From 9ed74f2dba6ebf9f30b80554290bfc73cc3ef083 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 11 Sep 2009 16:12:44 -0400 Subject: Btrfs: proper -ENOSPC handling At the start of a transaction we do a btrfs_reserve_metadata_space() and specify how many items we plan on modifying. Then once we've done our modifications and such, just call btrfs_unreserve_metadata_space() for the same number of items we reserved. For keeping track of metadata needed for data I've had to add an extent_io op for when we merge extents. This lets us track space properly when we are doing sequential writes, so we don't end up reserving way more metadata space than what we need. The only place where the metadata space accounting is not done is in the relocation code. This is because Yan is going to be reworking that code in the near future, so running btrfs-vol -b could still possibly result in a ENOSPC related panic. This patch also turns off the metadata_ratio stuff in order to allow users to more efficiently use their disk space. This patch makes it so we track how much metadata we need for an inode's delayed allocation extents by tracking how many extents are currently waiting for allocation. It introduces two new callbacks for the extent_io tree's, merge_extent_hook and split_extent_hook. These help us keep track of when we merge delalloc extents together and split them up. Reservations are handled prior to any actually dirty'ing occurs, and then we unreserve after we dirty. btrfs_unreserve_metadata_for_delalloc() will make the appropriate unreservations as needed based on the number of reservations we currently have and the number of extents we currently have. Doing the reservation outside of doing any of the actual dirty'ing lets us do things like filemap_flush() the inode to try and force delalloc to happen, or as a last resort actually start allocation on all delalloc inodes in the fs. This has survived dbench, fs_mark and an fsx torture test. Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 193 insertions(+), 31 deletions(-) (limited to 'fs/btrfs/inode.c') diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 01c5f8b5a34..3cc5677f544 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1159,6 +1159,83 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page, return ret; } +static int btrfs_split_extent_hook(struct inode *inode, + struct extent_state *orig, u64 split) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 size; + + if (!(orig->state & EXTENT_DELALLOC)) + return 0; + + size = orig->end - orig->start + 1; + if (size > root->fs_info->max_extent) { + u64 num_extents; + u64 new_size; + + new_size = orig->end - split + 1; + num_extents = div64_u64(size + root->fs_info->max_extent - 1, + root->fs_info->max_extent); + + /* + * if we break a large extent up then leave delalloc_extents be, + * since we've already accounted for the large extent. + */ + if (div64_u64(new_size + root->fs_info->max_extent - 1, + root->fs_info->max_extent) < num_extents) + return 0; + } + + BTRFS_I(inode)->delalloc_extents++; + + return 0; +} + +/* + * extent_io.c merge_extent_hook, used to track merged delayed allocation + * extents so we can keep track of new extents that are just merged onto old + * extents, such as when we are doing sequential writes, so we can properly + * account for the metadata space we'll need. + */ +static int btrfs_merge_extent_hook(struct inode *inode, + struct extent_state *new, + struct extent_state *other) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 new_size, old_size; + u64 num_extents; + + /* not delalloc, ignore it */ + if (!