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author | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
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committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
commit | 15dfd0df63ce6847081d09b2bbd567cc0cc4eae1 (patch) | |
tree | 3b73f24fcef970bfcace3cbb297cfa57f3994682 /fs/btrfs | |
parent | 328aa7a45af61bc0060c80847daa67fef7b9c0d0 (diff) | |
parent | 0149138c4142da287d23f9d5c6038f7fb5e30ac2 (diff) | |
download | kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.zip kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.gz kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.bz2 |
initial merge with 3.2.72
Diffstat (limited to 'fs/btrfs')
-rw-r--r-- | fs/btrfs/backref.c | 776 | ||||
-rw-r--r-- | fs/btrfs/backref.h | 62 | ||||
-rw-r--r-- | fs/btrfs/reada.c | 951 |
3 files changed, 1789 insertions, 0 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c new file mode 100644 index 0000000..22c64ff --- /dev/null +++ b/fs/btrfs/backref.c @@ -0,0 +1,776 @@ +/* + * Copyright (C) 2011 STRATO. 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 "ctree.h" +#include "disk-io.h" +#include "backref.h" + +struct __data_ref { + struct list_head list; + u64 inum; + u64 root; + u64 extent_data_item_offset; +}; + +struct __shared_ref { + struct list_head list; + u64 disk_byte; +}; + +static int __inode_info(u64 inum, u64 ioff, u8 key_type, + struct btrfs_root *fs_root, struct btrfs_path *path, + struct btrfs_key *found_key) +{ + int ret; + struct btrfs_key key; + struct extent_buffer *eb; + + key.type = key_type; + key.objectid = inum; + key.offset = ioff; + + ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); + if (ret < 0) + return ret; + + eb = path->nodes[0]; + if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(fs_root, path); + if (ret) + return ret; + eb = path->nodes[0]; + } + + btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); + if (found_key->type != key.type || found_key->objectid != key.objectid) + return 1; + + return 0; +} + +/* + * this makes the path point to (inum INODE_ITEM ioff) + */ +int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, + struct btrfs_path *path) +{ + struct btrfs_key key; + return __inode_info(inum, ioff, BTRFS_INODE_ITEM_KEY, fs_root, path, + &key); +} + +static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, + struct btrfs_path *path, + struct btrfs_key *found_key) +{ + return __inode_info(inum, ioff, BTRFS_INODE_REF_KEY, fs_root, path, + found_key); +} + +/* + * this iterates to turn a btrfs_inode_ref into a full filesystem path. elements + * of the path are separated by '/' and the path is guaranteed to be + * 0-terminated. the path is only given within the current file system. + * Therefore, it never starts with a '/'. the caller is responsible to provide + * "size" bytes in "dest". the dest buffer will be filled backwards. finally, + * the start point of the resulting string is returned. this pointer is within + * dest, normally. + * in case the path buffer would overflow, the pointer is decremented further + * as if output was written to the buffer, though no more output is actually + * generated. that way, the caller can determine how much space would be + * required for the path to fit into the buffer. in that case, the returned + * value will be smaller than dest. callers must check this! + */ +static char *iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, + struct btrfs_inode_ref *iref, + struct extent_buffer *eb_in, u64 parent, + char *dest, u32 size) +{ + u32 len; + int slot; + u64 next_inum; + int ret; + s64 bytes_left = size - 1; + struct extent_buffer *eb = eb_in; + struct btrfs_key found_key; + + if (bytes_left >= 0) + dest[bytes_left] = '\0'; + + while (1) { + len = btrfs_inode_ref_name_len(eb, iref); + bytes_left -= len; + if (bytes_left >= 0) + read_extent_buffer(eb, dest + bytes_left, + (unsigned long)(iref + 1), len); + if (eb != eb_in) + free_extent_buffer(eb); + ret = inode_ref_info(parent, 0, fs_root, path, &found_key); + if (ret) + break; + next_inum = found_key.offset; + + /* regular exit ahead */ + if (parent == next_inum) + break; + + slot = path->slots[0]; + eb = path->nodes[0]; + /* make sure we can use eb after releasing the path */ + if (eb != eb_in) + atomic_inc(&eb->refs); + btrfs_release_path(path); + + iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); + parent = next_inum; + --bytes_left; + if (bytes_left >= 0) + dest[bytes_left] = '/'; + } + + btrfs_release_path(path); + + if (ret) + return ERR_PTR(ret); + + return dest + bytes_left; +} + +/* + * this makes the path point to (logical EXTENT_ITEM *) + * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for + * tree blocks and <0 on error. + */ +int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, + struct btrfs_path *path, struct btrfs_key *found_key) +{ + int ret; + u64 flags; + u32 item_size; + struct extent_buffer *eb; + struct btrfs_extent_item *ei; + struct btrfs_key key; + + key.type = BTRFS_EXTENT_ITEM_KEY; + key.objectid = logical; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); + if (ret < 0) + return ret; + ret = btrfs_previous_item(fs_info->extent_root, path, + 0, BTRFS_EXTENT_ITEM_KEY); + if (ret < 0) + return ret; + + btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]); + if (found_key->type != BTRFS_EXTENT_ITEM_KEY || + found_key->objectid > logical || + found_key->objectid + found_key->offset <= logical) + return -ENOENT; + + eb = path->nodes[0]; + item_size = btrfs_item_size_nr(eb, path->slots[0]); + BUG_ON(item_size < sizeof(*ei)); + + ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); + flags = btrfs_extent_flags(eb, ei); + + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) + return BTRFS_EXTENT_FLAG_TREE_BLOCK; + if (flags & BTRFS_EXTENT_FLAG_DATA) + return BTRFS_EXTENT_FLAG_DATA; + + return -EIO; +} + +/* + * helper function to iterate extent inline refs. ptr must point to a 0 value + * for the first call and may be modified. it is used to track state. + * if more refs exist, 0 is returned and the next call to + * __get_extent_inline_ref must pass the modified ptr parameter to get the + * next ref. after the last ref was processed, 1 is returned. + * returns <0 on error + */ +static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb, + struct btrfs_extent_item *ei, u32 item_size, + struct btrfs_extent_inline_ref **out_eiref, + int *out_type) +{ + unsigned long end; + u64 flags; + struct btrfs_tree_block_info *info; + + if (!