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yaml
---
r: 91834
b: refs/heads/master
c: 423cf6d
h: refs/heads/master
v: v3
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Jan Kara committed Apr 17, 2008
1 parent 3e9b962 commit 169f751
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Showing 3 changed files with 100 additions and 143 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 38b74a53e5625b7bbbd08918294b86f1db2f0565
refs/heads/master: 423cf6dc04eb79d441bfda2b127bc4b57134b41d
239 changes: 98 additions & 141 deletions trunk/fs/udf/super.c
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Original file line number Diff line number Diff line change
Expand Up @@ -678,149 +678,120 @@ static int udf_vrs(struct super_block *sb, int silent)
}

/*
* udf_find_anchor
*
* PURPOSE
* Find an anchor volume descriptor.
*
* PRE-CONDITIONS
* sb Pointer to _locked_ superblock.
* lastblock Last block on media.
*
* POST-CONDITIONS
* <return> 1 if not found, 0 if ok
*
* HISTORY
* July 1, 1997 - Andrew E. Mileski
* Written, tested, and released.
* Check whether there is an anchor block in the given block
*/
static void udf_find_anchor(struct super_block *sb)
static int udf_check_anchor_block(struct super_block *sb, sector_t block,
bool varconv)
{
int lastblock;
struct buffer_head *bh = NULL;
tag *t;
uint16_t ident;
uint32_t location;

if (varconv)
bh = sb_bread(sb, udf_fixed_to_variable(block));
else
bh = sb_bread(sb, block);

if (!bh)
return 0;

t = (tag *)bh->b_data;
ident = le16_to_cpu(t->tagIdent);
location = le32_to_cpu(t->tagLocation);
brelse(bh);
if (ident != TAG_IDENT_AVDP)
return 0;
return location == block;
}

/* Search for an anchor volume descriptor pointer */
static sector_t udf_scan_anchors(struct super_block *sb, bool varconv,
sector_t lastblock)
{
sector_t last[4];
int i;
struct udf_sb_info *sbi;
struct udf_sb_info *sbi = UDF_SB(sb);

sbi = UDF_SB(sb);
lastblock = sbi->s_last_block;
last[0] = lastblock;
last[1] = last[0] - 2;
last[2] = last[0] - 150;
last[3] = last[0] - 152;

if (lastblock) {
int varlastblock = udf_variable_to_fixed(lastblock);
int last[] = { lastblock, lastblock - 2,
lastblock - 150, lastblock - 152,
varlastblock, varlastblock - 2,
varlastblock - 150, varlastblock - 152 };

lastblock = 0;

/* Search for an anchor volume descriptor pointer */

/* according to spec, anchor is in either:
* block 256
* lastblock-256
* lastblock
* however, if the disc isn't closed, it could be 512 */

for (i = 0; !lastblock && i < ARRAY_SIZE(last); i++) {
ident = location = 0;
if (last[i] >= 0) {
bh = sb_bread(sb, last[i]);
if (bh) {
tag *t = (tag *)bh->b_data;
ident = le16_to_cpu(t->tagIdent);
location = le32_to_cpu(t->tagLocation);
brelse(bh);
}
}
/* according to spec, anchor is in either:
* block 256
* lastblock-256
* lastblock
* however, if the disc isn't closed, it could be 512 */

if (ident == TAG_IDENT_AVDP) {
if (location == last[i] - sbi->s_session) {
lastblock = last[i] - sbi->s_session;
sbi->s_anchor[0] = lastblock;
sbi->s_anchor[1] = lastblock - 256;
} else if (location ==
udf_variable_to_fixed(last[i]) -
sbi->s_session) {
UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
lastblock =
udf_variable_to_fixed(last[i]) -
sbi->s_session;
sbi->s_anchor[0] = lastblock;
sbi->s_anchor[1] = lastblock - 256 -
sbi->s_session;
} else {
udf_debug("Anchor found at block %d, "
"location mismatch %d.\n",
last[i], location);
}
} else if (ident == TAG_IDENT_FE ||
ident == TAG_IDENT_EFE) {
lastblock = last[i];
sbi->s_anchor[3] = 512;
} else {
ident = location = 0;
if (last[i] >= 256) {
bh = sb_bread(sb, last[i] - 256);
if (bh) {
tag *t = (tag *)bh->b_data;
ident = le16_to_cpu(
t->tagIdent);
location = le32_to_cpu(
t->tagLocation);
brelse(bh);
}
}
for (i = 0; i < ARRAY_SIZE(last); i++) {
if (last[i] < 0)
continue;

