// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) Qu Wenruo 2017.  All rights reserved.
 */

/*
 * The module is used to catch unexpected/corrupted tree block data.
 * Such behavior can be caused either by a fuzzed image or bugs.
 *
 * The objective is to do leaf/node validation checks when tree block is read
 * from disk, and check *every* possible member, so other code won't
 * need to checking them again.
 *
 * Due to the potential and unwanted damage, every checker needs to be
 * carefully reviewed otherwise so it does not prevent mount of valid images.
 */

#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/error-injection.h>
#include "messages.h"
#include "ctree.h"
#include "tree-checker.h"
#include "compression.h"
#include "volumes.h"
#include "misc.h"
#include "fs.h"
#include "accessors.h"
#include "file-item.h"
#include "inode-item.h"
#include "dir-item.h"
#include "extent-tree.h"

/*
 * Error message should follow the following format:
 * corrupt <type>: <identifier>, <reason>[, <bad_value>]
 *
 * @type:       leaf or node
 * @identifier: the necessary info to locate the leaf/node.
 *              It's recommended to decode key.objecitd/offset if it's
 *              meaningful.
 * @reason:     describe the error
 * @bad_value:  optional, it's recommended to output bad value and its
 *              expected value (range).
 *
 * Since comma is used to separate the components, only space is allowed
 * inside each component.
 */

/*
 * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
 * Allows callers to customize the output.
 */
__printf(3, 4)
__cold
static void generic_err(const struct extent_buffer *eb, int slot,
                        const char *fmt, ...)
{
        const struct btrfs_fs_info *fs_info = eb->fs_info;
        struct va_format vaf;
        va_list args;

        va_start(args, fmt);

        vaf.fmt = fmt;
        vaf.va = &args;

        dump_page(folio_page(eb->folios[0], 0), "eb page dump");
        btrfs_crit(fs_info,
                "corrupt %s: root=%llu block=%llu slot=%d, %pV",
                btrfs_header_level(eb) == 0 ? "leaf" : "node",
                btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, &vaf);
        va_end(args);
}

/*
 * Customized reporter for extent data item, since its key objectid and
 * offset has its own meaning.
 */
__printf(3, 4)
__cold
static void file_extent_err(const struct extent_buffer *eb, int slot,
                            const char *fmt, ...)
{
        const struct btrfs_fs_info *fs_info = eb->fs_info;
        struct btrfs_key key;
        struct va_format vaf;
        va_list args;

        btrfs_item_key_to_cpu(eb, &key, slot);
        va_start(args, fmt);

        vaf.fmt = fmt;
        vaf.va = &args;

        dump_page(folio_page(eb->folios[0], 0), "eb page dump");
        btrfs_crit(fs_info,
        "corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV",
                btrfs_header_level(eb) == 0 ? "leaf" : "node",
                btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
                key.objectid, key.offset, &vaf);
        va_end(args);
}

/*
 * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
 * Else return 1
 */
#define CHECK_FE_ALIGNED(leaf, slot, fi, name, alignment)                     \
({                                                                            \
        if (unlikely(!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)),      \
                                 (alignment))))                               \
                file_extent_err((leaf), (slot),                               \
        "invalid %s for file extent, have %llu, should be aligned to %u",     \
                        (#name), btrfs_file_extent_##name((leaf), (fi)),      \
                        (alignment));                                         \
        (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment)));   \
})

static u64 file_extent_end(struct extent_buffer *leaf,
                           struct btrfs_key *key,
                           struct btrfs_file_extent_item *extent)
{
        u64 end;
        u64 len;

        if (btrfs_file_extent_type(leaf, extent) == BTRFS_FILE_EXTENT_INLINE) {
                len = btrfs_file_extent_ram_bytes(leaf, extent);
                end = ALIGN(key->offset + len, leaf->fs_info->sectorsize);
        } else {
                len = btrfs_file_extent_num_bytes(leaf, extent);
                end = key->offset + len;
        }
        return end;
}

/*
 * Customized report for dir_item, the only new important information is
 * key->objectid, which represents inode number
 */
__printf(3, 4)
__cold
static void dir_item_err(const struct extent_buffer *eb, int slot,
                         const char *fmt, ...)
{
        const struct btrfs_fs_info *fs_info = eb->fs_info;
        struct btrfs_key key;
        struct va_format vaf;
        va_list args;

        btrfs_item_key_to_cpu(eb, &key, slot);
        va_start(args, fmt);

        vaf.fmt = fmt;
        vaf.va = &args;

        dump_page(folio_page(eb->folios[0], 0), "eb page dump");
        btrfs_crit(fs_info,
                "corrupt %s: root=%llu block=%llu slot=%d ino=%llu, %pV",
                btrfs_header_level(eb) == 0 ? "leaf" : "node",
                btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
                key.objectid, &vaf);
        va_end(args);
}

/*
 * This functions checks prev_key->objectid, to ensure current key and prev_key
 * share the same objectid as inode number.
 *
 * This is to detect missing INODE_ITEM in subvolume trees.
 *
 * Return true if everything is OK or we don't need to check.
 * Return false if anything is wrong.
 */
static bool check_prev_ino(struct extent_buffer *leaf,
                           struct btrfs_key *key, int slot,
                           struct btrfs_key *prev_key)
{
        /* No prev key, skip check */
        if (slot == 0)
                return true;

        /* Only these key->types needs to be checked */
        ASSERT(key->type == BTRFS_XATTR_ITEM_KEY ||
               key->type == BTRFS_INODE_REF_KEY ||
               key->type == BTRFS_INODE_EXTREF_KEY ||
               key->type == BTRFS_DIR_INDEX_KEY ||
               key->type == BTRFS_DIR_ITEM_KEY ||
               key->type == BTRFS_EXTENT_DATA_KEY, "key->type=%u", key->type);

        /*
         * Only subvolume trees along with their reloc trees need this check.
         * Things like log tree doesn't follow this ino requirement.
         */
        if (!btrfs_is_fstree(btrfs_header_owner(leaf)))
                return true;

        if (key->objectid == prev_key->objectid)
                return true;

        /* Error found */
        dir_item_err(leaf, slot,
                "invalid previous key objectid, have %llu expect %llu",
                prev_key->objectid, key->objectid);
        return false;
}
static int check_extent_data_item(struct extent_buffer *leaf,
                                  struct btrfs_key *key, int slot,
                                  struct btrfs_key *prev_key)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        struct btrfs_file_extent_item *fi;
        u32 sectorsize = fs_info->sectorsize;
        u32 item_size = btrfs_item_size(leaf, slot);
        u64 extent_end;

        if (unlikely(!IS_ALIGNED(key->offset, sectorsize))) {
                file_extent_err(leaf, slot,
"unaligned file_offset for file extent, have %llu should be aligned to %u",
                        key->offset, sectorsize);
                return -EUCLEAN;
        }

        /*
         * Previous key must have the same key->objectid (ino).
         * It can be XATTR_ITEM, INODE_ITEM or just another EXTENT_DATA.
         * But if objectids mismatch, it means we have a missing
         * INODE_ITEM.
         */
        if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
                return -EUCLEAN;

        fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);

        /*
         * Make sure the item contains at least inline header, so the file
         * extent type is not some garbage.
         */
        if (unlikely(item_size < BTRFS_FILE_EXTENT_INLINE_DATA_START)) {
                file_extent_err(leaf, slot,
                                "invalid item size, have %u expect [%zu, %u)",
                                item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START,
                                SZ_4K);
                return -EUCLEAN;
        }
        if (unlikely(btrfs_file_extent_type(leaf, fi) >=
                     BTRFS_NR_FILE_EXTENT_TYPES)) {
                file_extent_err(leaf, slot,
                "invalid type for file extent, have %u expect range [0, %u]",
                        btrfs_file_extent_type(leaf, fi),
                        BTRFS_NR_FILE_EXTENT_TYPES - 1);
                return -EUCLEAN;
        }

        /*
         * Support for new compression/encryption must introduce incompat flag,
         * and must be caught in open_ctree().
         */
        if (unlikely(btrfs_file_extent_compression(leaf, fi) >=
                     BTRFS_NR_COMPRESS_TYPES)) {
                file_extent_err(leaf, slot,
        "invalid compression for file extent, have %u expect range [0, %u]",
                        btrfs_file_extent_compression(leaf, fi),
                        BTRFS_NR_COMPRESS_TYPES - 1);
                return -EUCLEAN;
        }
        if (unlikely(btrfs_file_extent_encryption(leaf, fi))) {
                file_extent_err(leaf, slot,
                        "invalid encryption for file extent, have %u expect 0",
                        btrfs_file_extent_encryption(leaf, fi));
                return -EUCLEAN;
        }
        if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
                /* Inline extent must have 0 as key offset */
                if (unlikely(key->offset)) {
                        file_extent_err(leaf, slot,
                "invalid file_offset for inline file extent, have %llu expect 0",
                                key->offset);
                        return -EUCLEAN;
                }

                /* Compressed inline extent has no on-disk size, skip it */
                if (btrfs_file_extent_compression(leaf, fi) !=
                    BTRFS_COMPRESS_NONE)
                        return 0;

                /* Uncompressed inline extent size must match item size */
                if (unlikely(item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
                                          btrfs_file_extent_ram_bytes(leaf, fi))) {
                        file_extent_err(leaf, slot,
        "invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
                                item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
                                btrfs_file_extent_ram_bytes(leaf, fi));
                        return -EUCLEAN;
                }
                return 0;
        }

        /* Regular or preallocated extent has fixed item size */
        if (unlikely(item_size != sizeof(*fi))) {
                file_extent_err(leaf, slot,
        "invalid item size for reg/prealloc file extent, have %u expect %zu",
                        item_size, sizeof(*fi));
                return -EUCLEAN;
        }
        if (unlikely(CHECK_FE_ALIGNED(leaf, slot, fi, ram_bytes, sectorsize) ||
                     CHECK_FE_ALIGNED(leaf, slot, fi, disk_bytenr, sectorsize) ||
                     CHECK_FE_ALIGNED(leaf, slot, fi, disk_num_bytes, sectorsize) ||
                     CHECK_FE_ALIGNED(leaf, slot, fi, offset, sectorsize) ||
                     CHECK_FE_ALIGNED(leaf, slot, fi, num_bytes, sectorsize)))
                return -EUCLEAN;

        /* Catch extent end overflow */
        if (unlikely(check_add_overflow(btrfs_file_extent_num_bytes(leaf, fi),
                                        key->offset, &extent_end))) {
                file_extent_err(leaf, slot,
        "extent end overflow, have file offset %llu extent num bytes %llu",
                                key->offset,
                                btrfs_file_extent_num_bytes(leaf, fi));
                return -EUCLEAN;
        }

        /*
         * Check that no two consecutive file extent items, in the same leaf,
         * present ranges that overlap each other.
         */
        if (slot > 0 &&
            prev_key->objectid == key->objectid &&
            prev_key->type == BTRFS_EXTENT_DATA_KEY) {
                struct btrfs_file_extent_item *prev_fi;
                u64 prev_end;

                prev_fi = btrfs_item_ptr(leaf, slot - 1,
                                         struct btrfs_file_extent_item);
                prev_end = file_extent_end(leaf, prev_key, prev_fi);
                if (unlikely(prev_end > key->offset)) {
                        file_extent_err(leaf, slot - 1,
"file extent end range (%llu) goes beyond start offset (%llu) of the next file extent",
                                        prev_end, key->offset);
                        return -EUCLEAN;
                }
        }

