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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /fs/ext4/block_validity.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'fs/ext4/block_validity.c')
-rw-r--r--fs/ext4/block_validity.c370
1 files changed, 370 insertions, 0 deletions
diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
new file mode 100644
index 000000000..3a31e3d71
--- /dev/null
+++ b/fs/ext4/block_validity.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/block_validity.c
+ *
+ * Copyright (C) 2009
+ * Theodore Ts'o (tytso@mit.edu)
+ *
+ * Track which blocks in the filesystem are metadata blocks that
+ * should never be used as data blocks by files or directories.
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include "ext4.h"
+
+struct ext4_system_zone {
+ struct rb_node node;
+ ext4_fsblk_t start_blk;
+ unsigned int count;
+ u32 ino;
+};
+
+static struct kmem_cache *ext4_system_zone_cachep;
+
+int __init ext4_init_system_zone(void)
+{
+ ext4_system_zone_cachep = KMEM_CACHE(ext4_system_zone, 0);
+ if (ext4_system_zone_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+void ext4_exit_system_zone(void)
+{
+ rcu_barrier();
+ kmem_cache_destroy(ext4_system_zone_cachep);
+}
+
+static inline int can_merge(struct ext4_system_zone *entry1,
+ struct ext4_system_zone *entry2)
+{
+ if ((entry1->start_blk + entry1->count) == entry2->start_blk &&
+ entry1->ino == entry2->ino)
+ return 1;
+ return 0;
+}
+
+static void release_system_zone(struct ext4_system_blocks *system_blks)
+{
+ struct ext4_system_zone *entry, *n;
+
+ rbtree_postorder_for_each_entry_safe(entry, n,
+ &system_blks->root, node)
+ kmem_cache_free(ext4_system_zone_cachep, entry);
+}
+
+/*
+ * Mark a range of blocks as belonging to the "system zone" --- that
+ * is, filesystem metadata blocks which should never be used by
+ * inodes.
+ */
+static int add_system_zone(struct ext4_system_blocks *system_blks,
+ ext4_fsblk_t start_blk,
+ unsigned int count, u32 ino)
+{
+ struct ext4_system_zone *new_entry, *entry;
+ struct rb_node **n = &system_blks->root.rb_node, *node;
+ struct rb_node *parent = NULL, *new_node;
+
+ while (*n) {
+ parent = *n;
+ entry = rb_entry(parent, struct ext4_system_zone, node);
+ if (start_blk < entry->start_blk)
+ n = &(*n)->rb_left;
+ else if (start_blk >= (entry->start_blk + entry->count))
+ n = &(*n)->rb_right;
+ else /* Unexpected overlap of system zones. */
+ return -EFSCORRUPTED;
+ }
+
+ new_entry = kmem_cache_alloc(ext4_system_zone_cachep,
+ GFP_KERNEL);
+ if (!new_entry)
+ return -ENOMEM;
+ new_entry->start_blk = start_blk;
+ new_entry->count = count;
+ new_entry->ino = ino;
+ new_node = &new_entry->node;
+
+ rb_link_node(new_node, parent, n);
+ rb_insert_color(new_node, &system_blks->root);
+
+ /* Can we merge to the left? */
+ node = rb_prev(new_node);
+ if (node) {
+ entry = rb_entry(node, struct ext4_system_zone, node);
+ if (can_merge(entry, new_entry)) {
+ new_entry->start_blk = entry->start_blk;
+ new_entry->count += entry->count;
+ rb_erase(node, &system_blks->root);
+ kmem_cache_free(ext4_system_zone_cachep, entry);
+ }
+ }
+
+ /* Can we merge to the right? */
+ node = rb_next(new_node);
+ if (node) {
+ entry = rb_entry(node, struct ext4_system_zone, node);
+ if (can_merge(new_entry, entry)) {
+ new_entry->count += entry->count;
+ rb_erase(node, &system_blks->root);
+ kmem_cache_free(ext4_system_zone_cachep, entry);
+ }
+ }
+ return 0;
+}
+
+static void debug_print_tree(struct ext4_sb_info *sbi)