*ptr) { + /* first call */ + flags = btrfs_extent_flags(eb, ei); + if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + info = (struct btrfs_tree_block_info *)(ei + 1); + *out_eiref = + (struct btrfs_extent_inline_ref *)(info + 1); + } else { + *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1); + } + *ptr = (unsigned long)*out_eiref; + if ((void *)*ptr >= (void *)ei + item_size) + return -ENOENT; + } + + end = (unsigned long)ei + item_size; + *out_eiref = (struct btrfs_extent_inline_ref *)*ptr; + *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref); + + *ptr += btrfs_extent_inline_ref_size(*out_type); + WARN_ON(*ptr > end); + if (*ptr == end) + return 1; /* last */ + + return 0; +} + +/* + * reads the tree block backref for an extent. tree level and root are returned + * through out_level and out_root. ptr must point to a 0 value for the first + * call and may be modified (see __get_extent_inline_ref comment). + * returns 0 if data was provided, 1 if there was no more data to provide or + * <0 on error. + */ +int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, + struct btrfs_extent_item *ei, u32 item_size, + u64 *out_root, u8 *out_level) +{ + int ret; + int type; + struct btrfs_tree_block_info *info; + struct btrfs_extent_inline_ref *eiref; + + if (*ptr == (unsigned long)-1) + return 1; + + while (1) { + ret = __get_extent_inline_ref(ptr, eb, ei, item_size, + &eiref, &type); + if (ret < 0) + return ret; + + if (type == BTRFS_TREE_BLOCK_REF_KEY || + type == BTRFS_SHARED_BLOCK_REF_KEY) + break; + + if (ret == 1) + return 1; + } + + /* we can treat both ref types equally here */ + info = (struct btrfs_tree_block_info *)(ei + 1); + *out_root = btrfs_extent_inline_ref_offset(eb, eiref); + *out_level = btrfs_tree_block_level(eb, info); + + if (ret == 1) + *ptr = (unsigned long)-1; + + return 0; +} + +static int __data_list_add(struct list_head *head, u64 inum, + u64 extent_data_item_offset, u64 root) +{ + struct __data_ref *ref; + + ref = kmalloc(sizeof(*ref), GFP_NOFS); + if (!ref) + return -ENOMEM; + + ref->inum = inum; + ref->extent_data_item_offset = extent_data_item_offset; + ref->root = root; + list_add_tail(&ref->list, head); + + return 0; +} + +static int __data_list_add_eb(struct list_head *head, struct extent_buffer *eb, + struct btrfs_extent_data_ref *dref) +{ + return __data_list_add(head, btrfs_extent_data_ref_objectid(eb, dref), + btrfs_extent_data_ref_offset(eb, dref), + btrfs_extent_data_ref_root(eb, dref)); +} + +static int __shared_list_add(struct list_head *head, u64 disk_byte) +{ + struct __shared_ref *ref; + + ref = kmalloc(sizeof(*ref), GFP_NOFS); + if (!ref) + return -ENOMEM; + + ref->disk_byte = disk_byte; + list_add_tail(&ref->list, head); + + return 0; +} + +static int __iter_shared_inline_ref_inodes(struct btrfs_fs_info *fs_info, + u64 logical, u64 inum, + u64 extent_data_item_offset, + u64 extent_offset, + struct btrfs_path *path, + struct list_head *data_refs, + iterate_extent_inodes_t *iterate, + void *ctx) +{ + u64 ref_root; + u32 item_size; + struct btrfs_key key; + struct extent_buffer *eb; + struct btrfs_extent_item *ei; + struct btrfs_extent_inline_ref *eiref; + struct __data_ref *ref; + int ret; + int type; + int last; + unsigned long ptr = 0; + + WARN_ON(!list_empty(data_refs)); + ret = extent_from_logical(fs_info, logical, path, &key); + if (ret & BTRFS_EXTENT_FLAG_DATA) + ret = -EIO; + if (ret < 0) + goto out; + + eb = path->nodes[0]; + ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); + item_size = btrfs_item_size_nr(eb, path->slots[0]); + + ret = 0; + ref_root = 0; + /* + * as done in iterate_extent_inodes, we first build a list of refs to + * iterate, then free the path and then iterate them to avoid deadlocks. + */ + do { + last = __get_extent_inline_ref(&ptr, eb, ei, item_size, + &eiref, &type); + if (last < 0) { + ret = last; + goto out; + } + if (type == BTRFS_TREE_BLOCK_REF_KEY || + type == BTRFS_SHARED_BLOCK_REF_KEY) { + ref_root = btrfs_extent_inline_ref_offset(eb, eiref); + ret = __data_list_add(data_refs, inum, + extent_data_item_offset, + ref_root); + } + } while (!ret && !last); + + btrfs_release_path(path); + + if (ref_root == 0) { + printk(KERN_ERR "btrfs: failed to find tree block ref " + "for shared data backref %llu\n", logical); + WARN_ON(1); + ret = -EIO; + } + +out: + while (!list_empty(data_refs)) { + ref = list_first_entry(data_refs, struct __data_ref, list); + list_del(&ref->list); + if (!ret) + ret = iterate(ref->inum, extent_offset + + ref->extent_data_item_offset, + ref->root, ctx); + kfree(ref); + } + + return ret; +} + +static int __iter_shared_inline_ref(struct btrfs_fs_info *fs_info, + u64 logical, u64 orig_extent_item_objectid, + u64 extent_offset, struct btrfs_path *path, + struct list_head *data_refs, + iterate_extent_inodes_t *iterate, + void *ctx) +{ + u64 disk_byte; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + struct extent_buffer *eb; + int slot; + int nritems; + int ret; + int found = 0; + + eb = read_tree_block(fs_info->tree_root, logical, + fs_info->tree_root->leafsize, 0); + if (!eb) + return -EIO; + + /* + * from the shared data ref, we only have the leaf but we need + * the key. thus, we must look into all items and see that we + * find one (some) with a reference to our extent item. + */ + nritems = btrfs_header_nritems(eb); + for (slot = 0; slot < nritems; ++slot) { + btrfs_item_key_to_cpu(eb, &key, slot); + if (key.type != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); + if (!fi) { + free_extent_buffer(eb); + return -EIO; + } + disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); + if (disk_byte != orig_extent_item_objectid) { + if (found) + break; + else + continue; + } + ++found; + ret = __iter_shared_inline_ref_inodes(fs_info, logical, + key.objectid, + key.offset, + extent_offset, path, + data_refs, + iterate, ctx); + if (ret) + break; + } + + if (!found) { + printk(KERN_ERR "btrfs: failed to follow shared data backref " + "to parent %llu\n", logical); + WARN_ON(1); + ret = -EIO; + } + + free_extent_buffer(eb); + return ret; +} + +/* + * calls iterate() for every inode that references the extent identified by + * the given parameters. will use the path given as a parameter and return it + * released. + * when the iterator function returns a non-zero value, iteration stops. + */ +int iterate_extent_inodes(struct btrfs_fs_info *fs_info, + struct btrfs_path *path, + u64 extent_item_objectid, + u64 extent_offset, + iterate_extent_inodes_t *iterate, void *ctx) +{ + unsigned long ptr = 0; + int last; + int ret; + int type; + u64 logical; + u32 item_size; + struct btrfs_extent_inline_ref *eiref; + struct btrfs_extent_data_ref *dref; + struct extent_buffer *eb; + struct btrfs_extent_item *ei; + struct btrfs_key key; + struct list_head data_refs = LIST_HEAD_INIT(data_refs); + struct list_head shared_refs = LIST_HEAD_INIT(shared_refs); + struct __data_ref *ref_d; + struct __shared_ref *ref_s; + + eb = path->nodes[0]; + ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); + item_size = btrfs_item_size_nr(eb, path->slots[0]); + + /* first we iterate the inline refs, ... */ + do { + last = __get_extent_inline_ref(&ptr, eb, ei, item_size, + &eiref, &type); + if (last == -ENOENT) { + ret = 0; + break; + } + if (last < 0) { + ret = last; + break; + } + + if (type == BTRFS_EXTENT_DATA_REF_KEY) { + dref = (struct btrfs_extent_data_ref *)(&eiref->offset); + ret = __data_list_add_eb(&data_refs, eb, dref); + } else if (type == BTRFS_SHARED_DATA_REF_KEY) { + logical = btrfs_extent_inline_ref_offset(eb, eiref); + ret = __shared_list_add(&shared_refs, logical); + } + } while (!ret && !last); + + /* ... then we proceed to in-tree references and ... */ + while (!ret) { + ++path->slots[0]; + if (path->slots[0] > btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(fs_info->extent_root, path); + if (ret) { + if (ret == 1) + ret = 0; /* we're done */ + break; + } + eb = path->nodes[0]; + } + btrfs_item_key_to_cpu(eb, &key, path->slots[0]); + if (key.objectid != extent_item_objectid) + break; + if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { + dref = btrfs_item_ptr(eb, path->slots[0], + struct btrfs_extent_data_ref); + ret = __data_list_add_eb(&data_refs, eb, dref); + } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { + ret = __shared_list_add(&shared_refs, key.offset); + } + } + + btrfs_release_path(path); + + /* + * ... only at the very end we can process the refs we found. this is + * because the iterator function we call is allowed to make tree lookups + * and we have to avoid deadlocks. additionally, we need more tree + * lookups ourselves for shared data refs. + */ + while (!list_empty(&data_refs)) { + ref_d = list_first_entry(&data_refs, struct __data_ref, list); + list_del(&ref_d->list); + if (!ret) + ret = iterate(ref_d->inum, extent_offset + + ref_d->extent_data_item_offset, + ref_d->root, ctx); + kfree(ref_d); + } + + while (!list_empty(&shared_refs)) { + ref_s = list_first_entry(&shared_refs, struct __shared_ref, + list); + list_del(&ref_s->list); + if (!ret) + ret = __iter_shared_inline_ref(fs_info, + ref_s->disk_byte, + extent_item_objectid, + extent_offset, path, + &data_refs, + iterate, ctx); + kfree(ref_s); + } + + return ret; +} + +int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, + struct btrfs_path *path, + iterate_extent_inodes_t *iterate, void *ctx) +{ + int ret; + u64 offset; + struct btrfs_key found_key; + + ret = extent_from_logical(fs_info, logical, path, + &found_key); + if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) + ret = -EINVAL; + if (ret < 0) + return ret; + + offset = logical - found_key.objectid; + ret = iterate_extent_inodes(fs_info, path, found_key.objectid, + offset, iterate, ctx); + + return ret; +} + +static int iterate_irefs(u64 inum, struct btrfs_root *fs_root, + struct btrfs_path *path, + iterate_irefs_t *iterate, void *ctx) +{ + int ret; + int slot; + u32 cur; + u32 len; + u32 name_len; + u64 parent = 0; + int found = 0; + struct extent_buffer *eb; + struct btrfs_item *item; + struct btrfs_inode_ref *iref; + struct btrfs_key found_key; + + while (1) { + ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path, + &found_key); + if (ret < 0) + break; + if (ret) { + ret = found ? 