        /*
         * For non-compressed data extents, ram_bytes should match its
         * disk_num_bytes.
         * However we do not really utilize ram_bytes in this case, so this check
         * is only optional for DEBUG builds for developers to catch the
         * unexpected behaviors.
         */
        if (IS_ENABLED(CONFIG_BTRFS_DEBUG) &&
            btrfs_file_extent_compression(leaf, fi) == BTRFS_COMPRESS_NONE &&
            btrfs_file_extent_disk_bytenr(leaf, fi)) {
                if (WARN_ON(btrfs_file_extent_ram_bytes(leaf, fi) !=
                            btrfs_file_extent_disk_num_bytes(leaf, fi)))
                        file_extent_err(leaf, slot,
"mismatch ram_bytes (%llu) and disk_num_bytes (%llu) for non-compressed extent",
                                        btrfs_file_extent_ram_bytes(leaf, fi),
                                        btrfs_file_extent_disk_num_bytes(leaf, fi));
        }

        return 0;
}

static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
                           int slot, struct btrfs_key *prev_key)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        u32 sectorsize = fs_info->sectorsize;
        const u32 csumsize = fs_info->csum_size;

        if (unlikely(key->objectid != BTRFS_EXTENT_CSUM_OBJECTID)) {
                generic_err(leaf, slot,
                "invalid key objectid for csum item, have %llu expect %llu",
                        key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
                return -EUCLEAN;
        }
        if (unlikely(!IS_ALIGNED(key->offset, sectorsize))) {
                generic_err(leaf, slot,
        "unaligned key offset for csum item, have %llu should be aligned to %u",
                        key->offset, sectorsize);
                return -EUCLEAN;
        }
        if (unlikely(!IS_ALIGNED(btrfs_item_size(leaf, slot), csumsize))) {
                generic_err(leaf, slot,
        "unaligned item size for csum item, have %u should be aligned to %u",
                        btrfs_item_size(leaf, slot), csumsize);
                return -EUCLEAN;
        }
        if (slot > 0 && prev_key->type == BTRFS_EXTENT_CSUM_KEY) {
                u64 prev_csum_end;
                u32 prev_item_size;

                prev_item_size = btrfs_item_size(leaf, slot - 1);
                prev_csum_end = (prev_item_size / csumsize) * sectorsize;
                prev_csum_end += prev_key->offset;
                if (unlikely(prev_csum_end > key->offset)) {
                        generic_err(leaf, slot - 1,
"csum end range (%llu) goes beyond the start range (%llu) of the next csum item",
                                    prev_csum_end, key->offset);
                        return -EUCLEAN;
                }
        }
        return 0;
}

/* Inode item error output has the same format as dir_item_err() */
#define inode_item_err(eb, slot, fmt, ...)                      \
        dir_item_err(eb, slot, fmt, __VA_ARGS__)

static int check_inode_key(struct extent_buffer *leaf, struct btrfs_key *key,
                           int slot)
{
        struct btrfs_key item_key;
        bool is_inode_item;

        btrfs_item_key_to_cpu(leaf, &item_key, slot);
        is_inode_item = (item_key.type == BTRFS_INODE_ITEM_KEY);

        /* For XATTR_ITEM, location key should be all 0 */
        if (item_key.type == BTRFS_XATTR_ITEM_KEY) {
                if (unlikely(key->objectid != 0 || key->type != 0 ||
                             key->offset != 0))
                        return -EUCLEAN;
                return 0;
        }

        if (unlikely((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
                      key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
                     key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
                     key->objectid != BTRFS_FREE_INO_OBJECTID)) {
                if (is_inode_item) {
                        generic_err(leaf, slot,
        "invalid key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
                                key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
                                BTRFS_FIRST_FREE_OBJECTID,
                                BTRFS_LAST_FREE_OBJECTID,
                                BTRFS_FREE_INO_OBJECTID);
                } else {
                        dir_item_err(leaf, slot,
"invalid location key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
                                key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
                                BTRFS_FIRST_FREE_OBJECTID,
                                BTRFS_LAST_FREE_OBJECTID,
                                BTRFS_FREE_INO_OBJECTID);
                }
                return -EUCLEAN;
        }
        if (unlikely(key->offset != 0)) {
                if (is_inode_item)
                        inode_item_err(leaf, slot,
                                       "invalid key offset: has %llu expect 0",
                                       key->offset);
                else
                        dir_item_err(leaf, slot,
                                "invalid location key offset:has %llu expect 0",
                                key->offset);
                return -EUCLEAN;
        }
        return 0;
}

static int check_root_key(struct extent_buffer *leaf, struct btrfs_key *key,
                          int slot)
{
        struct btrfs_key item_key;
        bool is_root_item;

        btrfs_item_key_to_cpu(leaf, &item_key, slot);
        is_root_item = (item_key.type == BTRFS_ROOT_ITEM_KEY);

        /*
         * Bad rootid for reloc trees.
         *
         * Reloc trees are only for subvolume trees, other trees only need
         * to be COWed to be relocated.
         */
        if (unlikely(is_root_item && key->objectid == BTRFS_TREE_RELOC_OBJECTID &&
                     !btrfs_is_fstree(key->offset))) {
                generic_err(leaf, slot,
                "invalid reloc tree for root %lld, root id is not a subvolume tree",
                            key->offset);
                return -EUCLEAN;
        }

        /* No such tree id */
        if (unlikely(key->objectid == 0)) {
                if (is_root_item)
                        generic_err(leaf, slot, "invalid root id 0");
                else
                        dir_item_err(leaf, slot,
                                     "invalid location key root id 0");
                return -EUCLEAN;
        }

        /* DIR_ITEM/INDEX/INODE_REF is not allowed to point to non-fs trees */
        if (unlikely(!btrfs_is_fstree(key->objectid) && !is_root_item)) {
                dir_item_err(leaf, slot,
                "invalid location key objectid, have %llu expect [%llu, %llu]",
                                key->objectid, BTRFS_FIRST_FREE_OBJECTID,
                                BTRFS_LAST_FREE_OBJECTID);
                return -EUCLEAN;
        }

        /*
         * ROOT_ITEM with non-zero offset means this is a snapshot, created at
         * @offset transid.
         * Furthermore, for location key in DIR_ITEM, its offset is always -1.
         *
         * So here we only check offset for reloc tree whose key->offset must
         * be a valid tree.
         */
        if (unlikely(key->objectid == BTRFS_TREE_RELOC_OBJECTID &&
                     key->offset == 0)) {
                generic_err(leaf, slot, "invalid root id 0 for reloc tree");
                return -EUCLEAN;
        }
        return 0;
}

static int check_dir_item(struct extent_buffer *leaf,
                          struct btrfs_key *key, struct btrfs_key *prev_key,
                          int slot)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        struct btrfs_dir_item *di;
        u32 item_size = btrfs_item_size(leaf, slot);
        u32 cur = 0;

        if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
                return -EUCLEAN;

        di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
        while (cur < item_size) {
                struct btrfs_key location_key;
                u32 name_len;
                u32 data_len;
                u32 max_name_len;
                u32 total_size;
                u32 name_hash;
                u8 dir_type;
                int ret;

                /* header itself should not cross item boundary */
                if (unlikely(cur + sizeof(*di) > item_size)) {
                        dir_item_err(leaf, slot,
                "dir item header crosses item boundary, have %zu boundary %u",
                                cur + sizeof(*di), item_size);
                        return -EUCLEAN;
                }

                /* Location key check */
                btrfs_dir_item_key_to_cpu(leaf, di, &location_key);
                if (location_key.type == BTRFS_ROOT_ITEM_KEY) {
                        ret = check_root_key(leaf, &location_key, slot);
                        if (unlikely(ret < 0))
                                return ret;
                } else if (location_key.type == BTRFS_INODE_ITEM_KEY ||
                           location_key.type == 0) {
                        ret = check_inode_key(leaf, &location_key, slot);
                        if (unlikely(ret < 0))
                                return ret;
                } else {
                        dir_item_err(leaf, slot,
                        "invalid location key type, have %u, expect %u or %u",
                                     location_key.type, BTRFS_ROOT_ITEM_KEY,
                                     BTRFS_INODE_ITEM_KEY);
                        return -EUCLEAN;
                }

                /* dir type check */
                dir_type = btrfs_dir_ftype(leaf, di);
                if (unlikely(dir_type <= BTRFS_FT_UNKNOWN ||
                             dir_type >= BTRFS_FT_MAX)) {
                        dir_item_err(leaf, slot,
                        "invalid dir item type, have %u expect (0, %u)",
                                dir_type, BTRFS_FT_MAX);
                        return -EUCLEAN;
                }

                if (unlikely(key->type == BTRFS_XATTR_ITEM_KEY &&
                             dir_type != BTRFS_FT_XATTR)) {
                        dir_item_err(leaf, slot,
                "invalid dir item type for XATTR key, have %u expect %u",
                                dir_type, BTRFS_FT_XATTR);
                        return -EUCLEAN;
                }
                if (unlikely(dir_type == BTRFS_FT_XATTR &&
                             key->type != BTRFS_XATTR_ITEM_KEY)) {
                        dir_item_err(leaf, slot,
                        "xattr dir type found for non-XATTR key");
                        return -EUCLEAN;
                }
                if (dir_type == BTRFS_FT_XATTR)
                        max_name_len = XATTR_NAME_MAX;
                else
                        max_name_len = BTRFS_NAME_LEN;

                /* Name/data length check */
                name_len = btrfs_dir_name_len(leaf, di);
                data_len = btrfs_dir_data_len(leaf, di);
                if (unlikely(name_len > max_name_len)) {
                        dir_item_err(leaf, slot,
                        "dir item name len too long, have %u max %u",
                                name_len, max_name_len);
                        return -EUCLEAN;
                }
                if (unlikely(name_len + data_len > BTRFS_MAX_XATTR_SIZE(fs_info))) {
                        dir_item_err(leaf, slot,
                        "dir item name and data len too long, have %u max %u",
                                name_len + data_len,
                                BTRFS_MAX_XATTR_SIZE(fs_info));
                        return -EUCLEAN;
                }

                if (unlikely(data_len && dir_type != BTRFS_FT_XATTR)) {
                        dir_item_err(leaf, slot,
                        "dir item with invalid data len, have %u expect 0",
                                data_len);
                        return -EUCLEAN;
                }

                total_size = sizeof(*di) + name_len + data_len;

                /* header and name/data should not cross item boundary */
                if (unlikely(cur + total_size > item_size)) {
                        dir_item_err(leaf, slot,
                "dir item data crosses item boundary, have %u boundary %u",
                                cur + total_size, item_size);
                        return -EUCLEAN;
                }