+{
+ struct rb_node *node;
+ struct ext4_system_zone *entry;
+ struct ext4_system_blocks *system_blks;
+ int first = 1;
+
+ printk(KERN_INFO "System zones: ");
+ rcu_read_lock();
+ system_blks = rcu_dereference(sbi->s_system_blks);
+ node = rb_first(&system_blks->root);
+ while (node) {
+ entry = rb_entry(node, struct ext4_system_zone, node);
+ printk(KERN_CONT "%s%llu-%llu", first ? "" : ", ",
+ entry->start_blk, entry->start_blk + entry->count - 1);
+ first = 0;
+ node = rb_next(node);
+ }
+ rcu_read_unlock();
+ printk(KERN_CONT "\n");
+}
+
+static int ext4_protect_reserved_inode(struct super_block *sb,
+ struct ext4_system_blocks *system_blks,
+ u32 ino)
+{
+ struct inode *inode;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_map_blocks map;
+ u32 i = 0, num;
+ int err = 0, n;
+
+ if ((ino < EXT4_ROOT_INO) ||
+ (ino > le32_to_cpu(sbi->s_es->s_inodes_count)))
+ return -EINVAL;
+ inode = ext4_iget(sb, ino, EXT4_IGET_SPECIAL);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+ num = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+ while (i < num) {
+ cond_resched();
+ map.m_lblk = i;
+ map.m_len = num - i;
+ n = ext4_map_blocks(NULL, inode, &map, 0);
+ if (n < 0) {
+ err = n;
+ break;
+ }
+ if (n == 0) {
+ i++;
+ } else {
+ err = add_system_zone(system_blks, map.m_pblk, n, ino);
+ if (err < 0) {
+ if (err == -EFSCORRUPTED) {
+ EXT4_ERROR_INODE_ERR(inode, -err,
+ "blocks %llu-%llu from inode overlap system zone",
+ map.m_pblk,
+ map.m_pblk + map.m_len - 1);
+ }
+ break;
+ }
+ i += n;
+ }
+ }
+ iput(inode);
+ return err;
+}
+
+static void ext4_destroy_system_zone(struct rcu_head *rcu)
+{
+ struct ext4_system_blocks *system_blks;
+
+ system_blks = container_of(rcu, struct ext4_system_blocks, rcu);
+ release_system_zone(system_blks);
+ kfree(system_blks);
+}
+
+/*
+ * Build system zone rbtree which is used for block validity checking.
+ *
+ * The update of system_blks pointer in this function is protected by
+ * sb->s_umount semaphore. However we have to be careful as we can be
+ * racing with ext4_inode_block_valid() calls reading system_blks rbtree
+ * protected only by RCU. That's why we first build the rbtree and then
+ * swap it in place.
+ */
+int ext4_setup_system_zone(struct super_block *sb)
+{
+ ext4_group_t ngroups = ext4_get_groups_count(sb);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_system_blocks *system_blks;
+ struct ext4_group_desc *gdp;
+ ext4_group_t i;
+ int ret;
+
+ system_blks = kzalloc_obj(*system_blks);
+ if (!system_blks)
+ return -ENOMEM;
+
+ for (i=0; i < ngroups; i++) {
+ unsigned int meta_blks = ext4_num_base_meta_blocks(sb, i);
+
+ cond_resched();
+ if (meta_blks != 0) {
+ ret = add_system_zone(system_blks,
+ ext4_group_first_block_no(sb, i),
+ meta_blks, 0);
+ if (ret)
+ goto err;
+ }
+ gdp = ext4_get_group_desc(sb, i, NULL);
+ ret = add_system_zone(system_blks,
+ ext4_block_bitmap(sb, gdp), 1, 0);
+ if (ret)
+ goto err;
+ ret = add_system_zone(system_blks,
+ ext4_inode_bitmap(sb, gdp), 1, 0);
+ if (ret)
+ goto err;
+ ret = add_system_zone(system_blks,
+ ext4_inode_table(sb, gdp),
+ sbi->s_itb_per_group, 0);
+ if (ret)
+ goto err;
+ }
+ if (ext4_has_feature_journal(sb) && sbi->s_es->s_journal_inum) {
+ ret = ext4_protect_reserved_inode(sb, system_blks,
+ le32_to_cpu(sbi->s_es->s_journal_inum));
+ if (ret)
+ goto err;
+ }
+
+ /*
+ * System blks rbtree complete, announce it once to prevent racing
+ * with ext4_inode_block_valid() accessing the rbtree at the same
+ * time.
