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-rw-r--r--fs/hpfs/buffer.c96
1 files changed, 50 insertions, 46 deletions
diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
index 4d0a1af..139ef16 100644
--- a/fs/hpfs/buffer.c
+++ b/fs/hpfs/buffer.c
@@ -86,7 +86,6 @@ void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head
void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
int ahead)
{
- struct buffer_head *bh;
char *data;
hpfs_lock_assert(s);
@@ -100,34 +99,32 @@ void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffe
hpfs_prefetch_sectors(s, secno, 4 + ahead);
+ if (!(qbh->bh[0] = sb_bread(s, secno + 0))) goto bail0;
+ if (!(qbh->bh[1] = sb_bread(s, secno + 1))) goto bail1;
+ if (!(qbh->bh[2] = sb_bread(s, secno + 2))) goto bail2;
+ if (!(qbh->bh[3] = sb_bread(s, secno + 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;
+ }
+
qbh->data = data = kmalloc(2048, GFP_NOFS);
if (!data) {
printk("HPFS: hpfs_map_4sectors: out of memory\n");
- goto bail;
+ goto bail4;
}
- 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);
+ 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:
@@ -135,9 +132,6 @@ void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffe
bail1:
brelse(qbh->bh[0]);
bail0:
- kfree(data);
- printk("HPFS: hpfs_map_4sectors: read error\n");
- bail:
return NULL;
}
@@ -155,44 +149,54 @@ void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
return NULL;
}
- /*return hpfs_map_4sectors(s, secno, qbh, 0);*/
+ 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))) {
printk("HPFS: hpfs_get_4sectors: out of memory\n");
- return NULL;
+ goto bail4;
}
- 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:
+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)
{
- brelse(qbh->bh[3]);
- brelse(qbh->bh[2]);
- brelse(qbh->bh[1]);
+ if (unlikely(qbh->data != qbh->bh[0]->b_data))
+ kfree(qbh->data);
brelse(qbh->bh[0]);
- kfree(qbh->data);
+ brelse(qbh->bh[1]);
+ brelse(qbh->bh[2]);
+ brelse(qbh->bh[3]);
}
void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
{
- 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);
+ 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]);
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