                /*
                 * Special check for XATTR/DIR_ITEM, as key->offset is name
                 * hash, should match its name
                 */
                if (key->type == BTRFS_DIR_ITEM_KEY ||
                    key->type == BTRFS_XATTR_ITEM_KEY) {
                        char namebuf[MAX(BTRFS_NAME_LEN, XATTR_NAME_MAX)];

                        read_extent_buffer(leaf, namebuf,
                                        (unsigned long)(di + 1), name_len);
                        name_hash = btrfs_name_hash(namebuf, name_len);
                        if (unlikely(key->offset != name_hash)) {
                                dir_item_err(leaf, slot,
                "name hash mismatch with key, have 0x%016x expect 0x%016llx",
                                        name_hash, key->offset);
                                return -EUCLEAN;
                        }
                }
                cur += total_size;
                di = (struct btrfs_dir_item *)((void *)di + total_size);
        }
        return 0;
}

__printf(3, 4)
__cold
static void block_group_err(const struct extent_buffer *eb, int slot,
                            const char *fmt, ...)
{
        const struct btrfs_fs_info *fs_info = eb->fs_info;
        struct btrfs_key key;
        struct va_format vaf;
        va_list args;

        btrfs_item_key_to_cpu(eb, &key, slot);
        va_start(args, fmt);

        vaf.fmt = fmt;
        vaf.va = &args;

        dump_page(folio_page(eb->folios[0], 0), "eb page dump");
        btrfs_crit(fs_info,
        "corrupt %s: root=%llu block=%llu slot=%d bg_start=%llu bg_len=%llu, %pV",
                btrfs_header_level(eb) == 0 ? "leaf" : "node",
                btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
                key.objectid, key.offset, &vaf);
        va_end(args);
}

static int check_block_group_item(struct extent_buffer *leaf,
                                  struct btrfs_key *key, int slot)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        struct btrfs_block_group_item bgi;
        u32 item_size = btrfs_item_size(leaf, slot);
        u64 chunk_objectid;
        u64 flags;
        u64 type;
        size_t exp_size;

        /*
         * Here we don't really care about alignment since extent allocator can
         * handle it.  We care more about the size.
         */
        if (unlikely(key->offset == 0)) {
                block_group_err(leaf, slot,
                                "invalid block group size 0");
                return -EUCLEAN;
        }

        if (btrfs_fs_incompat(fs_info, REMAP_TREE))
                exp_size = sizeof(struct btrfs_block_group_item_v2);
        else
                exp_size = sizeof(struct btrfs_block_group_item);

        if (unlikely(item_size != exp_size)) {
                block_group_err(leaf, slot,
                        "invalid item size, have %u expect %zu",
                                item_size, exp_size);
                return -EUCLEAN;
        }

        read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
                           sizeof(bgi));
        chunk_objectid = btrfs_stack_block_group_chunk_objectid(&bgi);
        if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
                /*
                 * We don't init the nr_global_roots until we load the global
                 * roots, so this could be 0 at mount time.  If it's 0 we'll
                 * just assume we're fine, and later we'll check against our
                 * actual value.
                 */
                if (unlikely(fs_info->nr_global_roots &&
                             chunk_objectid >= fs_info->nr_global_roots)) {
                        block_group_err(leaf, slot,
        "invalid block group global root id, have %llu, needs to be <= %llu",
                                        chunk_objectid,
                                        fs_info->nr_global_roots);
                        return -EUCLEAN;
                }
        } else if (unlikely(chunk_objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID)) {
                block_group_err(leaf, slot,
                "invalid block group chunk objectid, have %llu expect %llu",
                                btrfs_stack_block_group_chunk_objectid(&bgi),
                                BTRFS_FIRST_CHUNK_TREE_OBJECTID);
                return -EUCLEAN;
        }

        if (unlikely(btrfs_stack_block_group_used(&bgi) > key->offset)) {
                block_group_err(leaf, slot,
                        "invalid block group used, have %llu expect [0, %llu)",
                                btrfs_stack_block_group_used(&bgi), key->offset);
                return -EUCLEAN;
        }

        flags = btrfs_stack_block_group_flags(&bgi);
        if (unlikely(hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1)) {
                block_group_err(leaf, slot,
"invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set",
                        flags & BTRFS_BLOCK_GROUP_PROFILE_MASK,
                        hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK));
                return -EUCLEAN;
        }

        if (unlikely(flags & BTRFS_BLOCK_GROUP_METADATA_REMAP &&
                     !btrfs_fs_incompat(fs_info, REMAP_TREE))) {
                block_group_err(leaf, slot,
"invalid flags, have 0x%llx (METADATA_REMAP flag set) but no remap-tree incompat flag",
                                flags);
                return -EUCLEAN;
        }

        type = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
        if (unlikely(type != BTRFS_BLOCK_GROUP_DATA &&
                     type != BTRFS_BLOCK_GROUP_METADATA &&
                     type != BTRFS_BLOCK_GROUP_SYSTEM &&
                     type != BTRFS_BLOCK_GROUP_METADATA_REMAP &&
                     type != (BTRFS_BLOCK_GROUP_METADATA |
                              BTRFS_BLOCK_GROUP_DATA))) {
                block_group_err(leaf, slot,
"invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llx, 0x%llx or 0x%llx",
                        type, hweight64(type),
                        BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA,
                        BTRFS_BLOCK_GROUP_SYSTEM, BTRFS_BLOCK_GROUP_METADATA_REMAP,
                        BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA);
                return -EUCLEAN;
        }
        return 0;
}

__printf(5, 6)
__cold
static void chunk_err(const struct btrfs_fs_info *fs_info,
                      const struct extent_buffer *leaf,
                      const struct btrfs_chunk *chunk, u64 logical,
                      const char *fmt, ...)
{
        bool is_sb = !leaf;
        struct va_format vaf;
        va_list args;
        int i;
        int slot = -1;

        if (!is_sb) {
                /*
                 * Get the slot number by iterating through all slots, this
                 * would provide better readability.
                 */
                for (i = 0; i < btrfs_header_nritems(leaf); i++) {
                        if (btrfs_item_ptr_offset(leaf, i) ==
                                        (unsigned long)chunk) {
                                slot = i;
                                break;
                        }
                }
        }
        va_start(args, fmt);
        vaf.fmt = fmt;
        vaf.va = &args;

        if (is_sb)
                btrfs_crit(fs_info,
                "corrupt superblock syschunk array: chunk_start=%llu, %pV",
                           logical, &vaf);
        else
                btrfs_crit(fs_info,
        "corrupt leaf: root=%llu block=%llu slot=%d chunk_start=%llu, %pV",
                           BTRFS_CHUNK_TREE_OBJECTID, leaf->start, slot,
                           logical, &vaf);
        va_end(args);
}

static bool valid_stripe_count(u64 profile, u16 num_stripes, u16 sub_stripes)
{
        switch (profile) {
        case BTRFS_BLOCK_GROUP_RAID0:
                return true;
        case BTRFS_BLOCK_GROUP_RAID10:
                return sub_stripes == btrfs_raid_array[BTRFS_RAID_RAID10].sub_stripes;
        case BTRFS_BLOCK_GROUP_RAID1:
                return num_stripes == btrfs_raid_array[BTRFS_RAID_RAID1].devs_min;
        case BTRFS_BLOCK_GROUP_RAID1C3:
                return num_stripes == btrfs_raid_array[BTRFS_RAID_RAID1C3].devs_min;
        case BTRFS_BLOCK_GROUP_RAID1C4:
                return num_stripes == btrfs_raid_array[BTRFS_RAID_RAID1C4].devs_min;
        case BTRFS_BLOCK_GROUP_RAID5:
                return num_stripes >= btrfs_raid_array[BTRFS_RAID_RAID5].devs_min;
        case BTRFS_BLOCK_GROUP_RAID6:
                return num_stripes >= btrfs_raid_array[BTRFS_RAID_RAID6].devs_min;
        case BTRFS_BLOCK_GROUP_DUP:
                return num_stripes == btrfs_raid_array[BTRFS_RAID_DUP].dev_stripes;
        case 0: /* SINGLE */
                return num_stripes == btrfs_raid_array[BTRFS_RAID_SINGLE].dev_stripes;
        default:
                BUG();
        }
}

/*
 * The common chunk check which could also work on super block sys chunk array.
 *
 * If @leaf is NULL, then @chunk must be an on-stack chunk item.
 * (For superblock sys_chunk array, and fs_info->sectorsize is unreliable)
 *
 * Return -EUCLEAN if anything is corrupted.
 * Return 0 if everything is OK.
 */
int btrfs_check_chunk_valid(const struct btrfs_fs_info *fs_info,
                            const struct extent_buffer *leaf,
                            const struct btrfs_chunk *chunk, u64 logical,
                            u32 sectorsize)
{
        u64 length;
        u64 chunk_end;
        u64 stripe_len;
        u16 num_stripes;
        u16 sub_stripes;
        u64 type;
        u64 features;
        u32 chunk_sector_size;
        bool mixed = false;
        bool remapped;
        int raid_index;
        int nparity;
        int ncopies;

        if (leaf) {
                length = btrfs_chunk_length(leaf, chunk);
                stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
                num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
                sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
                type = btrfs_chunk_type(leaf, chunk);
                chunk_sector_size = btrfs_chunk_sector_size(leaf, chunk);
        } else {
                length = btrfs_stack_chunk_length(chunk);
                stripe_len = btrfs_stack_chunk_stripe_len(chunk);
                num_stripes = btrfs_stack_chunk_num_stripes(chunk);
                sub_stripes = btrfs_stack_chunk_sub_stripes(chunk);
                type = btrfs_stack_chunk_type(chunk);
                chunk_sector_size = btrfs_stack_chunk_sector_size(chunk);
        }
        raid_index = btrfs_bg_flags_to_raid_index(type);
        ncopies = btrfs_raid_array[raid_index].ncopies;
        nparity = btrfs_raid_array[raid_index].nparity;
        remapped = (type & BTRFS_BLOCK_GROUP_REMAPPED);

        if (unlikely(!remapped && !num_stripes)) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "invalid chunk num_stripes, have %u", num_stripes);
                return -EUCLEAN;
        }
        if (unlikely(num_stripes != 0 && num_stripes < ncopies)) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "invalid chunk num_stripes < ncopies, have %u < %d",
                          num_stripes, ncopies);
                return -EUCLEAN;
        }
        if (unlikely(nparity && num_stripes == nparity)) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "invalid chunk num_stripes == nparity, have %u == %d",
                          num_stripes, nparity);
                return -EUCLEAN;
        }
        if (unlikely(!IS_ALIGNED(logical, sectorsize))) {
                chunk_err(fs_info, leaf, chunk, logical,
                "invalid chunk logical, have %llu should aligned to %u",
                          logical, sectorsize);
                return -EUCLEAN;
        }
        if (unlikely(chunk_sector_size != sectorsize)) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "invalid chunk sectorsize, have %u expect %u",
                          chunk_sector_size, sectorsize);
                return -EUCLEAN;
        }
        if (unlikely(!length || !IS_ALIGNED(length, sectorsize))) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "invalid chunk length, have %llu", length);
                return -EUCLEAN;
        }
        if (unlikely(check_add_overflow(logical, length, &chunk_end))) {
                chunk_err(fs_info, leaf, chunk, logical,
"invalid chunk logical start and length, have logical start %llu length %llu",
                          logical, length);
                return -EUCLEAN;
        }
        if (unlikely(!is_power_of_2(stripe_len) || stripe_len != BTRFS_STRIPE_LEN)) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "invalid chunk stripe length: %llu",
                          stripe_len);
                return -EUCLEAN;
        }
        /*
         * We artificially limit the chunk size, so that the number of stripes
         * inside a chunk can be fit into a U32.  The current limit (256G) is
         * way too large for real world usage anyway, and it's also much larger
         * than our existing limit (10G).
         *
         * Thus it should be a good way to catch obvious bitflips.
         */
        if (unlikely(length >= btrfs_stripe_nr_to_offset(U32_MAX))) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "chunk length too large: have %llu limit %llu",
                          length, btrfs_stripe_nr_to_offset(U32_MAX));
                return -EUCLEAN;
        }
        if (unlikely(type & ~BTRFS_BLOCK_GROUP_VALID)) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "unrecognized chunk type: 0x%llx",
                          type & ~BTRFS_BLOCK_GROUP_VALID);
                return -EUCLEAN;
        }