(other->state & EXTENT_DELALLOC)) + return 0; + + old_size = other->end - other->start + 1; + if (new->start < other->start) + new_size = other->end - new->start + 1; + else + new_size = new->end - other->start + 1; + + /* we're not bigger than the max, unreserve the space and go */ + if (new_size <= root->fs_info->max_extent) { + BTRFS_I(inode)->delalloc_extents--; + return 0; + } + + /* + * If we grew by another max_extent, just return, we want to keep that + * reserved amount. + */ + num_extents = div64_u64(old_size + root->fs_info->max_extent - 1, + root->fs_info->max_extent); + if (div64_u64(new_size + root->fs_info->max_extent - 1, + root->fs_info->max_extent) > num_extents) + return 0; + + BTRFS_I(inode)->delalloc_extents--; + + return 0; +} + /* * extent_io.c set_bit_hook, used to track delayed allocation * bytes in this file, and to maintain the list of inodes that @@ -1167,6 +1244,7 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page, static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end, unsigned long old, unsigned long bits) { + /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testeing for the DELALLOC @@ -1174,6 +1252,8 @@ static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end, */ if (!(old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; + + BTRFS_I(inode)->delalloc_extents++; btrfs_delalloc_reserve_space(root, inode, end - start + 1); spin_lock(&root->fs_info->delalloc_lock); BTRFS_I(inode)->delalloc_bytes += end - start + 1; @@ -1190,22 +1270,27 @@ static int btrfs_set_bit_hook(struct inode *inode, u64 start, u64 end, /* * extent_io.c clear_bit_hook, see set_bit_hook for why */ -static int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end, - unsigned long old, unsigned long bits) +static int btrfs_clear_bit_hook(struct inode *inode, + struct extent_state *state, unsigned long bits) { /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testeing for the DELALLOC * bit, which is only set or cleared with irqs on */ - if ((old & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { + if ((state->state & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; + BTRFS_I(inode)->delalloc_extents--; + btrfs_unreserve_metadata_for_delalloc(root, inode, 1); + spin_lock(&root->fs_info->delalloc_lock); - if (end - start + 1 > root->fs_info->delalloc_bytes) { + if (state->end - state->start + 1 > + root->fs_info->delalloc_bytes) { printk(KERN_INFO "btrfs warning: delalloc account " "%llu %llu\n", - (unsigned long long)end - start + 1, + (unsigned long long) + state->end - state->start + 1, (unsigned long long) root->fs_info->delalloc_bytes); btrfs_delalloc_free_space(root, inode, (u64)-1); @@ -1213,9 +1298,12 @@ static int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end, BTRFS_I(inode)->delalloc_bytes = 0; } else { btrfs_delalloc_free_space(root, inode, - end - start + 1); - root->fs_info->delalloc_bytes -= end - start + 1; - BTRFS_I(inode)->delalloc_bytes -= end - start + 1; + state->end - + state->start + 1); + root->fs_info->delalloc_bytes -= state->end - + state->start + 1; + BTRFS_I(inode)->delalloc_bytes -= state->end - + state->start + 1; } if (BTRFS_I(inode)->delalloc_bytes == 0 && !list_empty(&BTRFS_I(inode)->delalloc_inodes)) { @@ -2950,7 +3038,12 @@ again: goto again; } - btrfs_set_extent_delalloc(inode, page_start, page_end); + ret = btrfs_set_extent_delalloc(inode, page_start, page_end); + if (ret) { + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + goto out_unlock; + } + ret = 0; if (offset != PAGE_CACHE_SIZE) { kaddr = kmap(page); @@ -2981,15 +3074,11 @@ int btrfs_cont_expand(struct inode *inode, loff_t size) u64 last_byte; u64 cur_offset; u64 hole_size; - int err; + int err = 0; if (size <= hole_start) return 0; - err = btrfs_check_metadata_free_space(root); - if (err) - return err; - btrfs_truncate_page(inode->i_mapping, inode->i_size); while (1) { @@ -3024,12 +3113,18 @@ int btrfs_cont_expand(struct inode *inode, loff_t size) cur_offset, &hint_byte, 1); if (err) break; + + err = btrfs_reserve_metadata_space(root, 1); + if (err) + break; + err = btrfs_insert_file_extent(trans, root, inode->i_ino, cur_offset, 0, 0, hole_size, 0, hole_size, 0, 0, 0); btrfs_drop_extent_cache(inode, hole_start, last_byte - 1, 0); + btrfs_unreserve_metadata_space(root, 1); } free_extent_map(em); cur_offset = last_byte; @@ -3990,11 +4085,18 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry, if (!new_valid_dev(rdev)) return -EINVAL; - err = btrfs_check_metadata_free_space(root); + /* + * 2 for inode item and ref + * 2 for dir items + * 1 for xattr if selinux is on + */ + err = btrfs_reserve_metadata_space(root, 5); if (err) - goto fail; + return err; trans = btrfs_start_transaction(root, 1); + if (!trans) + goto fail; btrfs_set_trans_block_group(trans, dir); err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); @@ -4032,6 +4134,7 @@ out_unlock: nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); fail: + btrfs_unreserve_metadata_space(root, 5); if (drop_inode) { inode_dec_link_count(inode); iput(inode); @@ -4052,10 +4155,18 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry, u64 objectid; u64 index = 0; - err = btrfs_check_metadata_free_space(root); + /* + * 2 for inode item and ref + * 2 for dir items + * 1 for xattr if selinux is on + */ + err = btrfs_reserve_metadata_space(root, 5); if (err) - goto fail; + return err; + trans = btrfs_start_transaction(root, 1); + if (!trans) + goto fail; btrfs_set_trans_block_group(trans, dir); err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); @@ -4096,6 +4207,7 @@ out_unlock: nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); fail: + btrfs_unreserve_metadata_space(root, 5); if (drop_inode) { inode_dec_link_count(inode); iput(inode); @@ -4118,10 +4230,16 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, if (inode->i_nlink == 0) return -ENOENT; - btrfs_inc_nlink(inode); - err = btrfs_check_metadata_free_space(root); + /* + * 1 item for inode ref + * 2 items for dir items + */ + err = btrfs_reserve_metadata_space(root, 3); if (err) - goto fail; + return err; + + btrfs_inc_nlink(inode); + err = btrfs_set_inode_index(dir, &index); if (err) goto fail; @@ -4145,6 +4263,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); fail: + btrfs_unreserve_metadata_space(root, 3); if (drop_inode) { inode_dec_link_count(inode); iput(inode); @@ -4164,17 +4283,21 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) u64 index = 0; unsigned long nr = 1; - err = btrfs_check_metadata_free_space(root); + /* + * 2 items for inode and ref + * 2 items for dir items + * 1 for xattr if selinux is on + */ + err = btrfs_reserve_metadata_space(root, 5); if (err) - goto out_unlock; + return err; trans = btrfs_start_transaction(root, 1); - btrfs_set_trans_block_group(trans, dir); - - if (IS_ERR(trans)) { - err = PTR_ERR(trans); + if (!trans) { + err = -ENOMEM; goto out_unlock; } + btrfs_set_trans_block_group(trans, dir); err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); if (err) { @@ -4223,6 +4346,7 @@ out_fail: btrfs_end_transaction_throttle(trans, root); out_unlock: + btrfs_unreserve_metadata_space(root, 5); if (drop_on_err) iput(inode); btrfs_btree_balance_dirty(root, nr); @@ -4747,6 +4871,13 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) goto out; } + ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1); + if (ret) { + btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE); + ret = VM_FAULT_SIGBUS; + goto out; + } + ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ again: lock_page(page); @@ -4778,7 +4909,12 @@ again: goto again; } - btrfs_set_extent_delalloc(inode, page_start, page_end); + ret = btrfs_set_extent_delalloc(inode, page_start, page_end); + if (ret) { + unlock_extent(io_tree, page_start, page_end, GFP_NOFS); + ret = VM_FAULT_SIGBUS; + goto out_unlock; + } ret = 0; /* page is wholly or partially inside EOF */ @@ -4801,6 +4937,7 @@ again: unlock_extent(io_tree, page_start, page_end, GFP_NOFS); out_unlock: + btrfs_unreserve_metadata_for_delalloc(root, inode, 1); if (!ret) return VM_FAULT_LOCKED; unlock_page(page); @@ -4917,6 +5054,8 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) return