/* * 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, int *error) { 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) { *error = -ENOMEM; return NULL; } j = bits_per_zone; bh = NULL; *error = -ENOSPC; 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 NULL; } 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 NULL; } spin_unlock(&bitmap_lock); mark_buffer_dirty(bh); j += i * bits_per_zone; if (!j || j > sbi->s_ninodes) { iput(inode); return NULL; } inode_init_owner(inode, dir, mode); inode->i_ino = j; inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); inode->i_blocks = 0; memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u)); insert_inode_hash(inode); mark_inode_dirty(inode); *error = 0; 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); } m userspace will result in a SIGBUS being sent to the user process. The MEM errors form userspace will result in a SIGKILL and also cause the offending pages to be claimed so they are no longer used in future tasks. SIGKILL is used to ensure that the process does not try to coredump and result in an attempt to read the memory again from within kernel space. Although there is a HV call to scrub the memory (mem_scrub), there is no easy way to guarantee that the real memory address(es) are not used by other tasks. Clearing the error with mem_scrub would zero the memory and cause the other processes to proceed with bad data. The handling of other non-resumable errors remain unchanged and will cause a panic. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/scsi/scsi_tcq.h')