        if (unlikely(!has_single_bit_set(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
                     (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0)) {
                chunk_err(fs_info, leaf, chunk, logical,
                "invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set",
                          type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
                return -EUCLEAN;
        }
        if (unlikely((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0)) {
                chunk_err(fs_info, leaf, chunk, logical,
        "missing chunk type flag, have 0x%llx one bit must be set in 0x%llx",
                          type, BTRFS_BLOCK_GROUP_TYPE_MASK);
                return -EUCLEAN;
        }

        if (unlikely((type & BTRFS_BLOCK_GROUP_SYSTEM) &&
                     (type & (BTRFS_BLOCK_GROUP_METADATA |
                              BTRFS_BLOCK_GROUP_DATA)))) {
                chunk_err(fs_info, leaf, chunk, logical,
                          "system chunk with data or metadata type: 0x%llx",
                          type);
                return -EUCLEAN;
        }

        features = btrfs_super_incompat_flags(fs_info->super_copy);
        if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
                mixed = true;

        if (!mixed) {
                if (unlikely((type & BTRFS_BLOCK_GROUP_METADATA) &&
                             (type & BTRFS_BLOCK_GROUP_DATA))) {
                        chunk_err(fs_info, leaf, chunk, logical,
                        "mixed chunk type in non-mixed mode: 0x%llx", type);
                        return -EUCLEAN;
                }
        }

        if (!remapped &&
            !valid_stripe_count(type & BTRFS_BLOCK_GROUP_PROFILE_MASK,
                                num_stripes, sub_stripes)) {
                chunk_err(fs_info, leaf, chunk, logical,
                        "invalid num_stripes:sub_stripes %u:%u for profile %llu",
                        num_stripes, sub_stripes,
                        type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
                return -EUCLEAN;
        }

        return 0;
}

/*
 * Enhanced version of chunk item checker.
 *
 * The common btrfs_check_chunk_valid() doesn't check item size since it needs
 * to work on super block sys_chunk_array which doesn't have full item ptr.
 */
static int check_leaf_chunk_item(struct extent_buffer *leaf,
                                 struct btrfs_chunk *chunk,
                                 struct btrfs_key *key, int slot)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        int num_stripes;

        if (unlikely(btrfs_item_size(leaf, slot) < offsetof(struct btrfs_chunk, stripe))) {
                chunk_err(fs_info, leaf, chunk, key->offset,
                        "invalid chunk item size: have %u expect [%zu, %u)",
                        btrfs_item_size(leaf, slot),
                        offsetof(struct btrfs_chunk, stripe),
                        BTRFS_LEAF_DATA_SIZE(fs_info));
                return -EUCLEAN;
        }

        num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
        /* Let btrfs_check_chunk_valid() handle this error type */
        if (num_stripes == 0)
                goto out;

        if (unlikely(btrfs_chunk_item_size(num_stripes) !=
                     btrfs_item_size(leaf, slot))) {
                chunk_err(fs_info, leaf, chunk, key->offset,
                        "invalid chunk item size: have %u expect %lu",
                        btrfs_item_size(leaf, slot),
                        btrfs_chunk_item_size(num_stripes));
                return -EUCLEAN;
        }
out:
        return btrfs_check_chunk_valid(fs_info, leaf, chunk, key->offset,
                                       fs_info->sectorsize);
}

__printf(3, 4)
__cold
static void dev_item_err(const struct extent_buffer *eb, int slot,
                         const char *fmt, ...)
{
        struct btrfs_key key;
        struct va_format vaf;
        va_list args;

        btrfs_item_key_to_cpu(eb, &key, slot);
        va_start(args, fmt);

        vaf.fmt = fmt;
        vaf.va = &args;

        dump_page(folio_page(eb->folios[0], 0), "eb page dump");
        btrfs_crit(eb->fs_info,
        "corrupt %s: root=%llu block=%llu slot=%d devid=%llu %pV",
                btrfs_header_level(eb) == 0 ? "leaf" : "node",
                btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
                key.objectid, &vaf);
        va_end(args);
}

static int check_dev_item(struct extent_buffer *leaf,
                          struct btrfs_key *key, int slot)
{
        struct btrfs_dev_item *ditem;
        const u32 item_size = btrfs_item_size(leaf, slot);

        if (unlikely(key->objectid != BTRFS_DEV_ITEMS_OBJECTID)) {
                dev_item_err(leaf, slot,
                             "invalid objectid: has=%llu expect=%llu",
                             key->objectid, BTRFS_DEV_ITEMS_OBJECTID);
                return -EUCLEAN;
        }

        if (unlikely(item_size != sizeof(*ditem))) {
                dev_item_err(leaf, slot, "invalid item size: has %u expect %zu",
                             item_size, sizeof(*ditem));
                return -EUCLEAN;
        }

        ditem = btrfs_item_ptr(leaf, slot, struct btrfs_dev_item);
        if (unlikely(btrfs_device_id(leaf, ditem) != key->offset)) {
                dev_item_err(leaf, slot,
                             "devid mismatch: key has=%llu item has=%llu",
                             key->offset, btrfs_device_id(leaf, ditem));
                return -EUCLEAN;
        }

        /*
         * For device total_bytes, we don't have reliable way to check it, as
         * it can be 0 for device removal. Device size check can only be done
         * by dev extents check.
         */
        if (unlikely(btrfs_device_bytes_used(leaf, ditem) >
                     btrfs_device_total_bytes(leaf, ditem))) {
                dev_item_err(leaf, slot,
                             "invalid bytes used: have %llu expect [0, %llu]",
                             btrfs_device_bytes_used(leaf, ditem),
                             btrfs_device_total_bytes(leaf, ditem));
                return -EUCLEAN;
        }
        /*
         * Remaining members like io_align/type/gen/dev_group aren't really
         * utilized.  Skip them to make later usage of them easier.
         */
        return 0;
}

static int check_inode_item(struct extent_buffer *leaf,
                            struct btrfs_key *key, int slot)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        struct btrfs_inode_item *iitem;
        u64 super_gen = btrfs_super_generation(fs_info->super_copy);
        u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
        const u32 item_size = btrfs_item_size(leaf, slot);
        u32 mode;
        int ret;
        u32 flags;
        u32 ro_flags;

        ret = check_inode_key(leaf, key, slot);
        if (unlikely(ret < 0))
                return ret;

        if (unlikely(item_size != sizeof(*iitem))) {
                generic_err(leaf, slot, "invalid item size: has %u expect %zu",
                            item_size, sizeof(*iitem));
                return -EUCLEAN;
        }

        iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);

        /* Here we use super block generation + 1 to handle log tree */
        if (unlikely(btrfs_inode_generation(leaf, iitem) > super_gen + 1)) {
                inode_item_err(leaf, slot,
                        "invalid inode generation: has %llu expect (0, %llu]",
                               btrfs_inode_generation(leaf, iitem),
                               super_gen + 1);
                return -EUCLEAN;
        }
        /* Note for ROOT_TREE_DIR_ITEM, mkfs could set its transid 0 */
        if (unlikely(btrfs_inode_transid(leaf, iitem) > super_gen + 1)) {
                inode_item_err(leaf, slot,
                        "invalid inode transid: has %llu expect [0, %llu]",
                               btrfs_inode_transid(leaf, iitem), super_gen + 1);
                return -EUCLEAN;
        }

        /*
         * For size and nbytes it's better not to be too strict, as for dir
         * item its size/nbytes can easily get wrong, but doesn't affect
         * anything in the fs. So here we skip the check.
         */
        mode = btrfs_inode_mode(leaf, iitem);
        if (unlikely(mode & ~valid_mask)) {
                inode_item_err(leaf, slot,
                               "unknown mode bit detected: 0x%x",
                               mode & ~valid_mask);
                return -EUCLEAN;
        }

        /*
         * S_IFMT is not bit mapped so we can't completely rely on
         * is_power_of_2/has_single_bit_set, but it can save us from checking
         * FIFO/CHR/DIR/REG.  Only needs to check BLK, LNK and SOCKS
         */
        if (!has_single_bit_set(mode & S_IFMT)) {
                if (unlikely(!S_ISLNK(mode) && !S_ISBLK(mode) && !S_ISSOCK(mode))) {
                        inode_item_err(leaf, slot,
                        "invalid mode: has 0%o expect valid S_IF* bit(s)",
                                       mode & S_IFMT);
                        return -EUCLEAN;
                }
        }
        if (unlikely(S_ISDIR(mode) && btrfs_inode_nlink(leaf, iitem) > 1)) {
                inode_item_err(leaf, slot,
                       "invalid nlink: has %u expect no more than 1 for dir",
                        btrfs_inode_nlink(leaf, iitem));
                return -EUCLEAN;
        }
        btrfs_inode_split_flags(btrfs_inode_flags(leaf, iitem), &flags, &ro_flags);
        if (unlikely(flags & ~BTRFS_INODE_FLAG_MASK)) {
                inode_item_err(leaf, slot,
                               "unknown incompat flags detected: 0x%x", flags);
                return -EUCLEAN;
        }
        if (unlikely(!sb_rdonly(fs_info->sb) &&
                     (ro_flags & ~BTRFS_INODE_RO_FLAG_MASK))) {
                inode_item_err(leaf, slot,
                        "unknown ro-compat flags detected on writeable mount: 0x%x",
                        ro_flags);
                return -EUCLEAN;
        }
        return 0;
}

static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
                           int slot)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        struct btrfs_root_item ri = { 0 };
        const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY |
                                     BTRFS_ROOT_SUBVOL_DEAD;
        int ret;

        ret = check_root_key(leaf, key, slot);
        if (unlikely(ret < 0))
                return ret;

        if (unlikely(btrfs_item_size(leaf, slot) != sizeof(ri) &&
                     btrfs_item_size(leaf, slot) !=
                     btrfs_legacy_root_item_size())) {
                generic_err(leaf, slot,
                            "invalid root item size, have %u expect %zu or %u",
                            btrfs_item_size(leaf, slot), sizeof(ri),
                            btrfs_legacy_root_item_size());
                return -EUCLEAN;
        }

