From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- fs/minix/bitmap.c | 269 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 269 insertions(+) create mode 100644 fs/minix/bitmap.c (limited to 'fs/minix/bitmap.c') diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c new file mode 100644 index 000000000..abec43833 --- /dev/null +++ b/fs/minix/bitmap.c @@ -0,0 +1,269 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/minix/bitmap.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +/* + * Modified for 680x0 by Hamish Macdonald + * Fixed for 680x0 by Andreas Schwab + */ + +/* bitmap.c contains the code that handles the inode and block bitmaps */ + +#include "minix.h" +#include +#include +#include + +static DEFINE_SPINLOCK(bitmap_lock); + +/* + * bitmap consists of blocks filled with 16bit words + * bit set == busy, bit clear == free + * endianness is a mess, but for counting zero bits it really doesn't matter... + */ +static __u32 count_free(struct buffer_head *map[], unsigned blocksize, __u32 numbits) +{ + __u32 sum = 0; + unsigned blocks = DIV_ROUND_UP(numbits, blocksize * 8); + + while (blocks--) { + unsigned words = blocksize / 2; + __u16 *p = (__u16 *)(*map++)->b_data; + while (words--) + sum += 16 - hweight16(*p++); + } + + return sum; +} + +void minix_free_block(struct inode *inode, unsigned long block) +{ + struct super_block *sb = inode->i_sb; + struct minix_sb_info *sbi = minix_sb(sb); + struct buffer_head *bh; + int k = sb->s_blocksize_bits + 3; + unsigned long bit, zone; + + if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) { + printk("Trying to free block not in datazone\n"); + return; + } + zone = block - sbi->s_firstdatazone + 1; + bit = zone & ((1<>= k; + if (zone >= sbi->s_zmap_blocks) { + printk("minix_free_block: nonexistent bitmap buffer\n"); + return; + } + bh = sbi->s_zmap[zone]; + spin_lock(&bitmap_lock); + if (!minix_test_and_clear_bit(bit, bh->b_data)) + printk("minix_free_block (%s:%lu): bit already cleared\n", + sb->s_id, block); + spin_unlock(&bitmap_lock); + mark_buffer_dirty(bh); + return; +} + +int minix_new_block(struct inode * inode) +{ + struct minix_sb_info *sbi = minix_sb(inode->i_sb); + int bits_per_zone = 8 * inode->i_sb->s_blocksize; + int i; + + for (i = 0; i < sbi->s_zmap_blocks; i++) { + struct buffer_head *bh = sbi->s_zmap[i]; + int j; + + spin_lock(&bitmap_lock); + j = minix_find_first_zero_bit(bh->b_data, bits_per_zone); + if (j < bits_per_zone) { + minix_set_bit(j, bh->b_data); + spin_unlock(&bitmap_lock); + mark_buffer_dirty(bh); + j += i * bits_per_zone + sbi->s_firstdatazone-1; + if (j < sbi->s_firstdatazone || j >= sbi->s_nzones) + break; + return j; + } + spin_unlock(&bitmap_lock); + } + return 0; +} + +unsigned long minix_count_free_blocks(struct super_block *sb) +{ + struct minix_sb_info *sbi = minix_sb(sb); + u32 bits = sbi->s_nzones - sbi->s_firstdatazone + 1; + + return (count_free(sbi->s_zmap, sb->s_blocksize, bits) + << sbi->s_log_zone_size); +} + +struct minix_inode * +minix_V1_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh) +{ + int block; + struct minix_sb_info *sbi = minix_sb(sb); + struct minix_inode *p; + + if (!ino || ino > sbi->s_ninodes) { + printk("Bad inode number on dev %s: %ld is out of range\n", + sb->s_id, (long)ino); + return NULL; + } + ino--; + block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks + + ino / MINIX_INODES_PER_BLOCK; + *bh = sb_bread(sb, block); + if (!