0 : -ENOENT; + break; + } + ++found; + + parent = found_key.offset; + slot = path->slots[0]; + eb = path->nodes[0]; + /* make sure we can use eb after releasing the path */ + atomic_inc(&eb->refs); + btrfs_release_path(path); + + item = btrfs_item_nr(eb, slot); + iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); + + for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { + name_len = btrfs_inode_ref_name_len(eb, iref); + /* path must be released before calling iterate()! */ + ret = iterate(parent, iref, eb, ctx); + if (ret) { + free_extent_buffer(eb); + break; + } + len = sizeof(*iref) + name_len; + iref = (struct btrfs_inode_ref *)((char *)iref + len); + } + free_extent_buffer(eb); + } + + btrfs_release_path(path); + + return ret; +} + +/* + * returns 0 if the path could be dumped (probably truncated) + * returns <0 in case of an error + */ +static int inode_to_path(u64 inum, struct btrfs_inode_ref *iref, + struct extent_buffer *eb, void *ctx) +{ + struct inode_fs_paths *ipath = ctx; + char *fspath; + char *fspath_min; + int i = ipath->fspath->elem_cnt; + const int s_ptr = sizeof(char *); + u32 bytes_left; + + bytes_left = ipath->fspath->bytes_left > s_ptr ? + ipath->fspath->bytes_left - s_ptr : 0; + + fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr; + fspath = iref_to_path(ipath->fs_root, ipath->btrfs_path, iref, eb, + inum, fspath_min, bytes_left); + if (IS_ERR(fspath)) + return PTR_ERR(fspath); + + if (fspath > fspath_min) { + ipath->fspath->val[i] = (u64)(unsigned long)fspath; + ++ipath->fspath->elem_cnt; + ipath->fspath->bytes_left = fspath - fspath_min; + } else { + ++ipath->fspath->elem_missed; + ipath->fspath->bytes_missing += fspath_min - fspath; + ipath->fspath->bytes_left = 0; + } + + return 0; +} + +/* + * this dumps all file system paths to the inode into the ipath struct, provided + * is has been created large enough. each path is zero-terminated and accessed + * from ipath->fspath->val[i]. + * when it returns, there are ipath->fspath->elem_cnt number of paths available + * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the + * number of missed paths in recored in ipath->fspath->elem_missed, otherwise, + * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would + * have been needed to return all paths. + */ +int paths_from_inode(u64 inum, struct inode_fs_paths *ipath) +{ + return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path, + inode_to_path, ipath); +} + +/* + * allocates space to return multiple file system paths for an inode. + * total_bytes to allocate are passed, note that space usable for actual path + * information will be total_bytes - sizeof(struct inode_fs_paths). + * the returned pointer must be freed with free_ipath() in the end. + */ +struct btrfs_data_container *init_data_container(u32 total_bytes) +{ + struct btrfs_data_container *data; + size_t alloc_bytes; + + alloc_bytes = max_t(size_t, total_bytes, sizeof(*data)); + data = kmalloc(alloc_bytes, GFP_NOFS); + if (!data) + return ERR_PTR(-ENOMEM); + + if (total_bytes >= sizeof(*data)) { + data->bytes_left = total_bytes - sizeof(*data); + data->bytes_missing = 0; + } else { + data->bytes_missing = sizeof(*data) - total_bytes; + data->bytes_left = 0; + } + + data->elem_cnt = 0; + data->elem_missed = 0; + + return data; +} + +/* + * allocates space to return multiple file system paths for an inode. + * total_bytes to allocate are passed, note that space usable for actual path + * information will be total_bytes - sizeof(struct inode_fs_paths). + * the returned pointer must be freed with free_ipath() in the end. + */ +struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, + struct btrfs_path *path) +{ + struct inode_fs_paths *ifp; + struct btrfs_data_container *fspath; + + fspath = init_data_container(total_bytes); + if (IS_ERR(fspath)) + return (void *)fspath; + + ifp = kmalloc(sizeof(*ifp), GFP_NOFS); + if (!ifp) { + kfree(fspath); + return ERR_PTR(-ENOMEM); + } + + ifp->btrfs_path = path; + ifp->fspath = fspath; + ifp->fs_root = fs_root; + + return ifp; +} + +void free_ipath(struct inode_fs_paths *ipath) +{ + kfree(ipath); +} diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h new file mode 100644 index 0000000..9261883 --- /dev/null +++ b/fs/btrfs/backref.h @@ -0,0 +1,62 @@ +/* + * Copyright (C) 2011 STRATO. 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. + */ + +#ifndef __BTRFS_BACKREF__ +#define __BTRFS_BACKREF__ + +#include "ioctl.h" + +struct inode_fs_paths { + struct btrfs_path *btrfs_path; + struct btrfs_root *fs_root; + struct btrfs_data_container *fspath; +}; + +typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root, + void *ctx); +typedef int (iterate_irefs_t)(u64 parent, struct btrfs_inode_ref *iref, + struct extent_buffer *eb, void *ctx); + +int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root, + struct btrfs_path *path); + +int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, + struct btrfs_path *path, struct btrfs_key *found_key); + +int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, + struct btrfs_extent_item *ei, u32 item_size, + u64 *out_root, u8 *out_level); + +int iterate_extent_inodes(struct btrfs_fs_info *fs_info, + struct btrfs_path *path, + u64 extent_item_objectid, + u64 extent_offset, + iterate_extent_inodes_t *iterate, void *ctx); + +int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, + struct btrfs_path *path, + iterate_extent_inodes_t *iterate, void *ctx); + +int paths_from_inode(u64 inum, struct inode_fs_paths *ipath); + +struct btrfs_data_container *init_data_container(u32 total_bytes); +struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, + struct btrfs_path *path); +void free_ipath(struct inode_fs_paths *ipath); + +#endif diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c new file mode 100644 index 0000000..2373b39 --- /dev/null +++ b/fs/btrfs/reada.c @@ -0,0 +1,951 @@ +/* + * Copyright (C) 2011 STRATO. 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/sched.h> +#include <linux/pagemap.