHE_SIZE) { |
| ret = btrfs_truncate_page(inode, offset, len, 0); |
| mutex_unlock(&inode->i_mutex); |
| return ret; |
| } |
| |
| /* zero back part of the first page */ |
| ret = btrfs_truncate_page(inode, offset, 0, 0); |
| if (ret) { |
| mutex_unlock(&inode->i_mutex); |
| return ret; |
| } |
| |
| /* zero the front end of the last page */ |
| ret = btrfs_truncate_page(inode, offset + len, 0, 1); |
| if (ret) { |
| mutex_unlock(&inode->i_mutex); |
| return ret; |
| } |
| |
| if (lockend < lockstart) { |
| mutex_unlock(&inode->i_mutex); |
| return 0; |
| } |
| |
| while (1) { |
| struct btrfs_ordered_extent *ordered; |
| |
| truncate_pagecache_range(inode, lockstart, lockend); |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| 0, &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)) && |
| !test_range_bit(&BTRFS_I(inode)->io_tree, lockstart, |
| lockend, EXTENT_UPTODATE, 0, |
| cached_state)) { |
| 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); |
| btrfs_wait_ordered_range(inode, lockstart, |
| lockend - lockstart + 1); |
| } |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); |
| if (!rsv) { |
| ret = -ENOMEM; |
| goto out_free; |
| } |
| rsv->size = btrfs_calc_trunc_metadata_size(root, 1); |
| rsv->failfast = 1; |
| |
| /* |
| * 1 - update the inode |
| * 1 - removing the extents in the range |
| * 1 - adding the hole extent |
| */ |
| trans = btrfs_start_transaction(root, 3); |
| if (IS_ERR(trans)) { |
| err = PTR_ERR(trans); |
| goto out_free; |
| } |
| |
| ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, |
| min_size); |
| BUG_ON(ret); |
| trans->block_rsv = rsv; |
| |
| while (cur_offset < lockend) { |
| ret = __btrfs_drop_extents(trans, root, inode, path, |
| cur_offset, lockend + 1, |
| &drop_end, 1); |
| if (ret != -ENOSPC) |
| break; |
| |
| trans->block_rsv = &root->fs_info->trans_block_rsv; |
| |
| ret = fill_holes(trans, inode, path, cur_offset, drop_end); |
| if (ret) { |
| err = ret; |
| break; |
| } |
| |
| cur_offset = drop_end; |
| |
| ret = btrfs_update_inode(trans, root, inode); |
| if (ret) { |
| err = ret; |
| break; |
| } |
| |
| nr = trans->blocks_used; |
| btrfs_end_transaction(trans, root); |
| btrfs_btree_balance_dirty(root, nr); |
| |
| trans = btrfs_start_transaction(root, 3); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| trans = NULL; |
| break; |
| } |
| |
| ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, |
| rsv, min_size); |
| BUG_ON(ret); /* shouldn't happen */ |
| trans->block_rsv = rsv; |
| } |
| |
| if (ret) { |
| err = ret; |
| goto out_trans; |
| } |
| |
| trans->block_rsv = &root->fs_info->trans_block_rsv; |
| ret = fill_holes(trans, inode, path, cur_offset, drop_end); |
| if (ret) { |
| err = ret; |
| goto out_trans; |
| } |
| |
| out_trans: |
| if (!trans) |
| goto out_free; |
| |
| trans->block_rsv = &root->fs_info->trans_block_rsv; |
| ret = btrfs_update_inode(trans, root, inode); |
| nr = trans->blocks_used; |
| btrfs_end_transaction(trans, root); |
| btrfs_btree_balance_dirty(root, nr); |
| out_free: |
| btrfs_free_path(path); |
| btrfs_free_block_rsv(root, rsv); |
| out: |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| &cached_state, GFP_NOFS); |
| mutex_unlock(&inode->i_mutex); |
| if (ret && !err) |
| err = ret; |
| return err; |
| } |
| |
| static long btrfs_fallocate(struct file *file, int mode, |
| loff_t offset, loff_t len) |
| { |
| struct inode *inode = file->f_path.dentry->d_inode; |
| struct extent_state *cached_state = NULL; |