*bh) { + printk("Unable to read inode block\n"); + return NULL; + } + p = (void *)(*bh)->b_data; + return p + ino % MINIX_INODES_PER_BLOCK; +} + +struct minix2_inode * +minix_V2_raw_inode(struct super_block *sb, ino_t ino, struct buffer_head **bh) +{ + int block; + struct minix_sb_info *sbi = minix_sb(sb); + struct minix2_inode *p; + int minix2_inodes_per_block = sb->s_blocksize / sizeof(struct minix2_inode); + + *bh = NULL; + if (!ino || ino > sbi->s_ninodes) { + printk("Bad inode number on dev %s: %ld is out of range\n", + sb->s_id, (long)ino); + return NULL; + } + ino--; + block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks + + ino / minix2_inodes_per_block; + *bh = sb_bread(sb, block); + if (!*bh) { + printk("Unable to read inode block\n"); + return NULL; + } + p = (void *)(*bh)->b_data; + return p + ino % minix2_inodes_per_block; +} + +/* Clear the link count and mode of a deleted inode on disk. */ + +static void minix_clear_inode(struct inode *inode) +{ + struct buffer_head *bh = NULL; + + if (INODE_VERSION(inode) == MINIX_V1) { + struct minix_inode *raw_inode; + raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh); + if (raw_inode) { + raw_inode->i_nlinks = 0; + raw_inode->i_mode = 0; + } + } else { + struct minix2_inode *raw_inode; + raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh); + if (raw_inode) { + raw_inode->i_nlinks = 0; + raw_inode->i_mode = 0; + } + } + if (bh) { + mark_buffer_dirty(bh); + brelse (bh); + } +} + +void minix_free_inode(struct inode * inode) +{ + struct super_block *sb = inode->i_sb; + struct minix_sb_info *sbi = minix_sb(inode->i_sb); + struct buffer_head *bh; + int k = sb->s_blocksize_bits + 3; + unsigned long ino, bit; + + ino = inode->i_ino; + if (ino < 1 || ino > sbi->s_ninodes) { + printk("minix_free_inode: inode 0 or nonexistent inode\n"); + return; + } + bit = ino & ((1<>= k; + if (ino >= sbi->s_imap_blocks) { + printk("minix_free_inode: nonexistent imap in superblock\n"); + return; + } + + minix_clear_inode(inode); /* clear on-disk copy */ + + bh = sbi->s_imap[ino]; + spin_lock(&bitmap_lock); + if (!minix_test_and_clear_bit(bit, bh->b_data)) + printk("minix_free_inode: bit %lu already cleared\n", bit); + spin_unlock(&bitmap_lock); + mark_buffer_dirty(bh); +} + +struct inode *minix_new_inode(const struct inode *dir, umode_t mode) +{ + struct super_block *sb = dir->i_sb; + struct minix_sb_info *sbi = minix_sb(sb); + struct inode *inode = new_inode(sb); + struct buffer_head * bh; + int bits_per_zone = 8 * sb->s_blocksize; + unsigned long j; + int i; + + if (!inode) + return ERR_PTR(-ENOMEM); + j = bits_per_zone; + bh = NULL; + spin_lock(&bitmap_lock); + for (i = 0; i < sbi->s_imap_blocks; i++) { + bh = sbi->s_imap[i]; + j = minix_find_first_zero_bit(bh->b_data, bits_per_zone); + if (j < bits_per_zone) + break; + } + if (!bh || j >= bits_per_zone) { + spin_unlock(&bitmap_lock); + iput(inode); + return ERR_PTR(-ENOSPC); + } + if (minix_test_and_set_bit(j, bh->b_data)) { /* shouldn't happen */ + spin_unlock(&bitmap_lock); + printk("minix_new_inode: bit already set\n"); + iput(inode); + return ERR_PTR(-ENOSPC); + } + spin_unlock(&bitmap_lock); + mark_buffer_dirty(bh); + j += i * bits_per_zone; + if (!j || j > sbi->s_ninodes) { + iput(inode); + return ERR_PTR(-EFSCORRUPTED); + } + inode_init_owner(&nop_mnt_idmap, inode, dir, mode); + inode->i_ino = j; + simple_inode_init_ts(inode); + inode->i_blocks = 0; + memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u)); + insert_inode_hash(inode); + mark_inode_dirty(inode); + + return inode; +} + +unsigned long minix_count_free_inodes(struct super_block *sb) +{ + struct minix_sb_info *sbi = minix_sb(sb); + u32 bits = sbi->s_ninodes + 1; + + return count_free(sbi->s_imap, sb->s_blocksize, bits); +} -- cgit v1.3.1