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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233// SPDX-License-Identifier: GPL-2.0/* * linux/fs/hpfs/buffer.c * * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 * * general buffer i/o */#include <linux/sched.h>#include <linux/slab.h>#include <linux/blkdev.h>#include "hpfs_fn.h"
secno hpfs_search_hotfix_map(struct super_block *s, secno sec){ unsigned i; struct hpfs_sb_info *sbi = hpfs_sb(s); for (i = 0; unlikely(i < sbi->n_hotfixes); i++) { if (sbi->hotfix_from[i] == sec) { return sbi->hotfix_to[i]; } } return sec;}
unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n){ unsigned i; struct hpfs_sb_info *sbi = hpfs_sb(s); for (i = 0; unlikely(i < sbi->n_hotfixes); i++) { if (sbi->hotfix_from[i] >= sec && sbi->hotfix_from[i] < sec + n) { n = sbi->hotfix_from[i] - sec; } } return n;}
void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n){ struct buffer_head *bh; struct blk_plug plug;
if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size)) return;
if (unlikely(hpfs_search_hotfix_map_for_range(s, secno, n) != n)) return;
bh = sb_find_get_block(s, secno); if (bh) { if (buffer_uptodate(bh)) { brelse(bh); return; } brelse(bh); }
blk_start_plug(&plug); while (n > 0) { if (unlikely(secno >= hpfs_sb(s)->sb_fs_size)) break; sb_breadahead(s, secno); secno++; n--; } blk_finish_plug(&plug);}
/* 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;
hpfs_lock_assert(s);
hpfs_prefetch_sectors(s, secno, ahead);
cond_resched();
*bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno)); if (bh != NULL) return bh->b_data; else { pr_err("%s(): read error\n", __func__); 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);*/
hpfs_lock_assert(s);
cond_resched();
if ((*bhp = bh = sb_getblk(s, hpfs_search_hotfix_map(s, secno))) != NULL) { if (!buffer_uptodate(bh)) wait_on_buffer(bh); set_buffer_uptodate(bh); return bh->b_data; } else { pr_err("%s(): getblk failed\n", __func__); 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){ char *data;
hpfs_lock_assert(s);
cond_resched();
if (secno & 3) { pr_err("%s(): unaligned read\n", __func__); return NULL; }
hpfs_prefetch_sectors(s, secno, 4 + ahead);
if (!hpfs_map_sector(s, secno + 0, &qbh->bh[0], 0)) goto bail0; if (!hpfs_map_sector(s, secno + 1, &qbh->bh[1], 0)) goto bail1; if (!hpfs_map_sector(s, secno + 2, &qbh->bh[2], 0)) goto bail2; if (!hpfs_map_sector(s, secno + 3, &qbh->bh[3], 0)) goto bail3;
if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) && likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) && likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) { return qbh->data = qbh->bh[0]->b_data; }
qbh->data = data = kmalloc(2048, GFP_NOFS); if (!data) { pr_err("%s(): out of memory\n", __func__); goto bail4; }
memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512); memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512); memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512); memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
return data;
bail4: brelse(qbh->bh[3]); bail3: brelse(qbh->bh[2]); bail2: brelse(qbh->bh[1]); bail1: brelse(qbh->bh[0]); bail0: return NULL;}
/* Don't read sectors */
void *hpfs_get_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh){ cond_resched();
hpfs_lock_assert(s);
if (secno & 3) { pr_err("%s(): unaligned read\n", __func__); return NULL; }
if (!hpfs_get_sector(s, secno + 0, &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;
if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) && likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) && likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) { return qbh->data = qbh->bh[0]->b_data; }
if (!(qbh->data = kmalloc(2048, GFP_NOFS))) { pr_err("%s(): out of memory\n", __func__); goto bail4; } return qbh->data;
bail4: brelse(qbh->bh[3]);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){ if (unlikely(qbh->data != qbh->bh[0]->b_data)) kfree(qbh->data); brelse(qbh->bh[0]); brelse(qbh->bh[1]); brelse(qbh->bh[2]); brelse(qbh->bh[3]);}
void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh){ if (unlikely(qbh->data != qbh->bh[0]->b_data)) { memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512); memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 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]);}