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include <linux/rbtree.h> +#include <linux/slab.h> +#include <linux/workqueue.h> +#include "ctree.h" +#include "volumes.h" +#include "disk-io.h" +#include "transaction.h" + +#undef DEBUG + +/* + * This is the implementation for the generic read ahead framework. + * + * To trigger a readahead, btrfs_reada_add must be called. It will start + * a read ahead for the given range [start, end) on tree root. The returned + * handle can either be used to wait on the readahead to finish + * (btrfs_reada_wait), or to send it to the background (btrfs_reada_detach). + * + * The read ahead works as follows: + * On btrfs_reada_add, the root of the tree is inserted into a radix_tree. + * reada_start_machine will then search for extents to prefetch and trigger + * some reads. When a read finishes for a node, all contained node/leaf + * pointers that lie in the given range will also be enqueued. The reads will + * be triggered in sequential order, thus giving a big win over a naive + * enumeration. It will also make use of multi-device layouts. Each disk + * will have its on read pointer and all disks will by utilized in parallel. + * Also will no two disks read both sides of a mirror simultaneously, as this + * would waste seeking capacity. Instead both disks will read different parts + * of the filesystem. + * Any number of readaheads can be started in parallel. The read order will be + * determined globally, i.e. 2 parallel readaheads will normally finish faster + * than the 2 started one after another. + */ + +#define MAX_MIRRORS 2 +#define MAX_IN_FLIGHT 6 + +struct reada_extctl { + struct list_head list; + struct reada_control *rc; + u64 generation; +}; + +struct reada_extent { + u64 logical; + struct btrfs_key top; + u32 blocksize; + int err; + struct list_head extctl; + struct kref refcnt; + spinlock_t lock; + struct reada_zone *zones[MAX_MIRRORS]; + int nzones; + struct btrfs_device *scheduled_for; +}; + +struct reada_zone { + u64 start; + u64 end; + u64 elems; + struct list_head list; + spinlock_t lock; + int locked; + struct btrfs_device *device; + struct btrfs_device *devs[MAX_MIRRORS]; /* full list, incl self */ + int ndevs; + struct kref refcnt; +}; + +struct reada_machine_work { + struct btrfs_work work; + struct btrfs_fs_info *fs_info; +}; + +static void reada_extent_put(struct btrfs_fs_info *, struct reada_extent *); +static void reada_control_release(struct kref *kref); +static void reada_zone_release(struct kref *kref); +static void reada_start_machine(struct btrfs_fs_info *fs_info); +static void __reada_start_machine(struct btrfs_fs_info *fs_info); + +static int reada_add_block(struct reada_control *rc, u64 logical, + struct btrfs_key *top, int level, u64 generation); + +/* recurses */ +/* in case of err, eb might be NULL */ +static int __readahead_hook(struct btrfs_root *root, struct extent_buffer *eb, + u64 start, int err) +{ + int level = 0; + int nritems; + int i; + u64 bytenr; + u64 generation; + struct reada_extent *re; + struct btrfs_fs_info *fs_info = root->fs_info; + struct list_head list; + unsigned long index = start >> PAGE_CACHE_SHIFT; + struct btrfs_device *for_dev; + + if (eb) + level = btrfs_header_level(eb); + + /* find extent */ + spin_lock(&fs_info->reada_lock); + re = radix_tree_lookup(&fs_info->reada_tree, index); + if (re) + kref_get(&re->refcnt); + spin_unlock(&fs_info->reada_lock); + + if (!re) + return -1; + + spin_lock(&re->lock); + /* + * just take the full list from the extent. afterwards we + * don't need the lock anymore + */ + list_replace_init(&re->extctl, &list); + for_dev = re->scheduled_for; + re->scheduled_for = NULL; + spin_unlock(&re->lock); + + if (err == 0) { + nritems = level ? btrfs_header_nritems(eb) : 0; + generation = btrfs_header_generation(eb); + /* + * FIXME: currently we just set nritems to 0 if this is a leaf, + * effectively ignoring the content. In a next step we could + * trigger more readahead depending from the content, e.g. + * fetch the checksums for the extents in the leaf. + */ + } else { + /* + * this is the error case, the extent buffer has not been + * read correctly. We won't access anything from it and + * just cleanup our data structures. Effectively this will + * cut the branch below this node from read ahead. + */ + nritems = 0; + generation = 0; + } + + for (i = 0; i < nritems; i++) { + struct reada_extctl *rec; + u64 n_gen; + struct btrfs_key key; + struct btrfs_key next_key; + + btrfs_node_key_to_cpu(eb, &key, i); + if (i + 1 < nritems) + btrfs_node_key_to_cpu(eb, &next_key, i + 1); + else + next_key = re->top; + bytenr = btrfs_node_blockptr(eb, i); + n_gen = btrfs_node_ptr_generation(eb, i); + + list_for_each_entry(rec, &list, list) { + struct reada_control *rc = rec->rc; + + /* + * if the generation doesn't match, just ignore this + * extctl. This will probably cut off a branch from + * prefetch. Alternatively one could start a new (sub-) + * prefetch for this branch, starting again from root. + * FIXME: move the generation check out of this loop + */ +#ifdef DEBUG + if (rec->generation != generation) { + printk(KERN_DEBUG "generation mismatch for " + "(%llu,%d,%llu) %llu != %llu\n", + key.objectid, key.type, key.offset, + rec->generation, generation); + } +#endif + if (rec->generation == generation && + btrfs_comp_cpu_keys(&key, &rc->key_end) < 0 && + btrfs_comp_cpu_keys(&next_key, &rc->key_start) > 0) + reada_add_block(rc, bytenr, &next_key, + level - 1, n_gen); + } + } + /* + * free extctl records + */ + while (!list_empty(&list)) { + struct reada_control *rc; + struct reada_extctl *rec; + + rec = list_first_entry(&list, struct reada_extctl, list); + list_del(&rec->list); + rc = rec->rc; + kfree(rec); + + kref_get(&rc->refcnt); + if (atomic_dec_and_test(&rc->elems)) { + kref_put(&rc->refcnt, reada_control_release); + wake_up(&rc->wait); + } + kref_put(&rc->refcnt, reada_control_release); + + reada_extent_put(fs_info, re); /* one ref for each entry */ + } + reada_extent_put(fs_info, re); /* our ref */ + if (for_dev) + atomic_dec(&for_dev->reada_in_flight); + + return 0; +} + +/* + * start is passed separately in case eb in NULL, which may be the case with + * failed I/O + */ +int btree_readahead_hook(struct btrfs_root *root, struct extent_buffer *eb, + u64 start, int err) +{ + int ret; + + ret = __readahead_hook(root, eb, start, err); + + reada_start_machine(root->fs_info); + + return ret; +} + +static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info, + struct btrfs_device *dev, u64 logical, + struct btrfs_bio *bbio) +{ + int ret; + int looped = 0; + struct reada_zone *zone; + struct btrfs_block_group_cache *cache = NULL; + u64 start; + u64 end; + int i; + +again: + zone = NULL; + spin_lock(&fs_info->reada_lock); + ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone, + logical >> PAGE_CACHE_SHIFT, 1); + if (ret == 1) + kref_get(&zone->refcnt); + spin_unlock(&fs_info->reada_lock); + + if (ret == 1) { + if (logical >= zone->start && logical < zone->end) + return zone; + spin_lock(&fs_info->reada_lock); + kref_put(&zone->refcnt, reada_zone_release); + spin_unlock(&fs_info->reada_lock); + } + + if (looped) + return NULL; + + cache = btrfs_lookup_block_group(fs_info, logical); + if (!cache) + return NULL; + + start = cache->key.objectid; + end = start + cache->key.offset - 1; + btrfs_put_block_group(cache); + + zone = kzalloc(sizeof(*zone), GFP_NOFS); + if (!zone) + return NULL; + + zone->start = start; + zone->end = end; + INIT_LIST_HEAD(&zone->list); + spin_lock_init(&zone->lock); + zone->locked = 0; + kref_init(&zone->refcnt); + zone->elems = 0; + zone->device = dev; /* our device always sits at index 0 */ + for (i = 0; i < bbio->num_stripes; ++i) { + /* bounds have already been checked */ + zone->devs[i] = bbio->stripes[i].dev; + } + zone->ndevs = bbio->num_stripes; + + spin_lock(&fs_info->reada_lock); + ret = radix_tree_insert(&dev->reada_zones, + (unsigned long)zone->end >> PAGE_CACHE_SHIFT, + zone); + spin_unlock(&fs_info->reada_lock); + + if (ret) { + kfree(zone); + looped = 1; + goto again; + } + + return zone; +} + +static struct reada_extent *reada_find_extent(struct btrfs_root *root, + u64 logical, + struct btrfs_key *top, int level) +{ + int ret; + int looped = 0; + struct reada_extent *re = NULL; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; + struct btrfs_bio *bbio = NULL; + struct btrfs_device *dev; + u32 blocksize; + u64 length; + int nzones = 0; + int i; + unsigned long index = logical >> PAGE_CACHE_SHIFT; + +again: + spin_lock(&fs_info->reada_lock); + re = radix_tree_lookup(&fs_info->reada_tree, index); + if (re) + kref_get(&re->refcnt); + spin_unlock(&fs_info->reada_lock); + + if (re || looped) + return re; + + re = kzalloc(sizeof(*re), GFP_NOFS); + if (!re) + return NULL; + + blocksize = btrfs_level_size(root, level); + re->logical = logical; + re->blocksize = blocksize; + re->top = *top; + INIT_LIST_HEAD(&re->extctl); + spin_lock_init(&re->lock); + kref_init(&re->refcnt); + + /* + * map block + */ + length = blocksize; + ret = btrfs_map_block(map_tree, REQ_WRITE, logical, &length, &bbio, 0); + if (ret || !bbio || length < blocksize) + goto error; + + if (bbio->num_stripes > MAX_MIRRORS) { + printk(KERN_ERR "btrfs readahead: more than %d copies not " + "supported", MAX_MIRRORS); + goto error; + } + + for (nzones = 0; nzones < bbio->num_stripes; ++nzones) { + struct reada_zone *zone; + + dev = bbio->stripes[nzones].dev; + zone = reada_find_zone(fs_info, dev, logical, bbio); + if (!zone) + break; + + re->zones[nzones] = zone; + spin_lock(&zone->lock); + if (!zone->elems) + kref_get(&zone->refcnt); + ++zone->elems; + spin_unlock(&zone->lock); + spin_lock(&fs_info->reada_lock); + kref_put(&zone->refcnt, reada_zone_release); + spin_unlock(&fs_info->reada_lock); + } + re->nzones = nzones; + if (nzones == 0) { + /* not a single zone found, error and out */ + goto error; + } + + /* insert extent in reada_tree + all per-device trees, all or nothing */ + spin_lock(&fs_info->reada_lock); + ret = radix_tree_insert(&fs_info->reada_tree, index, re); + if (ret) { + spin_unlock(&fs_info->reada_lock); + if (ret != -ENOMEM) { + /* someone inserted the extent in the meantime */ + looped = 1; + } + goto error; + } + for (i = 0; i < nzones; ++i) { + dev = bbio->stripes[i].dev; + ret = radix_tree_insert(&dev->reada_extents, index, re); + if (ret) { + while (--i >= 0) { + dev = bbio->stripes[i].dev; + BUG_ON(dev == NULL); + radix_tree_delete(&dev->reada_extents, index); + } + BUG_ON(fs_info == NULL); + radix_tree_delete(&fs_info->reada_tree, index); + spin_unlock(&fs_info->reada_lock); + goto error; + } + } + spin_unlock(&fs_info->reada_lock); + + kfree(bbio); + return re; + +error: + while (nzones) { + struct reada_zone *zone; + + --nzones; + zone = re->zones[nzones]; + kref_get(&zone->refcnt); + spin_lock(&zone->lock); + --zone->elems; + if (zone->elems == 0) { + /* + * no fs_info->reada_lock needed, as this can't be + * the last ref + */ + kref_put(&zone->refcnt, reada_zone_release); + } + spin_unlock(&zone->lock); + + spin_lock(&fs_info->reada_lock); + kref_put(&zone->refcnt, reada_zone_release); + spin_unlock(&fs_info->reada_lock); + } + kfree(bbio); + kfree(re); + if (looped) + goto again; + return NULL; +} + +static void reada_kref_dummy(struct kref *kr) +{ +} + +static void reada_extent_put(struct btrfs_fs_info *fs_info, + struct reada_extent *re) +{ + int i; + unsigned long index = re->logical >> PAGE_CACHE_SHIFT; + + spin_lock(&fs_info->reada_lock); + if (!kref_put(&re->refcnt, reada_kref_dummy)) { + spin_unlock(&fs_info->reada_lock); + return; + } + + radix_tree_delete(&fs_info->reada_tree, index); + for (i = 0; i < re->nzones; ++i) { + struct reada_zone *zone = re->zones[i]; + + radix_tree_delete(&zone->device->reada_extents, index); + } + + spin_unlock(&fs_info->reada_lock); + + for (i = 0; i < re->nzones; ++i) { + struct reada_zone *zone = re->zones[i]; + + kref_get(&zone->refcnt); + spin_lock(&zone->lock); + --zone->elems; + if (zone->elems == 0) { + /* no fs_info->reada_lock needed, as this can't be + * the last ref */ + kref_put(&zone->refcnt, reada_zone_release); + } + spin_unlock(&zone->lock); + + spin_lock(&fs_info->reada_lock); + kref_put(&zone->refcnt, reada_zone_release); + spin_unlock(&fs_info->reada_lock); + } + if (re->scheduled_for) + atomic_dec(&re->scheduled_for->reada_in_flight); + + kfree(re); +} + +static void reada_zone_release(struct kref *kref) +{ + struct reada_zone *zone = container_of(kref, struct reada_zone, refcnt); + + radix_tree_delete(&zone->device->reada_zones, + zone->end >> PAGE_CACHE_SHIFT); + + kfree(zone); +} + +static void reada_control_release(struct kref *kref) +{ + struct reada_control *rc = container_of(kref, struct reada_control, + refcnt); + + kfree(rc); +} + +static int reada_add_block(struct reada_control *rc, u64 logical, + struct btrfs_key *top, int level, u64 generation) +{ + struct btrfs_root *root = rc->root; + struct reada_extent *re; + struct reada_extctl *rec; + + re = reada_find_extent(root, logical, top, level); /* takes one ref */ + if (!re) + return -1; + + rec = kzalloc(sizeof(*rec), GFP_NOFS); + if (!rec) { + reada_extent_put(root->fs_info, re); + return -1; + } + + rec->rc = rc; + rec->generation = generation; + atomic_inc(&rc->elems); + + spin_lock(&re->lock); + list_add_tail(&rec->list, &re->extctl); + spin_unlock(&re->lock); + + /* leave the ref on the extent */ + + return 0; +} + +/* + * called with fs_info->reada_lock held + */ +static void reada_peer_zones_set_lock(struct reada_zone *zone, int lock) +{ + int i; + unsigned long index = zone->end >> PAGE_CACHE_SHIFT; + + for (i = 0; i < zone->ndevs; ++i) { + struct reada_zone *peer; + peer = radix_tree_lookup(&zone->devs[i]->reada_zones, index); + if (peer && peer->device != zone->device) + peer->locked = lock; + } +} + +/* + * called with fs_info->reada_lock held + */ +static int reada_pick_zone(struct btrfs_device *dev) +{ + struct reada_zone *top_zone = NULL; + struct reada_zone *top_locked_zone = NULL; + u64 top_elems = 0; + u64 top_locked_elems = 0; + unsigned long index = 0; + int ret; + + if (dev->reada_curr_zone) { + reada_peer_zones_set_lock(dev->reada_curr_zone, 0); + kref_put(&dev->reada_curr_zone->refcnt, reada_zone_release); + dev->reada_curr_zone = NULL; + } + /* pick the zone with the most elements */ + while (1) { + struct reada_zone *zone; + + ret = radix_tree_gang_lookup(&dev->reada_zones, + (void **)&zone, index, 1); + if (ret == 0) + break; + index = (zone->end >> PAGE_CACHE_SHIFT) + 1; + if (zone->locked) { + if (zone->elems > top_locked_elems) { + top_locked_elems = zone->elems; + top_locked_zone = zone; + } + } else { + if (zone->elems > top_elems) { + top_elems = zone->elems; + top_zone = zone; + } + } + } + if (top_zone) + dev->reada_curr_zone = top_zone; + else if (top_locked_zone) + dev->reada_curr_zone = top_locked_zone; + else + return 0; + + dev->reada_next = dev->reada_curr_zone->start; + kref_get(&dev->reada_curr_zone->refcnt); + reada_peer_zones_set_lock(dev->reada_curr_zone, 1); + + return 1; +} + +static int reada_start_machine_dev(struct btrfs_fs_info *fs_info, + struct btrfs_device *dev) +{ + struct reada_extent *re = NULL; + int mirror_num = 0; + struct extent_buffer *eb = NULL; + u64 logical; + u32 blocksize; + int ret; + int i; + int need_kick = 0; + + spin_lock(&fs_info->reada_lock); + if (dev->reada_curr_zone == NULL) { + ret = reada_pick_zone(dev); + if (!ret) { + spin_unlock(&fs_info->reada_lock); + return 0; + } + } + /* + * FIXME currently we issue the reads one extent at a time. If we have + * a contiguous block of extents, we could also coagulate them or use + * plugging to speed things up + */ + ret = radix_tree_gang_lookup(&dev->reada_extents, (void **)&re, + dev->reada_next >> PAGE_CACHE_SHIFT, 1); + if (ret == 0 || re->logical >= dev->reada_curr_zone->end) { + ret = reada_pick_zone(dev); + if (!ret) { + spin_unlock(&fs_info->reada_lock); + return 0; + } + re = NULL; + ret = radix_tree_gang_lookup(&dev->reada_extents, (void **)&re, + dev->reada_next >> PAGE_CACHE_SHIFT, 1); + } + if (ret == 0) { + spin_unlock(&fs_info->reada_lock); + return 0; + } + dev->reada_next = re->logical + re->blocksize; + kref_get(&re->refcnt); + + spin_unlock(&fs_info->reada_lock); + + /* + * find mirror num + */ + for (i = 0; i < re->nzones; ++i) { + if (re->zones[i]->device == dev) { + mirror_num = i + 1; + break; + } + } + logical = re->logical; + blocksize = re->blocksize; + + spin_lock(&re->lock); + if (re->scheduled_for == NULL) { + re->scheduled_for = dev; + need_kick = 1; + } + spin_unlock(&re->lock); + + reada_extent_put(fs_info, re); + + if (!need_kick) + return 0; + + atomic_inc(&dev->reada_in_flight); + ret = reada_tree_block_flagged(fs_info->extent_root, logical, blocksize, + mirror_num, &eb); + if (ret) + __readahead_hook(fs_info->extent_root, NULL, logical, ret); + else if (eb) + __readahead_hook(fs_info->extent_root, eb, eb->start, ret); + + if (eb) + free_extent_buffer(eb); + + return 1; + +} + +static void reada_start_machine_worker(struct btrfs_work *work) +{ + struct reada_machine_work *rmw; + struct btrfs_fs_info *fs_info; + + rmw = container_of(work, struct reada_machine_work, work); + fs_info = rmw->fs_info; + + kfree(rmw); + + __reada_start_machine(fs_info); +} + +static void __reada_start_machine(struct btrfs_fs_info *fs_info) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + u64 enqueued; + u64 total = 0; + int i; + + do { + enqueued = 0; + list_for_each_entry(device, &fs_devices->devices, dev_list) { + if (atomic_read(&device->reada_in_flight) < + MAX_IN_FLIGHT) + enqueued += reada_start_machine_dev(fs_info, + device); + } + total += enqueued; + } while (enqueued && total < 10000); + + if (enqueued == 0) + return; + + /* + * If everything is already in the cache, this is effectively single + * threaded. To a) not hold the caller for too long and b) to utilize + * more cores, we broke the loop above after 10000 iterations and now + * enqueue to workers to finish it. This will distribute the load to + * the cores. + */ + for (i = 0; i < 2; ++i) + reada_start_machine(fs_info); +} + +static void reada_start_machine(struct btrfs_fs_info *fs_info) +{ + struct reada_machine_work *rmw; + + rmw = kzalloc(sizeof(*rmw), GFP_NOFS); + if (!rmw) { + /* FIXME we cannot handle this properly right now */ + BUG(); + } + rmw->work.func = reada_start_machine_worker; + rmw->fs_info = fs_info; + + btrfs_queue_worker(&fs_info->readahead_workers, &rmw->work); +} + +#ifdef DEBUG +static void dump_devs(struct btrfs_fs_info *fs_info, int all) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + unsigned long index; + int ret; + int i; + int j; + int cnt; + + spin_lock(&fs_info->reada_lock); + list_for_each_entry(device, &fs_devices->devices, dev_list) { + printk(KERN_DEBUG "dev %lld has %d in flight\n", device->devid, + atomic_read(&device->reada_in_flight)); + index = 0; + while (1) { + struct reada_zone *zone; + ret = radix_tree_gang_lookup(&device->reada_zones, + (void **)&zone, index, 1); + if (ret == 0) + break; + printk(KERN_DEBUG " zone %llu-%llu elems %llu locked " + "%d devs", zone->start, zone->end, zone->elems, + zone->locked); + for (j = 0; j < zone->ndevs; ++j) { + printk(KERN_CONT " %lld", + zone->devs[j]->devid); + } + if (device->reada_curr_zone == zone) + printk(KERN_CONT " curr off %llu", + device->reada_next - zone->start); + printk(KERN_CONT "\n"); + index = (zone->end >> PAGE_CACHE_SHIFT) + 1; + } + cnt = 0; + index = 0; + while (all) { + struct reada_extent *re = NULL; + + ret = radix_tree_gang_lookup(&device->reada_extents, + (void **)&re, index, 1); + if (ret == 0) + break; + printk(KERN_DEBUG + " re: logical %llu size %u empty %d for %lld", + re->logical, re->blocksize, + list_empty(&re->extctl), re->scheduled_for ? + re->scheduled_for->devid : -1); + + for (i = 0; i < re->nzones; ++i) { + printk(KERN_CONT " zone %llu-%llu devs", + re->zones[i]->start, + re->zones[i]->end); + for (j = 0; j < re->zones[i]->ndevs; ++j) { + printk(KERN_CONT " %lld", + re->zones[i]->devs[j]->devid); + } + } + printk(KERN_CONT "\n"); + index = (re->logical >> PAGE_CACHE_SHIFT) + 1; + if (++cnt > 15) + break; + } + } + + index = 0; + cnt = 0; + while (all) { + struct reada_extent *re = NULL; + + ret = radix_tree_gang_lookup(&fs_info->reada_tree, (void **)&re, + index, 1); + if (ret == 0) + break; + if (!re->scheduled_for) { + index = (re->logical >> PAGE_CACHE_SHIFT) + 1; + continue; + } + printk(KERN_DEBUG + "re: logical %llu size %u list empty %d for %lld", + re->logical, re->blocksize, list_empty(&re->extctl), + re->scheduled_for ? re->scheduled_for->devid : -1); + for (i = 0; i < re->nzones; ++i) { + printk(KERN_CONT " zone %llu-%llu devs", + re->zones[i]->start, + re->zones[i]->end); + for (i = 0; i < re->nzones; ++i) { + printk(KERN_CONT " zone %llu-%llu devs", + re->zones[i]->start, + re->zones[i]->end); + for (j = 0; j < re->zones[i]->ndevs; ++j) { + printk(KERN_CONT " %lld", + re->zones[i]->devs[j]->devid); + } + } + } + printk(KERN_CONT "\n"); + index = (re->logical >> PAGE_CACHE_SHIFT) + 1; + } + spin_unlock(&fs_info->reada_lock); +} +#endif + +/* + * interface + */ +struct reada_control *btrfs_reada_add(struct btrfs_root *root, + struct btrfs_key *key_start, struct btrfs_key *key_end) +{ + struct reada_control *rc; + u64 start; + u64 generation; + int level; + struct extent_buffer *node; + static struct btrfs_key max_key = { + .objectid = (u64)-1, + .type = (u8)-1, + .offset = (u64)-1 + }; + + rc = kzalloc(sizeof(*rc), GFP_NOFS); + if (!rc) + return ERR_PTR(-ENOMEM); + + rc->root = root; + rc->key_start = *key_start; + rc->key_end = *key_end; + atomic_set(&rc->elems, 0); + init_waitqueue_head(&rc->wait); + kref_init(&rc->refcnt); + kref_get(&rc->refcnt); /* one ref for having elements */ + + node = btrfs_root_node(root); + start = node->start; + level = btrfs_header_level(node); + generation = btrfs_header_generation(node); + free_extent_buffer(node); + + reada_add_block(rc, start, &max_key, level, generation); + + reada_start_machine(root->fs_info); + + return rc; +} + +#ifdef DEBUG +int btrfs_reada_wait(void *handle) +{ + struct reada_control *rc = handle; + + while (atomic_read(&rc->elems)) { + wait_event_timeout(rc->wait, atomic_read(&rc->elems) == 0, + 5 * HZ); + dump_devs(rc->root->fs_info, rc->elems < 10 ? 1 : 0); + } + + dump_devs(rc->root->fs_info, rc->elems < 10 ? 1 : 0); + + kref_put(&rc->refcnt, reada_control_release); + + return 0; +} +#else +int btrfs_reada_wait(void *handle) +{ + struct reada_control *rc = handle; + + while (atomic_read(&rc->elems)) { + wait_event(rc->wait, atomic_read(&rc->elems) == 0); + } + + kref_put(&rc->refcnt, reada_control_release); + + return 0; +} +#endif + +void btrfs_reada_detach(void *handle) +{ + struct reada_control *rc = handle; + + kref_put(&rc->refcnt, reada_control_release); +} |