        /*
         * For legacy root item, the members starting at generation_v2 will be
         * all filled with 0.
         * And since we allow generation_v2 as 0, it will still pass the check.
         */
        read_extent_buffer(leaf, &ri, btrfs_item_ptr_offset(leaf, slot),
                           btrfs_item_size(leaf, slot));

        /* Generation related */
        if (unlikely(btrfs_root_generation(&ri) >
                     btrfs_super_generation(fs_info->super_copy) + 1)) {
                generic_err(leaf, slot,
                        "invalid root generation, have %llu expect (0, %llu]",
                            btrfs_root_generation(&ri),
                            btrfs_super_generation(fs_info->super_copy) + 1);
                return -EUCLEAN;
        }
        if (unlikely(btrfs_root_generation_v2(&ri) >
                     btrfs_super_generation(fs_info->super_copy) + 1)) {
                generic_err(leaf, slot,
                "invalid root v2 generation, have %llu expect (0, %llu]",
                            btrfs_root_generation_v2(&ri),
                            btrfs_super_generation(fs_info->super_copy) + 1);
                return -EUCLEAN;
        }
        if (unlikely(btrfs_root_last_snapshot(&ri) >
                     btrfs_super_generation(fs_info->super_copy) + 1)) {
                generic_err(leaf, slot,
                "invalid root last_snapshot, have %llu expect (0, %llu]",
                            btrfs_root_last_snapshot(&ri),
                            btrfs_super_generation(fs_info->super_copy) + 1);
                return -EUCLEAN;
        }

        /* Alignment and level check */
        if (unlikely(!IS_ALIGNED(btrfs_root_bytenr(&ri), fs_info->sectorsize))) {
                generic_err(leaf, slot,
                "invalid root bytenr, have %llu expect to be aligned to %u",
                            btrfs_root_bytenr(&ri), fs_info->sectorsize);
                return -EUCLEAN;
        }
        if (unlikely(btrfs_root_level(&ri) >= BTRFS_MAX_LEVEL)) {
                generic_err(leaf, slot,
                            "invalid root level, have %u expect [0, %u]",
                            btrfs_root_level(&ri), BTRFS_MAX_LEVEL - 1);
                return -EUCLEAN;
        }
        if (unlikely(btrfs_root_drop_level(&ri) >= BTRFS_MAX_LEVEL)) {
                generic_err(leaf, slot,
                            "invalid root drop_level, have %u expect [0, %u]",
                            btrfs_root_drop_level(&ri), BTRFS_MAX_LEVEL - 1);
                return -EUCLEAN;
        }
        /*
         * If drop_progress.objectid is non-zero, a btrfs_drop_snapshot() was
         * interrupted and the resume point was recorded in drop_progress and
         * drop_level.  In that case drop_level must be >= 1: level 0 is the
         * leaf level and drop_snapshot never saves a checkpoint there (it
         * only records checkpoints at internal node levels in DROP_REFERENCE
         * stage).  A zero drop_level combined with a non-zero drop_progress
         * objectid indicates on-disk corruption and would cause a BUG_ON in
         * merge_reloc_root() and btrfs_drop_snapshot() at mount time.
         */
        if (unlikely(btrfs_disk_key_objectid(&ri.drop_progress) != 0 &&
                     btrfs_root_drop_level(&ri) == 0)) {
                generic_err(leaf, slot,
                            "invalid root drop_level 0 with non-zero drop_progress objectid %llu",
                            btrfs_disk_key_objectid(&ri.drop_progress));
                return -EUCLEAN;
        }

        /* Flags check */
        if (unlikely(btrfs_root_flags(&ri) & ~valid_root_flags)) {
                generic_err(leaf, slot,
                            "invalid root flags, have 0x%llx expect mask 0x%llx",
                            btrfs_root_flags(&ri), valid_root_flags);
                return -EUCLEAN;
        }
        return 0;
}

__printf(3,4)
__cold
static void extent_err(const struct extent_buffer *eb, int slot,
                       const char *fmt, ...)
{
        struct btrfs_key key;
        struct va_format vaf;
        va_list args;
        u64 bytenr;
        u64 len;

        btrfs_item_key_to_cpu(eb, &key, slot);
        bytenr = key.objectid;
        if (key.type == BTRFS_METADATA_ITEM_KEY ||
            key.type == BTRFS_TREE_BLOCK_REF_KEY ||
            key.type == BTRFS_SHARED_BLOCK_REF_KEY)
                len = eb->fs_info->nodesize;
        else
                len = key.offset;
        va_start(args, fmt);

        vaf.fmt = fmt;
        vaf.va = &args;

        dump_page(folio_page(eb->folios[0], 0), "eb page dump");
        btrfs_crit(eb->fs_info,
        "corrupt %s: block=%llu slot=%d extent bytenr=%llu len=%llu %pV",
                btrfs_header_level(eb) == 0 ? "leaf" : "node",
                eb->start, slot, bytenr, len, &vaf);
        va_end(args);
}

static bool is_valid_dref_root(u64 rootid)
{
        /*
         * The following tree root objectids are allowed to have a data backref:
         * - subvolume trees
         * - data reloc tree
         * - tree root
         *   For v1 space cache
         */
        return btrfs_is_fstree(rootid) || rootid == BTRFS_DATA_RELOC_TREE_OBJECTID ||
               rootid == BTRFS_ROOT_TREE_OBJECTID;
}

static int check_extent_item(struct extent_buffer *leaf,
                             struct btrfs_key *key, int slot,
                             struct btrfs_key *prev_key)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        struct btrfs_extent_item *ei;
        bool is_tree_block = false;
        unsigned long ptr;      /* Current pointer inside inline refs */
        unsigned long end;      /* Extent item end */
        const u32 item_size = btrfs_item_size(leaf, slot);
        u8 last_type = 0;
        u64 last_seq = U64_MAX;
        u64 flags;
        u64 generation;
        u64 total_refs;         /* Total refs in btrfs_extent_item */
        u64 inline_refs = 0;    /* found total inline refs */

        if (unlikely(key->type == BTRFS_METADATA_ITEM_KEY &&
                     !btrfs_fs_incompat(fs_info, SKINNY_METADATA))) {
                generic_err(leaf, slot,
"invalid key type, METADATA_ITEM type invalid when SKINNY_METADATA feature disabled");
                return -EUCLEAN;
        }
        /* key->objectid is the bytenr for both key types */
        if (unlikely(!IS_ALIGNED(key->objectid, fs_info->sectorsize))) {
                generic_err(leaf, slot,
                "invalid key objectid, have %llu expect to be aligned to %u",
                           key->objectid, fs_info->sectorsize);
                return -EUCLEAN;
        }

        /* key->offset is tree level for METADATA_ITEM_KEY */
        if (unlikely(key->type == BTRFS_METADATA_ITEM_KEY &&
                     key->offset >= BTRFS_MAX_LEVEL)) {
                extent_err(leaf, slot,
                           "invalid tree level, have %llu expect [0, %u]",
                           key->offset, BTRFS_MAX_LEVEL - 1);
                return -EUCLEAN;
        }

        /*
         * EXTENT/METADATA_ITEM consists of:
         * 1) One btrfs_extent_item
         *    Records the total refs, type and generation of the extent.
         *
         * 2) One btrfs_tree_block_info (for EXTENT_ITEM and tree backref only)
         *    Records the first key and level of the tree block.
         *
         * 2) Zero or more btrfs_extent_inline_ref(s)
         *    Each inline ref has one btrfs_extent_inline_ref shows:
         *    2.1) The ref type, one of the 4
         *         TREE_BLOCK_REF       Tree block only
         *         SHARED_BLOCK_REF     Tree block only
         *         EXTENT_DATA_REF      Data only
         *         SHARED_DATA_REF      Data only
         *    2.2) Ref type specific data
         *         Either using btrfs_extent_inline_ref::offset, or specific
         *         data structure.
         *
         *    All above inline items should follow the order:
         *
         *    - All btrfs_extent_inline_ref::type should be in an ascending
         *      order
         *
         *    - Within the same type, the items should follow a descending
         *      order by their sequence number. The sequence number is
         *      determined by:
         *      * btrfs_extent_inline_ref::offset for all types  other than
         *        EXTENT_DATA_REF
         *      * hash_extent_data_ref() for EXTENT_DATA_REF
         */
        if (unlikely(item_size < sizeof(*ei))) {
                extent_err(leaf, slot,
                           "invalid item size, have %u expect [%zu, %u)",
                           item_size, sizeof(*ei),
                           BTRFS_LEAF_DATA_SIZE(fs_info));
                return -EUCLEAN;
        }
        end = item_size + btrfs_item_ptr_offset(leaf, slot);

        /* Checks against extent_item */
        ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
        flags = btrfs_extent_flags(leaf, ei);
        total_refs = btrfs_extent_refs(leaf, ei);
        generation = btrfs_extent_generation(leaf, ei);
        if (unlikely(generation >
                     btrfs_super_generation(fs_info->super_copy) + 1)) {
                extent_err(leaf, slot,
                           "invalid generation, have %llu expect (0, %llu]",
                           generation,
                           btrfs_super_generation(fs_info->super_copy) + 1);
                return -EUCLEAN;
        }
        if (unlikely(!has_single_bit_set(flags & (BTRFS_EXTENT_FLAG_DATA |
                                                  BTRFS_EXTENT_FLAG_TREE_BLOCK)))) {
                extent_err(leaf, slot,
                "invalid extent flag, have 0x%llx expect 1 bit set in 0x%llx",
                        flags, BTRFS_EXTENT_FLAG_DATA |
                        BTRFS_EXTENT_FLAG_TREE_BLOCK);
                return -EUCLEAN;
        }
        is_tree_block = !!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK);
        if (is_tree_block) {
                if (unlikely(key->type == BTRFS_EXTENT_ITEM_KEY &&
                             key->offset != fs_info->nodesize)) {
                        extent_err(leaf, slot,
                                   "invalid extent length, have %llu expect %u",
                                   key->offset, fs_info->nodesize);
                        return -EUCLEAN;
                }
        } else {
                if (unlikely(key->type != BTRFS_EXTENT_ITEM_KEY)) {
                        extent_err(leaf, slot,
                        "invalid key type, have %u expect %u for data backref",
                                   key->type, BTRFS_EXTENT_ITEM_KEY);
                        return -EUCLEAN;
                }
                if (unlikely(!IS_ALIGNED(key->offset, fs_info->sectorsize))) {
                        extent_err(leaf, slot,
                        "invalid extent length, have %llu expect aligned to %u",
                                   key->offset, fs_info->sectorsize);
                        return -EUCLEAN;
                }
                if (unlikely(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
                        extent_err(leaf, slot,
                        "invalid extent flag, data has full backref set");
                        return -EUCLEAN;
                }
        }
        ptr = (unsigned long)(struct btrfs_extent_item *)(ei + 1);