| u64 cur_offset; |
| u64 last_byte; |
| u64 alloc_start; |
| u64 alloc_end; |
| u64 alloc_hint = 0; |
| u64 locked_end; |
| u64 mask = BTRFS_I(inode)->root->sectorsize - 1; |
| struct extent_map *em; |
| int ret; |
| |
| alloc_start = offset & ~mask; |
| alloc_end = (offset + len + mask) & ~mask; |
| |
| /* 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); |
| |
| /* |
| * Make sure we have enough space before we do the |
| * allocation. |
| */ |
| ret = btrfs_check_data_free_space(inode, len); |
| if (ret) |
| return ret; |
| |
| /* |
| * wait for ordered IO before we have any locks. We'll loop again |
| * below with the locks held. |
| */ |
| btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start); |
| |
| mutex_lock(&inode->i_mutex); |
| ret = inode_newsize_ok(inode, alloc_end); |
| if (ret) |
| goto out; |
| |
| if (alloc_start > inode->i_size) { |
| ret = btrfs_cont_expand(inode, i_size_read(inode), |
| 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, 0, &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_NOFS); |
| /* |
| * we can't wait on the range with the transaction |
| * running or with the extent lock held |
| */ |
| btrfs_wait_ordered_range(inode, alloc_start, |
| alloc_end - alloc_start); |
| } else { |
| if (ordered) |
| btrfs_put_ordered_extent(ordered); |
| break; |
| } |
| } |
| |
| cur_offset = alloc_start; |
| while (1) { |
| u64 actual_end; |
| |
| em = btrfs_get_extent(inode, NULL, 0, cur_offset, |
| alloc_end - cur_offset, 0); |
| if (IS_ERR_OR_NULL(em)) { |
| if (!em) |
| ret = -ENOMEM; |
| else |
| 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 = (last_byte + mask) & ~mask; |
| |
| if (em->block_start == EXTENT_MAP_HOLE || |
| (cur_offset >= inode->i_size && |
| !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { |
| ret = btrfs_prealloc_file_range(inode, mode, cur_offset, |
| last_byte - cur_offset, |
| 1 << inode->i_blkbits, |
| offset + len, |
| &alloc_hint); |
| |
| if (ret < 0) { |
| free_extent_map(em); |
| break; |
| } |
| } else if (actual_end > inode->i_size && |
| !(mode & FALLOC_FL_KEEP_SIZE)) { |
| /* |
| * 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. |
| */ |
| inode->i_ctime = CURRENT_TIME; |
| i_size_write(inode, actual_end); |
| btrfs_ordered_update_i_size(inode, actual_end, NULL); |
| } |
| free_extent_map(em); |
| |
| cur_offset = last_byte; |
| if (cur_offset >= alloc_end) { |
| ret = 0; |
| break; |
| } |
| } |
| unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end, |
| &cached_state, GFP_NOFS); |
| out: |
| mutex_unlock(&inode->i_mutex); |
| /* Let go of our reservation. */ |
| btrfs_free_reserved_data_space(inode, len); |
| return ret; |
| } |
| |
| static int find_desired_extent(struct inode *inode, loff_t *offset, int origin) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_map *em; |
| struct extent_state *cached_state = NULL; |
| u64 lockstart = *offset; |
| u64 lockend = i_size_read(inode); |
| u64 start = *offset; |
| u64 orig_start = *offset; |
| u64 len = i_size_read(inode); |
| u64 last_end = 0; |
| int ret = 0; |
| |
| lockend = max_t(u64, root->sectorsize, lockend); |
| if (lockend <= lockstart) |
| lockend = lockstart + root->sectorsize; |
| |
| len = lockend - lockstart + 1; |
| |
| len = max_t(u64, len, root->sectorsize); |
| if (inode->i_size == 0) |
| return -ENXIO; |
| |
| lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0, |
| &cached_state); |
| |
| /* |
| * Delalloc is such a pain. If we have a hole and we have pending |