NULL; ei->last_trans = 0; ei->logged_trans = 0; + ei->delalloc_extents = 0; + ei->delalloc_reserved_extents = 0; btrfs_ordered_inode_tree_init(&ei->ordered_tree); INIT_LIST_HEAD(&ei->i_orphan); INIT_LIST_HEAD(&ei->ordered_operations); @@ -5070,7 +5209,12 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) return -ENOTEMPTY; - ret = btrfs_check_metadata_free_space(root); + /* + * 2 items for dir items + * 1 item for orphan entry + * 1 item for ref + */ + ret = btrfs_reserve_metadata_space(root, 4); if (ret) return ret; @@ -5185,6 +5329,8 @@ out_fail: if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) up_read(&root->fs_info->subvol_sem); + + btrfs_unreserve_metadata_space(root, 4); return ret; } @@ -5256,11 +5402,18 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry, if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) return -ENAMETOOLONG; - err = btrfs_check_metadata_free_space(root); + /* + * 2 items for inode item and ref + * 2 items for dir items + * 1 item for xattr if selinux is on + */ + err = btrfs_reserve_metadata_space(root, 5); if (err) - goto out_fail; + return err; trans = btrfs_start_transaction(root, 1); + if (!trans) + goto out_fail; btrfs_set_trans_block_group(trans, dir); err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); @@ -5341,6 +5494,7 @@ out_unlock: nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); out_fail: + btrfs_unreserve_metadata_space(root, 5); if (drop_inode) { inode_dec_link_count(inode); iput(inode); @@ -5362,6 +5516,11 @@ static int prealloc_file_range(struct btrfs_trans_handle *trans, while (num_bytes > 0) { alloc_size = min(num_bytes, root->fs_info->max_extent); + + ret = btrfs_reserve_metadata_space(root, 1); + if (ret) + goto out; + ret = btrfs_reserve_extent(trans, root, alloc_size, root->sectorsize, 0, alloc_hint, (u64)-1, &ins, 1); @@ -5381,6 +5540,7 @@ static int prealloc_file_range(struct btrfs_trans_handle *trans, num_bytes -= ins.offset; cur_offset += ins.offset; alloc_hint = ins.objectid + ins.offset; + btrfs_unreserve_metadata_space(root, 1); } out: if (cur_offset > start) { @@ -5566,6 +5726,8 @@ static struct extent_io_ops btrfs_extent_io_ops = { .readpage_io_failed_hook = btrfs_io_failed_hook, .set_bit_hook = btrfs_set_bit_hook, .clear_bit_hook = btrfs_clear_bit_hook, + .merge_extent_hook = btrfs_merge_extent_hook, + .split_extent_hook = btrfs_split_extent_hook, }; /* -- cgit v1.2.3 From fbf190874407f23d2891b53ffdf7d3c6be8d47ff Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 1 Oct 2009 17:10:23 -0400 Subject: Btrfs: fix data space leak fix There is a problem where page_mkwrite can be called on a dirtied page that already has a delalloc range associated with it. The fix is to clear any delalloc bits for the range we are dirtying so the space accounting gets handled properly. This is the same thing we do in the normal write case, so we are consistent across the board. With this patch we no longer leak reserved space. Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'fs/btrfs/inode.c') diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 3cc5677f544..3a6f953337b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4909,10 +4909,21 @@ again: goto again; } + /* + * XXX - page_mkwrite gets called every time the page is dirtied, even + * if it was already dirty, so for space accounting reasons we need to + * clear any delalloc bits for the range we are fixing to save. There + * is probably a better way to do this, but for now keep consistent with + * prepare_pages in the normal write path. + */ + clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, + EXTENT_DIRTY | EXTENT_DELALLOC, GFP_NOFS); + ret = btrfs_set_extent_delalloc(inode, page_start, page_end); if (ret) { unlock_extent(io_tree, page_start, page_end, GFP_NOFS); ret = VM_FAULT_SIGBUS; + btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE); goto out_unlock; } ret = 0; -- cgit v1.2.3