        /* Check the special case of btrfs_tree_block_info */
        if (is_tree_block && key->type != BTRFS_METADATA_ITEM_KEY) {
                struct btrfs_tree_block_info *info;

                info = (struct btrfs_tree_block_info *)ptr;
                if (unlikely(btrfs_tree_block_level(leaf, info) >= BTRFS_MAX_LEVEL)) {
                        extent_err(leaf, slot,
                        "invalid tree block info level, have %u expect [0, %u]",
                                   btrfs_tree_block_level(leaf, info),
                                   BTRFS_MAX_LEVEL - 1);
                        return -EUCLEAN;
                }
                ptr = (unsigned long)(struct btrfs_tree_block_info *)(info + 1);
        }

        /* Check inline refs */
        while (ptr < end) {
                struct btrfs_extent_inline_ref *iref;
                struct btrfs_extent_data_ref *dref;
                struct btrfs_shared_data_ref *sref;
                u64 seq;
                u64 dref_root;
                u64 dref_objectid;
                u64 dref_offset;
                u64 inline_offset;
                u8 inline_type;

                if (unlikely(ptr + sizeof(*iref) > end)) {
                        extent_err(leaf, slot,
"inline ref item overflows extent item, ptr %lu iref size %zu end %lu",
                                   ptr, sizeof(*iref), end);
                        return -EUCLEAN;
                }
                iref = (struct btrfs_extent_inline_ref *)ptr;
                inline_type = btrfs_extent_inline_ref_type(leaf, iref);
                inline_offset = btrfs_extent_inline_ref_offset(leaf, iref);
                seq = inline_offset;
                if (unlikely(ptr + btrfs_extent_inline_ref_size(inline_type) > end)) {
                        extent_err(leaf, slot,
"inline ref item overflows extent item, ptr %lu iref size %u end %lu",
                                   ptr, btrfs_extent_inline_ref_size(inline_type), end);
                        return -EUCLEAN;
                }

                switch (inline_type) {
                /* inline_offset is subvolid of the owner, no need to check */
                case BTRFS_TREE_BLOCK_REF_KEY:
                        inline_refs++;
                        break;
                /* Contains parent bytenr */
                case BTRFS_SHARED_BLOCK_REF_KEY:
                        if (unlikely(!IS_ALIGNED(inline_offset,
                                                 fs_info->sectorsize))) {
                                extent_err(leaf, slot,
                "invalid tree parent bytenr, have %llu expect aligned to %u",
                                           inline_offset, fs_info->sectorsize);
                                return -EUCLEAN;
                        }
                        inline_refs++;
                        break;
                /*
                 * Contains owner subvolid, owner key objectid, adjusted offset.
                 * The only obvious corruption can happen in that offset.
                 */
                case BTRFS_EXTENT_DATA_REF_KEY:
                        dref = (struct btrfs_extent_data_ref *)(&iref->offset);
                        dref_root = btrfs_extent_data_ref_root(leaf, dref);
                        dref_objectid = btrfs_extent_data_ref_objectid(leaf, dref);
                        dref_offset = btrfs_extent_data_ref_offset(leaf, dref);
                        seq = hash_extent_data_ref(
                                        btrfs_extent_data_ref_root(leaf, dref),
                                        btrfs_extent_data_ref_objectid(leaf, dref),
                                        btrfs_extent_data_ref_offset(leaf, dref));
                        if (unlikely(!is_valid_dref_root(dref_root))) {
                                extent_err(leaf, slot,
                                           "invalid data ref root value %llu",
                                           dref_root);
                                return -EUCLEAN;
                        }
                        if (unlikely(dref_objectid < BTRFS_FIRST_FREE_OBJECTID ||
                                     dref_objectid > BTRFS_LAST_FREE_OBJECTID)) {
                                extent_err(leaf, slot,
                                           "invalid data ref objectid value %llu",
                                           dref_objectid);
                                return -EUCLEAN;
                        }
                        if (unlikely(!IS_ALIGNED(dref_offset,
                                                 fs_info->sectorsize))) {
                                extent_err(leaf, slot,
                "invalid data ref offset, have %llu expect aligned to %u",
                                           dref_offset, fs_info->sectorsize);
                                return -EUCLEAN;
                        }
                        if (unlikely(btrfs_extent_data_ref_count(leaf, dref) == 0)) {
                                extent_err(leaf, slot,
                        "invalid data ref count, should have non-zero value");
                                return -EUCLEAN;
                        }
                        inline_refs += btrfs_extent_data_ref_count(leaf, dref);
                        break;
                /* Contains parent bytenr and ref count */
                case BTRFS_SHARED_DATA_REF_KEY:
                        sref = (struct btrfs_shared_data_ref *)(iref + 1);
                        if (unlikely(!IS_ALIGNED(inline_offset,
                                                 fs_info->sectorsize))) {
                                extent_err(leaf, slot,
                "invalid data parent bytenr, have %llu expect aligned to %u",
                                           inline_offset, fs_info->sectorsize);
                                return -EUCLEAN;
                        }
                        if (unlikely(btrfs_shared_data_ref_count(leaf, sref) == 0)) {
                                extent_err(leaf, slot,
                        "invalid shared data ref count, should have non-zero value");
                                return -EUCLEAN;
                        }
                        inline_refs += btrfs_shared_data_ref_count(leaf, sref);
                        break;
                case BTRFS_EXTENT_OWNER_REF_KEY:
                        WARN_ON(!btrfs_fs_incompat(fs_info, SIMPLE_QUOTA));
                        break;
                default:
                        extent_err(leaf, slot, "unknown inline ref type: %u",
                                   inline_type);
                        return -EUCLEAN;
                }
                if (unlikely(inline_type < last_type)) {
                        extent_err(leaf, slot,
                                   "inline ref out-of-order: has type %u, prev type %u",
                                   inline_type, last_type);
                        return -EUCLEAN;
                }
                /* Type changed, allow the sequence starts from U64_MAX again. */
                if (inline_type > last_type)
                        last_seq = U64_MAX;
                if (unlikely(seq > last_seq)) {
                        extent_err(leaf, slot,
"inline ref out-of-order: has type %u offset %llu seq 0x%llx, prev type %u seq 0x%llx",
                                   inline_type, inline_offset, seq,
                                   last_type, last_seq);
                        return -EUCLEAN;
                }
                last_type = inline_type;
                last_seq = seq;
                ptr += btrfs_extent_inline_ref_size(inline_type);
        }
        /* No padding is allowed */
        if (unlikely(ptr != end)) {
                extent_err(leaf, slot,
                           "invalid extent item size, padding bytes found");
                return -EUCLEAN;
        }

        /* Finally, check the inline refs against total refs */
        if (unlikely(inline_refs > total_refs)) {
                extent_err(leaf, slot,
                        "invalid extent refs, have %llu expect >= inline %llu",
                           total_refs, inline_refs);
                return -EUCLEAN;
        }

        if ((prev_key->type == BTRFS_EXTENT_ITEM_KEY) ||
            (prev_key->type == BTRFS_METADATA_ITEM_KEY)) {
                u64 prev_end = prev_key->objectid;

                if (prev_key->type == BTRFS_METADATA_ITEM_KEY)
                        prev_end += fs_info->nodesize;
                else
                        prev_end += prev_key->offset;

                if (unlikely(prev_end > key->objectid)) {
                        extent_err(leaf, slot,
        "previous extent " BTRFS_KEY_FMT " overlaps current extent " BTRFS_KEY_FMT,
                                   BTRFS_KEY_FMT_VALUE(prev_key),
                                   BTRFS_KEY_FMT_VALUE(key));
                        return -EUCLEAN;
                }
        }

        return 0;
}

static int check_simple_keyed_refs(struct extent_buffer *leaf,
                                   struct btrfs_key *key, int slot)
{
        u32 expect_item_size = 0;

        if (key->type == BTRFS_SHARED_DATA_REF_KEY) {
                struct btrfs_shared_data_ref *sref;

                sref = btrfs_item_ptr(leaf, slot, struct btrfs_shared_data_ref);
                if (unlikely(btrfs_shared_data_ref_count(leaf, sref) == 0)) {
                        extent_err(leaf, slot,
                "invalid shared data backref count, should have non-zero value");
                        return -EUCLEAN;
                }

                expect_item_size = sizeof(struct btrfs_shared_data_ref);
        }

        if (unlikely(btrfs_item_size(leaf, slot) != expect_item_size)) {
                generic_err(leaf, slot,
                "invalid item size, have %u expect %u for key type %u",
                            btrfs_item_size(leaf, slot),
                            expect_item_size, key->type);
                return -EUCLEAN;
        }
        if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
                generic_err(leaf, slot,
"invalid key objectid for shared block ref, have %llu expect aligned to %u",
                            key->objectid, leaf->fs_info->sectorsize);
                return -EUCLEAN;
        }
        if (unlikely(key->type != BTRFS_TREE_BLOCK_REF_KEY &&
                     !IS_ALIGNED(key->offset, leaf->fs_info->sectorsize))) {
                extent_err(leaf, slot,
                "invalid tree parent bytenr, have %llu expect aligned to %u",
                           key->offset, leaf->fs_info->sectorsize);
                return -EUCLEAN;
        }
        return 0;
}

static int check_extent_data_ref(struct extent_buffer *leaf,
                                 struct btrfs_key *key, int slot)
{
        struct btrfs_extent_data_ref *dref;
        unsigned long ptr = btrfs_item_ptr_offset(leaf, slot);
        const unsigned long end = ptr + btrfs_item_size(leaf, slot);

        if (unlikely(btrfs_item_size(leaf, slot) % sizeof(*dref) != 0)) {
                generic_err(leaf, slot,
        "invalid item size, have %u expect aligned to %zu for key type %u",
                            btrfs_item_size(leaf, slot),
                            sizeof(*dref), key->type);
                return -EUCLEAN;
        }
        if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
                generic_err(leaf, slot,
"invalid key objectid for shared block ref, have %llu expect aligned to %u",
                            key->objectid, leaf->fs_info->sectorsize);
                return -EUCLEAN;
        }
        for (; ptr < end; ptr += sizeof(*dref)) {
                u64 root;
                u64 objectid;
                u64 offset;

                /*
                 * We cannot check the extent_data_ref hash due to possible
                 * overflow from the leaf due to hash collisions.
                 */
                dref = (struct btrfs_extent_data_ref *)ptr;
                root = btrfs_extent_data_ref_root(leaf, dref);
                objectid = btrfs_extent_data_ref_objectid(leaf, dref);
                offset = btrfs_extent_data_ref_offset(leaf, dref);
                if (unlikely(!is_valid_dref_root(root))) {
                        extent_err(leaf, slot,
                                   "invalid extent data backref root value %llu",
                                   root);
                        return -EUCLEAN;
                }
                if (unlikely(objectid < BTRFS_FIRST_FREE_OBJECTID ||
                             objectid > BTRFS_LAST_FREE_OBJECTID)) {
                        extent_err(leaf, slot,
                                   "invalid extent data backref objectid value %llu",
                                   objectid);
                        return -EUCLEAN;
                }
                if (unlikely(!IS_ALIGNED(offset, leaf->fs_info->sectorsize))) {
                        extent_err(leaf, slot,
        "invalid extent data backref offset, have %llu expect aligned to %u",
                                   offset, leaf->fs_info->sectorsize);
                        return -EUCLEAN;
                }
                if (unlikely(btrfs_extent_data_ref_count(leaf, dref) == 0)) {
                        extent_err(leaf, slot,
        "invalid extent data backref count, should have non-zero value");
                        return -EUCLEAN;
                }
        }
        return 0;
}