| * delalloc for a portion of the hole we will get back a hole that |
| * exists for the entire range since it hasn't been actually written |
| * yet. So to take care of this case we need to look for an extent just |
| * before the position we want in case there is outstanding delalloc |
| * going on here. |
| */ |
| if (origin == SEEK_HOLE && start != 0) { |
| if (start <= root->sectorsize) |
| em = btrfs_get_extent_fiemap(inode, NULL, 0, 0, |
| root->sectorsize, 0); |
| else |
| em = btrfs_get_extent_fiemap(inode, NULL, 0, |
| start - root->sectorsize, |
| root->sectorsize, 0); |
| if (IS_ERR(em)) { |
| ret = PTR_ERR(em); |
| goto out; |
| } |
| last_end = em->start + em->len; |
| if (em->block_start == EXTENT_MAP_DELALLOC) |
| last_end = min_t(u64, last_end, inode->i_size); |
| free_extent_map(em); |
| } |
| |
| while (1) { |
| em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0); |
| if (IS_ERR(em)) { |
| ret = PTR_ERR(em); |
| break; |
| } |
| |
| if (em->block_start == EXTENT_MAP_HOLE) { |
| if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) { |
| if (last_end <= orig_start) { |
| free_extent_map(em); |
| ret = -ENXIO; |
| break; |
| } |
| } |
| |
| if (origin == SEEK_HOLE) { |
| *offset = start; |
| free_extent_map(em); |
| break; |
| } |
| } else { |
| if (origin == SEEK_DATA) { |
| if (em->block_start == EXTENT_MAP_DELALLOC) { |
| if (start >= inode->i_size) { |
| free_extent_map(em); |
| ret = -ENXIO; |
| break; |
| } |
| } |
| |
| *offset = start; |
| free_extent_map(em); |
| break; |
| } |
| } |
| |
| start = em->start + em->len; |
| last_end = em->start + em->len; |
| |
| if (em->block_start == EXTENT_MAP_DELALLOC) |
| last_end = min_t(u64, last_end, inode->i_size); |
| |
| if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) { |
| free_extent_map(em); |
| ret = -ENXIO; |
| break; |
| } |
| free_extent_map(em); |
| cond_resched(); |
| } |
| if (!ret) |
| *offset = min(*offset, inode->i_size); |
| out: |
| 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 origin) |
| { |
| struct inode *inode = file->f_mapping->host; |
| int ret; |
| |
| mutex_lock(&inode->i_mutex); |
| switch (origin) { |
| case SEEK_END: |
| case SEEK_CUR: |
| offset = generic_file_llseek(file, offset, origin); |
| goto out; |
| case SEEK_DATA: |
| case SEEK_HOLE: |
| if (offset >= i_size_read(inode)) { |
| mutex_unlock(&inode->i_mutex); |
| return -ENXIO; |
| } |
| |
| ret = find_desired_extent(inode, &offset, origin); |
| if (ret) { |
| mutex_unlock(&inode->i_mutex); |
| return ret; |
| } |
| } |
| |
| if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) { |
| offset = -EINVAL; |
| goto out; |
| } |
| if (offset > inode->i_sb->s_maxbytes) { |
| offset = -EINVAL; |
| goto out; |
| } |
| |
| /* Special lock needed here? */ |
| if (offset != file->f_pos) { |
| file->f_pos = offset; |
| file->f_version = 0; |
| } |
| out: |
| mutex_unlock(&inode->i_mutex); |
| return offset; |
| } |
| |
| const struct file_operations btrfs_file_operations = { |
| .llseek = btrfs_file_llseek, |
| .read = do_sync_read, |
| .write = do_sync_write, |
| .aio_read = generic_file_aio_read, |
| .splice_read = generic_file_splice_read, |
| .aio_write = btrfs_file_aio_write, |
| .mmap = btrfs_file_mmap, |
| .open = generic_file_open, |
| .release = btrfs_release_file, |
| .fsync = btrfs_sync_file, |
| .fallocate = btrfs_fallocate, |
| .unlocked_ioctl = btrfs_ioctl, |
| #ifdef CONFIG_COMPAT |
| .compat_ioctl = btrfs_ioctl, |
| #endif |
| }; |