diff options
Diffstat (limited to 'fs/hpfs/buffer.c')
| -rw-r--r-- | fs/hpfs/buffer.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c new file mode 100644 index 0000000..2807aa8 --- /dev/null +++ b/fs/hpfs/buffer.c @@ -0,0 +1,175 @@ +/* + * linux/fs/hpfs/buffer.c + * + * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 + * + * general buffer i/o + */ + +#include "hpfs_fn.h" + +void hpfs_lock_creation(struct super_block *s) +{ +#ifdef DEBUG_LOCKS + printk("lock creation\n"); +#endif + down(&hpfs_sb(s)->hpfs_creation_de); +} + +void hpfs_unlock_creation(struct super_block *s) +{ +#ifdef DEBUG_LOCKS + printk("unlock creation\n"); +#endif + up(&hpfs_sb(s)->hpfs_creation_de); +} + +/* Map a sector into a buffer and return pointers to it and to the buffer. */ + +void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp, + int ahead) +{ + struct buffer_head *bh; + + cond_resched(); + + *bhp = bh = sb_bread(s, secno); + if (bh != NULL) + return bh->b_data; + else { + printk("HPFS: hpfs_map_sector: read error\n"); + return NULL; + } +} + +/* Like hpfs_map_sector but don't read anything */ + +void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp) +{ + struct buffer_head *bh; + /*return hpfs_map_sector(s, secno, bhp, 0);*/ + + cond_resched(); + + if ((*bhp = bh = sb_getblk(s, secno)) != NULL) { + if (!buffer_uptodate(bh)) wait_on_buffer(bh); + set_buffer_uptodate(bh); + return bh->b_data; + } else { + printk("HPFS: hpfs_get_sector: getblk failed\n"); + return NULL; + } +} + +/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */ + +void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh, + int ahead) +{ + struct buffer_head *bh; + char *data; + + cond_resched(); + + if (secno & 3) { + printk("HPFS: hpfs_map_4sectors: unaligned read\n"); + return NULL; + } + + qbh->data = data = (char *)kmalloc(2048, GFP_NOFS); + if (!data) { + printk("HPFS: hpfs_map_4sectors: out of memory\n"); + goto bail; + } + + qbh->bh[0] = bh = sb_bread(s, secno); + if (!bh) + goto bail0; + memcpy(data, bh->b_data, 512); + + qbh->bh[1] = bh = sb_bread(s, secno + 1); + if (!bh) + goto bail1; + memcpy(data + 512, bh->b_data, 512); + + qbh->bh[2] = bh = sb_bread(s, secno + 2); + if (!bh) + goto bail2; + memcpy(data + 2 * 512, bh->b_data, 512); + + qbh->bh[3] = bh = sb_bread(s, secno + 3); + if (!bh) + goto bail3; + memcpy(data + 3 * 512, bh->b_data, 512); + + return data; + + bail3: + brelse(qbh->bh[2]); + bail2: + brelse(qbh->bh[1]); + bail1: + brelse(qbh->bh[0]); + bail0: + kfree(data); + printk("HPFS: hpfs_map_4sectors: read error\n"); + bail: + return NULL; +} + +/* Don't read sectors */ + +void *hpfs_get_4sectors(struct super_block *s, unsigned secno, + struct quad_buffer_head *qbh) +{ + cond_resched(); + + if (secno & 3) { + printk("HPFS: hpfs_get_4sectors: unaligned read\n"); + return NULL; + } + + /*return hpfs_map_4sectors(s, secno, qbh, 0);*/ + if (!(qbh->data = kmalloc(2048, GFP_NOFS))) { + printk("HPFS: hpfs_get_4sectors: out of memory\n"); + return NULL; + } + if (!(hpfs_get_sector(s, secno, &qbh->bh[0]))) goto bail0; + if (!(hpfs_get_sector(s, secno + 1, &qbh->bh[1]))) goto bail1; + if (!(hpfs_get_sector(s, secno + 2, &qbh->bh[2]))) goto bail2; + if (!(hpfs_get_sector(s, secno + 3, &qbh->bh[3]))) goto bail3; + memcpy(qbh->data, qbh->bh[0]->b_data, 512); + memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512); + memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512); + memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512); + return qbh->data; + + bail3: brelse(qbh->bh[2]); + bail2: brelse(qbh->bh[1]); + bail1: brelse(qbh->bh[0]); + bail0: + return NULL; +} + + +void hpfs_brelse4(struct quad_buffer_head *qbh) +{ + brelse(qbh->bh[3]); + brelse(qbh->bh[2]); + brelse(qbh->bh[1]); + brelse(qbh->bh[0]); + kfree(qbh->data); +} + +void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh) +{ + PRINTK(("hpfs_mark_4buffers_dirty\n")); + memcpy(qbh->bh[0]->b_data, qbh->data, 512); + memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512); + memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512); + memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512); + mark_buffer_dirty(qbh->bh[0]); + mark_buffer_dirty(qbh->bh[1]); + mark_buffer_dirty(qbh->bh[2]); + mark_buffer_dirty(qbh->bh[3]); +} |