#define inode_ref_err(eb, slot, fmt, args...)                   \
        inode_item_err(eb, slot, fmt, ##args)
static int check_inode_ref(struct extent_buffer *leaf,
                           struct btrfs_key *key, struct btrfs_key *prev_key,
                           int slot)
{
        struct btrfs_inode_ref *iref;
        unsigned long ptr;
        unsigned long end;

        if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
                return -EUCLEAN;
        /* namelen can't be 0, so item_size == sizeof() is also invalid */
        if (unlikely(btrfs_item_size(leaf, slot) <= sizeof(*iref))) {
                inode_ref_err(leaf, slot,
                        "invalid item size, have %u expect (%zu, %u)",
                        btrfs_item_size(leaf, slot),
                        sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
                return -EUCLEAN;
        }

        ptr = btrfs_item_ptr_offset(leaf, slot);
        end = ptr + btrfs_item_size(leaf, slot);
        while (ptr < end) {
                u16 namelen;

                if (unlikely(ptr + sizeof(*iref) > end)) {
                        inode_ref_err(leaf, slot,
                        "inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
                                ptr, end, sizeof(*iref));
                        return -EUCLEAN;
                }

                iref = (struct btrfs_inode_ref *)ptr;
                namelen = btrfs_inode_ref_name_len(leaf, iref);
                if (unlikely(ptr + sizeof(*iref) + namelen > end)) {
                        inode_ref_err(leaf, slot,
                                "inode ref overflow, ptr %lu end %lu namelen %u",
                                ptr, end, namelen);
                        return -EUCLEAN;
                }

                /*
                 * NOTE: In theory we should record all found index numbers
                 * to find any duplicated indexes, but that will be too time
                 * consuming for inodes with too many hard links.
                 */
                ptr += sizeof(*iref) + namelen;
        }
        return 0;
}

static int check_inode_extref(struct extent_buffer *leaf,
                              struct btrfs_key *key, struct btrfs_key *prev_key,
                              int slot)
{
        unsigned long ptr = btrfs_item_ptr_offset(leaf, slot);
        unsigned long end = ptr + btrfs_item_size(leaf, slot);

        if (unlikely(!check_prev_ino(leaf, key, slot, prev_key)))
                return -EUCLEAN;

        while (ptr < end) {
                struct btrfs_inode_extref *extref = (struct btrfs_inode_extref *)ptr;
                u16 namelen;

                if (unlikely(ptr + sizeof(*extref) > end)) {
                        inode_ref_err(leaf, slot,
                        "inode extref overflow, ptr %lu end %lu inode_extref size %zu",
                                      ptr, end, sizeof(*extref));
                        return -EUCLEAN;
                }

                namelen = btrfs_inode_extref_name_len(leaf, extref);
                if (unlikely(ptr + sizeof(*extref) + namelen > end)) {
                        inode_ref_err(leaf, slot,
                                "inode extref overflow, ptr %lu end %lu namelen %u",
                                ptr, end, namelen);
                        return -EUCLEAN;
                }
                ptr += sizeof(*extref) + namelen;
        }
        return 0;
}

static int check_raid_stripe_extent(const struct extent_buffer *leaf,
                                    const struct btrfs_key *key, int slot)
{
        if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
                generic_err(leaf, slot,
"invalid key objectid for raid stripe extent, have %llu expect aligned to %u",
                            key->objectid, leaf->fs_info->sectorsize);
                return -EUCLEAN;
        }

        if (unlikely(!btrfs_fs_incompat(leaf->fs_info, RAID_STRIPE_TREE))) {
                generic_err(leaf, slot,
        "RAID_STRIPE_EXTENT present but RAID_STRIPE_TREE incompat bit unset");
                return -EUCLEAN;
        }

        return 0;
}

static int check_dev_extent_item(const struct extent_buffer *leaf,
                                 const struct btrfs_key *key,
                                 int slot,
                                 struct btrfs_key *prev_key)
{
        struct btrfs_dev_extent *de;
        const u32 sectorsize = leaf->fs_info->sectorsize;

        de = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent);
        /* Basic fixed member checks. */
        if (unlikely(btrfs_dev_extent_chunk_tree(leaf, de) !=
                     BTRFS_CHUNK_TREE_OBJECTID)) {
                generic_err(leaf, slot,
                            "invalid dev extent chunk tree id, has %llu expect %llu",
                            btrfs_dev_extent_chunk_tree(leaf, de),
                            BTRFS_CHUNK_TREE_OBJECTID);
                return -EUCLEAN;
        }
        if (unlikely(btrfs_dev_extent_chunk_objectid(leaf, de) !=
                     BTRFS_FIRST_CHUNK_TREE_OBJECTID)) {
                generic_err(leaf, slot,
                            "invalid dev extent chunk objectid, has %llu expect %llu",
                            btrfs_dev_extent_chunk_objectid(leaf, de),
                            BTRFS_FIRST_CHUNK_TREE_OBJECTID);
                return -EUCLEAN;
        }
        /* Alignment check. */
        if (unlikely(!IS_ALIGNED(key->offset, sectorsize))) {
                generic_err(leaf, slot,
                            "invalid dev extent key.offset, has %llu not aligned to %u",
                            key->offset, sectorsize);
                return -EUCLEAN;
        }
        if (unlikely(!IS_ALIGNED(btrfs_dev_extent_chunk_offset(leaf, de),
                                 sectorsize))) {
                generic_err(leaf, slot,
                            "invalid dev extent chunk offset, has %llu not aligned to %u",
                            btrfs_dev_extent_chunk_objectid(leaf, de),
                            sectorsize);
                return -EUCLEAN;
        }
        if (unlikely(!IS_ALIGNED(btrfs_dev_extent_length(leaf, de),
                                 sectorsize))) {
                generic_err(leaf, slot,
                            "invalid dev extent length, has %llu not aligned to %u",
                            btrfs_dev_extent_length(leaf, de), sectorsize);
                return -EUCLEAN;
        }
        /* Overlap check with previous dev extent. */
        if (slot && prev_key->objectid == key->objectid &&
            prev_key->type == key->type) {
                struct btrfs_dev_extent *prev_de;
                u64 prev_len;

                prev_de = btrfs_item_ptr(leaf, slot - 1, struct btrfs_dev_extent);
                prev_len = btrfs_dev_extent_length(leaf, prev_de);
                if (unlikely(prev_key->offset + prev_len > key->offset)) {
                        generic_err(leaf, slot,
                "dev extent overlap, prev offset %llu len %llu current offset %llu",
                                    prev_key->offset, prev_len, key->offset);
                        return -EUCLEAN;
                }
        }
        return 0;
}

/*
 * Common point to switch the item-specific validation.
 */
static enum btrfs_tree_block_status check_leaf_item(struct extent_buffer *leaf,
                                                    struct btrfs_key *key,
                                                    int slot,
                                                    struct btrfs_key *prev_key)
{
        int ret = 0;
        struct btrfs_chunk *chunk;

        switch (key->type) {
        case BTRFS_EXTENT_DATA_KEY:
                ret = check_extent_data_item(leaf, key, slot, prev_key);
                break;
        case BTRFS_EXTENT_CSUM_KEY:
                ret = check_csum_item(leaf, key, slot, prev_key);
                break;
        case BTRFS_DIR_ITEM_KEY:
        case BTRFS_DIR_INDEX_KEY:
        case BTRFS_XATTR_ITEM_KEY:
                ret = check_dir_item(leaf, key, prev_key, slot);
                break;
        case BTRFS_INODE_REF_KEY:
                ret = check_inode_ref(leaf, key, prev_key, slot);
                break;
        case BTRFS_INODE_EXTREF_KEY:
                ret = check_inode_extref(leaf, key, prev_key, slot);
                break;
        case BTRFS_BLOCK_GROUP_ITEM_KEY:
                ret = check_block_group_item(leaf, key, slot);
                break;
        case BTRFS_CHUNK_ITEM_KEY:
                chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
                ret = check_leaf_chunk_item(leaf, chunk, key, slot);
                break;
        case BTRFS_DEV_ITEM_KEY:
                ret = check_dev_item(leaf, key, slot);
                break;
        case BTRFS_DEV_EXTENT_KEY:
                ret = check_dev_extent_item(leaf, key, slot, prev_key);
                break;
        case BTRFS_INODE_ITEM_KEY:
                ret = check_inode_item(leaf, key, slot);
                break;
        case BTRFS_ROOT_ITEM_KEY:
                ret = check_root_item(leaf, key, slot);
                break;
        case BTRFS_EXTENT_ITEM_KEY:
        case BTRFS_METADATA_ITEM_KEY:
                ret = check_extent_item(leaf, key, slot, prev_key);
                break;
        case BTRFS_TREE_BLOCK_REF_KEY:
        case BTRFS_SHARED_DATA_REF_KEY:
        case BTRFS_SHARED_BLOCK_REF_KEY:
                ret = check_simple_keyed_refs(leaf, key, slot);
                break;
        case BTRFS_EXTENT_DATA_REF_KEY:
                ret = check_extent_data_ref(leaf, key, slot);
                break;
        case BTRFS_RAID_STRIPE_KEY:
                ret = check_raid_stripe_extent(leaf, key, slot);
                break;
        }

        if (unlikely(ret))
                return BTRFS_TREE_BLOCK_INVALID_ITEM;
        return BTRFS_TREE_BLOCK_CLEAN;
}

enum btrfs_tree_block_status __btrfs_check_leaf(struct extent_buffer *leaf)
{
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        /* No valid key type is 0, so all key should be larger than this key */
        struct btrfs_key prev_key = {0, 0, 0};
        struct btrfs_key key;
        u32 nritems = btrfs_header_nritems(leaf);
        int slot;

        if (unlikely(btrfs_header_level(leaf) != 0)) {
                generic_err(leaf, 0,
                        "invalid level for leaf, have %d expect 0",
                        btrfs_header_level(leaf));
                return BTRFS_TREE_BLOCK_INVALID_LEVEL;
        }

        if (unlikely(!btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_WRITTEN))) {
                generic_err(leaf, 0, "invalid flag for leaf, WRITTEN not set");
                return BTRFS_TREE_BLOCK_WRITTEN_NOT_SET;
        }

        /*
         * Extent buffers from a relocation tree have a owner field that
         * corresponds to the subvolume tree they are based on. So just from an
         * extent buffer alone we can not find out what is the id of the
         * corresponding subvolume tree, so we can not figure out if the extent
         * buffer corresponds to the root of the relocation tree or not. So
         * skip this check for relocation trees.
         */
        if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
                u64 owner = btrfs_header_owner(leaf);

                /* These trees must never be empty */
                if (unlikely(owner == BTRFS_ROOT_TREE_OBJECTID ||
                             owner == BTRFS_CHUNK_TREE_OBJECTID ||
                             owner == BTRFS_DEV_TREE_OBJECTID ||
                             owner == BTRFS_FS_TREE_OBJECTID ||
                             owner == BTRFS_DATA_RELOC_TREE_OBJECTID)) {
                        generic_err(leaf, 0,
                        "invalid root, root %llu must never be empty",
                                    owner);
                        return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
                }

