diff options
Diffstat (limited to 'fs/minix')
| -rw-r--r-- | fs/minix/bitmap.c | 55 | ||||
| -rw-r--r-- | fs/minix/inode.c | 25 | ||||
| -rw-r--r-- | fs/minix/minix.h | 11 |
3 files changed, 55 insertions, 36 deletions
diff --git a/fs/minix/bitmap.c b/fs/minix/bitmap.c index 3f32bcb0d9b..ef175cb8cfd 100644 --- a/fs/minix/bitmap.c +++ b/fs/minix/bitmap.c @@ -16,38 +16,26 @@ #include <linux/bitops.h> #include <linux/sched.h> -static const int nibblemap[] = { 4,3,3,2,3,2,2,1,3,2,2,1,2,1,1,0 }; - static DEFINE_SPINLOCK(bitmap_lock); -static unsigned long count_free(struct buffer_head *map[], unsigned numblocks, __u32 numbits) +/* + * 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) { - unsigned i, j, sum = 0; - struct buffer_head *bh; - - for (i=0; i<numblocks-1; i++) { - if (!(bh=map[i])) - return(0); - for (j=0; j<bh->b_size; j++) - sum += nibblemap[bh->b_data[j] & 0xf] - + nibblemap[(bh->b_data[j]>>4) & 0xf]; - } + __u32 sum = 0; + unsigned blocks = DIV_ROUND_UP(numbits, blocksize * 8); - if (numblocks==0 || !(bh=map[numblocks-1])) - return(0); - i = ((numbits - (numblocks-1) * bh->b_size * 8) / 16) * 2; - for (j=0; j<i; j++) { - sum += nibblemap[bh->b_data[j] & 0xf] - + nibblemap[(bh->b_data[j]>>4) & 0xf]; + while (blocks--) { + unsigned words = blocksize / 2; + __u16 *p = (__u16 *)(*map++)->b_data; + while (words--) + sum += 16 - hweight16(*p++); } - i = numbits%16; - if (i!=0) { - i = *(__u16 *)(&bh->b_data[j]) | ~((1<<i) - 1); - sum += nibblemap[i & 0xf] + nibblemap[(i>>4) & 0xf]; - sum += nibblemap[(i>>8) & 0xf] + nibblemap[(i>>12) & 0xf]; - } - return(sum); + return sum; } void minix_free_block(struct inode *inode, unsigned long block) @@ -105,10 +93,12 @@ int minix_new_block(struct inode * inode) return 0; } -unsigned long minix_count_free_blocks(struct minix_sb_info *sbi) +unsigned long minix_count_free_blocks(struct super_block *sb) { - return (count_free(sbi->s_zmap, sbi->s_zmap_blocks, - sbi->s_nzones - sbi->s_firstdatazone + 1) + 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); } @@ -273,7 +263,10 @@ struct inode *minix_new_inode(const struct inode *dir, int mode, int *error) return inode; } -unsigned long minix_count_free_inodes(struct minix_sb_info *sbi) +unsigned long minix_count_free_inodes(struct super_block *sb) { - return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1); + struct minix_sb_info *sbi = minix_sb(sb); + u32 bits = sbi->s_ninodes + 1; + + return count_free(sbi->s_imap, sb->s_blocksize, bits); } diff --git a/fs/minix/inode.c b/fs/minix/inode.c index 64cdcd662ff..1d9e33966db 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -279,6 +279,27 @@ static int minix_fill_super(struct super_block *s, void *data, int silent) else if (sbi->s_mount_state & MINIX_ERROR_FS) printk("MINIX-fs: mounting file system with errors, " "running fsck is recommended\n"); + + /* Apparently minix can create filesystems that allocate more blocks for + * the bitmaps than needed. We simply ignore that, but verify it didn't + * create one with not enough blocks and bail out if so. + */ + block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize); + if (sbi->s_imap_blocks < block) { + printk("MINIX-fs: file system does not have enough " + "imap blocks allocated. Refusing to mount\n"); + goto out_iput; + } + + block = minix_blocks_needed( + (sbi->s_nzones - (sbi->s_firstdatazone + 1)), + s->s_blocksize); + if (sbi->s_zmap_blocks < block) { + printk("MINIX-fs: file system does not have enough " + "zmap blocks allocated. Refusing to mount.\n"); + goto out_iput; + } + return 0; out_iput: @@ -339,10 +360,10 @@ static int minix_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_type = sb->s_magic; buf->f_bsize = sb->s_blocksize; buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size; - buf->f_bfree = minix_count_free_blocks(sbi); + buf->f_bfree = minix_count_free_blocks(sb); buf->f_bavail = buf->f_bfree; buf->f_files = sbi->s_ninodes; - buf->f_ffree = minix_count_free_inodes(sbi); + buf->f_ffree = minix_count_free_inodes(sb); buf->f_namelen = sbi->s_namelen; buf->f_fsid.val[0] = (u32)id; buf->f_fsid.val[1] = (u32)(id >> 32); diff --git a/fs/minix/minix.h b/fs/minix/minix.h index 341e2122879..26bbd55e82e 100644 --- a/fs/minix/minix.h +++ b/fs/minix/minix.h @@ -48,10 +48,10 @@ extern struct minix_inode * minix_V1_raw_inode(struct super_block *, ino_t, stru extern struct minix2_inode * minix_V2_raw_inode(struct super_block *, ino_t, struct buffer_head **); extern struct inode * minix_new_inode(const struct inode *, int, int *); extern void minix_free_inode(struct inode * inode); -extern unsigned long minix_count_free_inodes(struct minix_sb_info *sbi); +extern unsigned long minix_count_free_inodes(struct super_block *sb); extern int minix_new_block(struct inode * inode); extern void minix_free_block(struct inode *inode, unsigned long block); -extern unsigned long minix_count_free_blocks(struct minix_sb_info *sbi); +extern unsigned long minix_count_free_blocks(struct super_block *sb); extern int minix_getattr(struct vfsmount *, struct dentry *, struct kstat *); extern int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len); @@ -88,6 +88,11 @@ static inline struct minix_inode_info *minix_i(struct inode *inode) return list_entry(inode, struct minix_inode_info, vfs_inode); } +static inline unsigned minix_blocks_needed(unsigned bits, unsigned blocksize) +{ + return DIV_ROUND_UP(bits, blocksize * 8); +} + #if defined(CONFIG_MINIX_FS_NATIVE_ENDIAN) && \ defined(CONFIG_MINIX_FS_BIG_ENDIAN_16BIT_INDEXED) @@ -125,7 +130,7 @@ static inline int minix_find_first_zero_bit(const void *vaddr, unsigned size) if (!size) return 0; - size = (size >> 4) + ((size & 15) > 0); + size >>= 4; while (*p++ == 0xffff) { if (--size == 0) return (p - addr) << 4; |