if (ident == TAG_IDENT_AVDP &&
location == last[i] - 256 -
sbi->s_session) {
lastblock = last[i];
sbi->s_anchor[1] = last[i] - 256;
} else {
ident = location = 0;
if (last[i] >= 312 + sbi->s_session) {
bh = sb_bread(sb,
last[i] - 312 -
sbi->s_session);
if (bh) {
tag *t = (tag *)
bh->b_data;
ident = le16_to_cpu(
t->tagIdent);
location = le32_to_cpu(
t->tagLocation);
brelse(bh);
}
}
if (udf_check_anchor_block(sb, last[i], varconv)) {
sbi->s_anchor[0] = last[i];
sbi->s_anchor[1] = last[i] - 256;
return last[i];
}

if (ident == TAG_IDENT_AVDP &&
location == udf_variable_to_fixed(last[i]) - 256) {
UDF_SET_FLAG(sb,
UDF_FLAG_VARCONV);
lastblock = udf_variable_to_fixed(last[i]);
sbi->s_anchor[1] = lastblock - 256;
}
}
}
if (last[i] < 256)
continue;

if (udf_check_anchor_block(sb, last[i] - 256, varconv)) {
sbi->s_anchor[1] = last[i] - 256;
return last[i];
}
}

if (!lastblock) {
/* We haven't found the lastblock. check 312 */
bh = sb_bread(sb, 312 + sbi->s_session);
if (bh) {
tag *t = (tag *)bh->b_data;
ident = le16_to_cpu(t->tagIdent);
location = le32_to_cpu(t->tagLocation);
brelse(bh);
if (udf_check_anchor_block(sb, sbi->s_session + 256, varconv)) {
sbi->s_anchor[0] = sbi->s_session + 256;
return last[0];
}
if (udf_check_anchor_block(sb, sbi->s_session + 512, varconv)) {
sbi->s_anchor[0] = sbi->s_session + 512;
return last[0];
}
return 0;
}

if (ident == TAG_IDENT_AVDP && location == 256)
UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
}
/*
* Find an anchor volume descriptor. The function expects sbi->s_lastblock to
* be the last block on the media.
*
* Return 1 if not found, 0 if ok
*
*/
static void udf_find_anchor(struct super_block *sb)
{
sector_t lastblock;
struct buffer_head *bh = NULL;
uint16_t ident;
int i;
struct udf_sb_info *sbi = UDF_SB(sb);

lastblock = udf_scan_anchors(sb, 0, sbi->s_last_block);
if (lastblock)
goto check_anchor;

/* No anchor found? Try VARCONV conversion of block numbers */
/* Firstly, we try to not convert number of the last block */
lastblock = udf_scan_anchors(sb, 1,
udf_variable_to_fixed(sbi->s_last_block));
if (lastblock) {
UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
goto check_anchor;
}

/* Secondly, we try with converted number of the last block */
lastblock = udf_scan_anchors(sb, 1, sbi->s_last_block);
if (lastblock)
UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);

check_anchor:
/*
* Check located anchors and the anchor block supplied via
* mount options
*/
for (i = 0; i < ARRAY_SIZE(sbi->s_anchor); i++) {
if (!sbi->s_anchor[i])
continue;
Expand All @@ -830,9 +801,7 @@ static void udf_find_anchor(struct super_block *sb)
sbi->s_anchor[i] = 0;
else {
brelse(bh);
if ((ident != TAG_IDENT_AVDP) &&
(i || (ident != TAG_IDENT_FE &&
ident != TAG_IDENT_EFE)))
if (ident != TAG_IDENT_AVDP)
sbi->s_anchor[i] = 0;
}
}
Expand Down Expand Up @@ -1225,17 +1194,6 @@ static int udf_load_partdesc(struct super_block *sb, sector_t block)
if (ret)
goto out_bh;

if (!sbi->s_last_block) {
sbi->s_last_block = udf_get_last_block(sb);
udf_find_anchor(sb);
if (!sbi->s_last_block) {
udf_debug("Unable to determine Lastblock (For "
"Virtual Partition)\n");
ret = 1;
goto out_bh;
}
}

ret = udf_load_vat(sb, i, type1_idx);
out_bh:
/* In case loading failed, we handle cleanup in udf_fill_super */
Expand Down Expand Up @@ -1778,7 +1736,6 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
sbi->s_last_block = uopt.lastblock;
sbi->s_anchor[0] = sbi->s_anchor[1] = 0;
sbi->s_anchor[2] = uopt.anchor;
sbi->s_anchor[3] = 256;

if (udf_check_valid(sb, uopt.novrs, silent)) {
/* read volume recognition sequences */
Expand Down
2 changes: 1 addition & 1 deletion trunk/fs/udf/udf_sb.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -100,7 +100,7 @@ struct udf_sb_info {

/* Sector headers */
__s32 s_session;
__u32 s_anchor[4];
__u32 s_anchor[3];
__u32 s_last_block;

struct buffer_head *s_lvid_bh;
Expand Down

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