                /* Unknown tree */
                if (unlikely(owner == 0)) {
                        generic_err(leaf, 0,
                                "invalid owner, root 0 is not defined");
                        return BTRFS_TREE_BLOCK_INVALID_OWNER;
                }

                /* EXTENT_TREE_V2 can have empty extent trees. */
                if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
                        return BTRFS_TREE_BLOCK_CLEAN;

                if (unlikely(owner == BTRFS_EXTENT_TREE_OBJECTID)) {
                        generic_err(leaf, 0,
                        "invalid root, root %llu must never be empty",
                                    owner);
                        return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
                }

                return BTRFS_TREE_BLOCK_CLEAN;
        }

        if (unlikely(nritems == 0))
                return BTRFS_TREE_BLOCK_CLEAN;

        /*
         * Check the following things to make sure this is a good leaf, and
         * leaf users won't need to bother with similar sanity checks:
         *
         * 1) key ordering
         * 2) item offset and size
         *    No overlap, no hole, all inside the leaf.
         * 3) item content
         *    If possible, do comprehensive sanity check.
         *    NOTE: All checks must only rely on the item data itself.
         */
        for (slot = 0; slot < nritems; slot++) {
                u32 item_end_expected;
                u64 item_data_end;
                enum btrfs_tree_block_status ret;

                btrfs_item_key_to_cpu(leaf, &key, slot);

                /* Make sure the keys are in the right order */
                if (unlikely(btrfs_comp_cpu_keys(&prev_key, &key) >= 0)) {
                        generic_err(leaf, slot,
        "bad key order, prev " BTRFS_KEY_FMT " current " BTRFS_KEY_FMT,
                                    BTRFS_KEY_FMT_VALUE(&prev_key),
                                    BTRFS_KEY_FMT_VALUE(&key));
                        return BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
                }

                item_data_end = (u64)btrfs_item_offset(leaf, slot) +
                                btrfs_item_size(leaf, slot);
                /*
                 * Make sure the offset and ends are right, remember that the
                 * item data starts at the end of the leaf and grows towards the
                 * front.
                 */
                if (slot == 0)
                        item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info);
                else
                        item_end_expected = btrfs_item_offset(leaf,
                                                                 slot - 1);
                if (unlikely(item_data_end != item_end_expected)) {
                        generic_err(leaf, slot,
                                "unexpected item end, have %llu expect %u",
                                item_data_end, item_end_expected);
                        return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
                }

                /*
                 * Check to make sure that we don't point outside of the leaf,
                 * just in case all the items are consistent to each other, but
                 * all point outside of the leaf.
                 */
                if (unlikely(item_data_end > BTRFS_LEAF_DATA_SIZE(fs_info))) {
                        generic_err(leaf, slot,
                        "slot end outside of leaf, have %llu expect range [0, %u]",
                                item_data_end, BTRFS_LEAF_DATA_SIZE(fs_info));
                        return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
                }

                /* Also check if the item pointer overlaps with btrfs item. */
                if (unlikely(btrfs_item_ptr_offset(leaf, slot) <
                             btrfs_item_nr_offset(leaf, slot) + sizeof(struct btrfs_item))) {
                        generic_err(leaf, slot,
                "slot overlaps with its data, item end %lu data start %lu",
                                btrfs_item_nr_offset(leaf, slot) +
                                sizeof(struct btrfs_item),
                                btrfs_item_ptr_offset(leaf, slot));
                        return BTRFS_TREE_BLOCK_INVALID_OFFSETS;
                }

                /* Check if the item size and content meet other criteria. */
                ret = check_leaf_item(leaf, &key, slot, &prev_key);
                if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
                        return ret;

                prev_key.objectid = key.objectid;
                prev_key.type = key.type;
                prev_key.offset = key.offset;
        }

        return BTRFS_TREE_BLOCK_CLEAN;
}

int btrfs_check_leaf(struct extent_buffer *leaf)
{
        enum btrfs_tree_block_status ret;

        ret = __btrfs_check_leaf(leaf);
        if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
                return -EUCLEAN;
        return 0;
}
ALLOW_ERROR_INJECTION(btrfs_check_leaf, ERRNO);

enum btrfs_tree_block_status __btrfs_check_node(struct extent_buffer *node)
{
        struct btrfs_fs_info *fs_info = node->fs_info;
        unsigned long nr = btrfs_header_nritems(node);
        struct btrfs_key key, next_key;
        int slot;
        int level = btrfs_header_level(node);
        u64 bytenr;

        if (unlikely(!btrfs_header_flag(node, BTRFS_HEADER_FLAG_WRITTEN))) {
                generic_err(node, 0, "invalid flag for node, WRITTEN not set");
                return BTRFS_TREE_BLOCK_WRITTEN_NOT_SET;
        }

        if (unlikely(level <= 0 || level >= BTRFS_MAX_LEVEL)) {
                generic_err(node, 0,
                        "invalid level for node, have %d expect [1, %d]",
                        level, BTRFS_MAX_LEVEL - 1);
                return BTRFS_TREE_BLOCK_INVALID_LEVEL;
        }
        if (unlikely(nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info))) {
                btrfs_crit(fs_info,
"corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
                           btrfs_header_owner(node), node->start,
                           nr == 0 ? "small" : "large", nr,
                           BTRFS_NODEPTRS_PER_BLOCK(fs_info));
                return BTRFS_TREE_BLOCK_INVALID_NRITEMS;
        }

        for (slot = 0; slot < nr - 1; slot++) {
                bytenr = btrfs_node_blockptr(node, slot);
                btrfs_node_key_to_cpu(node, &key, slot);
                btrfs_node_key_to_cpu(node, &next_key, slot + 1);

                if (unlikely(!bytenr)) {
                        generic_err(node, slot,
                                "invalid NULL node pointer");
                        return BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
                }
                if (unlikely(!IS_ALIGNED(bytenr, fs_info->sectorsize))) {
                        generic_err(node, slot,
                        "unaligned pointer, have %llu should be aligned to %u",
                                bytenr, fs_info->sectorsize);
                        return BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
                }

                if (unlikely(btrfs_comp_cpu_keys(&key, &next_key) >= 0)) {
                        generic_err(node, slot,
        "bad key order, current " BTRFS_KEY_FMT " next " BTRFS_KEY_FMT,
                                    BTRFS_KEY_FMT_VALUE(&key),
                                    BTRFS_KEY_FMT_VALUE(&next_key));
                        return BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
                }
        }
        return BTRFS_TREE_BLOCK_CLEAN;
}

int btrfs_check_node(struct extent_buffer *node)
{
        enum btrfs_tree_block_status ret;

        ret = __btrfs_check_node(node);
        if (unlikely(ret != BTRFS_TREE_BLOCK_CLEAN))
                return -EUCLEAN;
        return 0;
}
ALLOW_ERROR_INJECTION(btrfs_check_node, ERRNO);

int btrfs_check_eb_owner(const struct extent_buffer *eb, u64 root_owner)
{
        const bool is_subvol = btrfs_is_fstree(root_owner);
        const u64 eb_owner = btrfs_header_owner(eb);

        /*
         * Skip dummy fs, as selftests don't create unique ebs for each dummy
         * root.
         */
        if (btrfs_is_testing(eb->fs_info))
                return 0;
        /*
         * There are several call sites (backref walking, qgroup, and data
         * reloc) passing 0 as @root_owner, as they are not holding the
         * tree root.  In that case, we can not do a reliable ownership check,
         * so just exit.
         */
        if (root_owner == 0)
                return 0;
        /*
         * These trees use key.offset as their owner, our callers don't have
         * the extra capacity to pass key.offset here.  So we just skip them.
         */
        if (root_owner == BTRFS_TREE_LOG_OBJECTID ||
            root_owner == BTRFS_TREE_RELOC_OBJECTID)
                return 0;

        if (!is_subvol) {
                /* For non-subvolume trees, the eb owner should match root owner */
                if (unlikely(root_owner != eb_owner)) {
                        btrfs_crit(eb->fs_info,
"corrupted %s, root=%llu block=%llu owner mismatch, have %llu expect %llu",
                                btrfs_header_level(eb) == 0 ? "leaf" : "node",
                                root_owner, btrfs_header_bytenr(eb), eb_owner,
                                root_owner);
                        return -EUCLEAN;
                }
                return 0;
        }

        /*
         * For subvolume trees, owners can mismatch, but they should all belong
         * to subvolume trees.
         */
        if (unlikely(is_subvol != btrfs_is_fstree(eb_owner))) {
                btrfs_crit(eb->fs_info,
"corrupted %s, root=%llu block=%llu owner mismatch, have %llu expect [%llu, %llu]",
                        btrfs_header_level(eb) == 0 ? "leaf" : "node",
                        root_owner, btrfs_header_bytenr(eb), eb_owner,
                        BTRFS_FIRST_FREE_OBJECTID, BTRFS_LAST_FREE_OBJECTID);
                return -EUCLEAN;
        }
        return 0;
}

int btrfs_verify_level_key(struct extent_buffer *eb,
                           const struct btrfs_tree_parent_check *check)
{
        struct btrfs_fs_info *fs_info = eb->fs_info;
        int found_level;
        struct btrfs_key found_key;
        int ret;

        found_level = btrfs_header_level(eb);
        if (unlikely(found_level != check->level)) {
                DEBUG_WARN();
                btrfs_err(fs_info,
"tree level mismatch detected, bytenr=%llu level expected=%u has=%u",
                          eb->start, check->level, found_level);
                return -EUCLEAN;
        }

        if (!check->has_first_key)
                return 0;

        /*
         * For live tree block (new tree blocks in current transaction),
         * we need proper lock context to avoid race, which is impossible here.
         * So we only checks tree blocks which is read from disk, whose
         * generation <= fs_info->last_trans_committed.
         */
        if (btrfs_header_generation(eb) > btrfs_get_last_trans_committed(fs_info))
                return 0;

        /* We have @first_key, so this @eb must have at least one item */
        if (unlikely(btrfs_header_nritems(eb) == 0)) {
                btrfs_err(fs_info,
                "invalid tree nritems, bytenr=%llu nritems=0 expect >0",
                          eb->start);
                DEBUG_WARN();
                return -EUCLEAN;
        }

        if (found_level)
                btrfs_node_key_to_cpu(eb, &found_key, 0);
        else
                btrfs_item_key_to_cpu(eb, &found_key, 0);

        ret = btrfs_comp_cpu_keys(&check->first_key, &found_key);
        if (unlikely(ret)) {
                DEBUG_WARN();
                btrfs_err(fs_info,
"tree first key mismatch detected, bytenr=%llu parent_transid=%llu key expected=(%llu,%u,%llu) has=(%llu,%u,%llu)",
                          eb->start, check->transid, check->first_key.objectid,
                          check->first_key.type, check->first_key.offset,
                          found_key.objectid, found_key.type,
                          found_key.offset);
        }
        return ret;
}