+ */
+ rcu_assign_pointer(sbi->s_system_blks, system_blks);
+
+ if (test_opt(sb, DEBUG))
+ debug_print_tree(sbi);
+ return 0;
+err:
+ release_system_zone(system_blks);
+ kfree(system_blks);
+ return ret;
+}
+
+/*
+ * Called when the filesystem is unmounted or when remounting it with
+ * noblock_validity specified.
+ *
+ * The update of system_blks pointer in this function is protected by
+ * sb->s_umount semaphore. However we have to be careful as we can be
+ * racing with ext4_inode_block_valid() calls reading system_blks rbtree
+ * protected only by RCU. So we first clear the system_blks pointer and
+ * then free the rbtree only after RCU grace period expires.
+ */
+void ext4_release_system_zone(struct super_block *sb)
+{
+ struct ext4_system_blocks *system_blks;
+
+ system_blks = rcu_dereference_protected(EXT4_SB(sb)->s_system_blks,
+ lockdep_is_held(&sb->s_umount));
+ rcu_assign_pointer(EXT4_SB(sb)->s_system_blks, NULL);
+
+ if (system_blks)
+ call_rcu(&system_blks->rcu, ext4_destroy_system_zone);
+}
+
+int ext4_sb_block_valid(struct super_block *sb, struct inode *inode,
+ ext4_fsblk_t start_blk, unsigned int count)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_system_blocks *system_blks;
+ struct ext4_system_zone *entry;
+ struct rb_node *n;
+ int ret = 1;
+
+ if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
+ (start_blk + count < start_blk) ||
+ (start_blk + count > ext4_blocks_count(sbi->s_es)))
+ return 0;
+
+ /*
+ * Lock the system zone to prevent it being released concurrently
+ * when doing a remount which inverse current "[no]block_validity"
+ * mount option.
+ */
+ rcu_read_lock();
+ system_blks = rcu_dereference(sbi->s_system_blks);
+ if (system_blks == NULL)
+ goto out_rcu;
+
+ n = system_blks->root.rb_node;
+ while (n) {
+ entry = rb_entry(n, struct ext4_system_zone, node);
+ if (start_blk + count - 1 < entry->start_blk)
+ n = n->rb_left;
+ else if (start_blk >= (entry->start_blk + entry->count))
+ n = n->rb_right;
+ else {
+ ret = 0;
+ if (inode)
+ ret = (entry->ino == inode->i_ino);
+ break;
+ }
+ }
+out_rcu:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Returns 1 if the passed-in block region (start_blk,
+ * start_blk+count) is valid; 0 if some part of the block region
+ * overlaps with some other filesystem metadata blocks.
+ */
+int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
+ unsigned int count)
+{
+ return ext4_sb_block_valid(inode->i_sb, inode, start_blk, count);
+}
+
+int ext4_check_blockref(const char *function, unsigned int line,
+ struct inode *inode, __le32 *p, unsigned int max)
+{
+ __le32 *bref = p;
+ unsigned int blk;
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal && inode == journal->j_inode)
+ return 0;
+
+ while (bref < p+max) {
+ blk = le32_to_cpu(*bref++);
+ if (blk &&
+ unlikely(!ext4_inode_block_valid(inode, blk, 1))) {
+ ext4_error_inode(inode, function, line, blk,
+ "invalid block");
+ return -EFSCORRUPTED;
+ }
+ }
+ return 0;
+}
+