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Subject[PATCH 09/16] udf: create common function for tag checksumming
Date
From
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
CC: Jan Kara <jack@suse.cz>
CC: Christoph Hellwig <hch@infradead.org>
---
fs/udf/inode.c | 15 ++-------------
fs/udf/misc.c | 35 ++++++++++++++---------------------
fs/udf/namei.c | 9 +--------
fs/udf/super.c | 16 ++--------------
fs/udf/udfdecl.h | 3 +++
5 files changed, 22 insertions(+), 56 deletions(-)
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 9adde18..6751945 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1440,7 +1440,6 @@ static int udf_update_inode(struct inode *inode, int do_sync)
uint32_t udfperms;
uint16_t icbflags;
uint16_t crclen;
- int i;
kernel_timestamp cpu_time;
int err = 0;
struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
@@ -1476,12 +1475,7 @@ static int udf_update_inode(struct inode *inode, int do_sync)
use->descTag.descCRC = cpu_to_le16(udf_crc((char *)use +
sizeof(tag), crclen,
0));
-
- use->descTag.tagChecksum = 0;
- for (i = 0; i < 16; i++)
- if (i != 4)
- use->descTag.tagChecksum +=
- ((uint8_t *)&(use->descTag))[i];
+ use->descTag.tagChecksum = udf_tag_checksum(&use->descTag);

mark_buffer_dirty(bh);
brelse(bh);
@@ -1650,12 +1644,7 @@ static int udf_update_inode(struct inode *inode, int do_sync)
fe->descTag.descCRCLength = cpu_to_le16(crclen);
fe->descTag.descCRC = cpu_to_le16(udf_crc((char *)fe + sizeof(tag),
crclen, 0));
-
- fe->descTag.tagChecksum = 0;
- for (i = 0; i < 16; i++)
- if (i != 4)
- fe->descTag.tagChecksum +=
- ((uint8_t *)&(fe->descTag))[i];
+ fe->descTag.tagChecksum = udf_tag_checksum(&fe->descTag);

/* write the data blocks */
mark_buffer_dirty(bh);
diff --git a/fs/udf/misc.c b/fs/udf/misc.c
index a0bf415..585e4ea 100644
--- a/fs/udf/misc.c
+++ b/fs/udf/misc.c
@@ -51,7 +51,6 @@ struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
uint8_t *ea = NULL, *ad = NULL;
int offset;
uint16_t crclen;
- int i;

ea = UDF_I_DATA(inode);
if (UDF_I_LENEATTR(inode)) {
@@ -138,11 +137,7 @@ struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
eahd->descTag.descCRCLength = cpu_to_le16(crclen);
eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd +
sizeof(tag), crclen, 0));
- eahd->descTag.tagChecksum = 0;
- for (i = 0; i < 16; i++)
- if (i != 4)
- eahd->descTag.tagChecksum +=
- ((uint8_t *)&(eahd->descTag))[i];
+ eahd->descTag.tagChecksum = udf_tag_checksum(&eahd->descTag);
UDF_I_LENEATTR(inode) += size;
return (struct genericFormat *)&ea[offset];
}
@@ -207,8 +202,6 @@ struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block,
{
tag *tag_p;
struct buffer_head *bh = NULL;
- register uint8_t checksum;
- register int i;
struct udf_sb_info *sbi = UDF_SB(sb);

/* Read the block */
@@ -234,12 +227,7 @@ struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block,
}

/* Verify the tag checksum */
- checksum = 0U;
- for (i = 0; i < 4; i++)
- checksum += (uint8_t)(bh->b_data[i]);
- for (i = 5; i < 16; i++)
- checksum += (uint8_t)(bh->b_data[i]);
- if (checksum != tag_p->tagChecksum) {
+ if (udf_tag_checksum(tag_p) != tag_p->tagChecksum) {
printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
goto error_out;
}
@@ -277,17 +265,11 @@ struct buffer_head *udf_read_ptagged(struct super_block *sb, kernel_lb_addr loc,
void udf_update_tag(char *data, int length)
{
tag *tptr = (tag *)data;
- int i;
-
length -= sizeof(tag);

- tptr->tagChecksum = 0;
tptr->descCRCLength = cpu_to_le16(length);
tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0));
-
- for (i = 0; i < 16; i++)
- if (i != 4)
- tptr->tagChecksum += (uint8_t)(data[i]);
+ tptr->tagChecksum = udf_tag_checksum(tptr);
}

void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
@@ -300,3 +282,14 @@ void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
tptr->tagLocation = cpu_to_le32(loc);
udf_update_tag(data, length);
}
+
+u8 udf_tag_checksum(const tag *t)
+{
+ u8 *data = (u8 *)t;
+ u8 checksum = 0;
+ int i;
+ for (i = 0; i < sizeof(tag); ++i)
+ if (i != 4) /* position of checksum */
+ checksum += data[i];
+ return checksum;
+}
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 25d518b..f1cf18f 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -47,8 +47,6 @@ int udf_write_fi(struct inode *inode, struct fileIdentDesc *cfi,
{
uint16_t crclen = fibh->eoffset - fibh->soffset - sizeof(tag);
uint16_t crc;
- uint8_t checksum = 0;
- int i;
int offset;
uint16_t liu = le16_to_cpu(cfi->lengthOfImpUse);
uint8_t lfi = cfi->lengthFileIdent;
@@ -122,13 +120,8 @@ int udf_write_fi(struct inode *inode, struct fileIdentDesc *cfi,

cfi->descTag.descCRC = cpu_to_le16(crc);
cfi->descTag.descCRCLength = cpu_to_le16(crclen);
+ cfi->descTag.tagChecksum = udf_tag_checksum(&cfi->descTag);

- for (i = 0; i < 16; i++) {
- if (i != 4)
- checksum += ((uint8_t *)&cfi->descTag)[i];
- }
-
- cfi->descTag.tagChecksum = checksum;
if (adinicb || (sizeof(struct fileIdentDesc) <= -fibh->soffset)) {
memcpy((uint8_t *)sfi, (uint8_t *)cfi,
sizeof(struct fileIdentDesc));
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 7f75a94..12fb91d 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1564,7 +1564,6 @@ static void udf_open_lvid(struct super_block *sb)
struct udf_sb_info *sbi = UDF_SB(sb);
struct buffer_head *bh = sbi->s_lvid_bh;
if (bh) {
- int i;
kernel_timestamp cpu_time;
struct logicalVolIntegrityDesc *lvid =
(struct logicalVolIntegrityDesc *)bh->b_data;
@@ -1582,12 +1581,7 @@ static void udf_open_lvid(struct super_block *sb)
le16_to_cpu(lvid->descTag.descCRCLength),
0));

- lvid->descTag.tagChecksum = 0;
- for (i = 0; i < 16; i++)
- if (i != 4)
- lvid->descTag.tagChecksum +=
- ((uint8_t *) &(lvid->descTag))[i];
-
+ lvid->descTag.tagChecksum = udf_tag_checksum(&lvid->descTag);
mark_buffer_dirty(bh);
}
}
@@ -1595,7 +1589,6 @@ static void udf_open_lvid(struct super_block *sb)
static void udf_close_lvid(struct super_block *sb)
{
kernel_timestamp cpu_time;
- int i;
struct udf_sb_info *sbi = UDF_SB(sb);
struct buffer_head *bh = sbi->s_lvid_bh;
struct logicalVolIntegrityDesc *lvid;
@@ -1626,12 +1619,7 @@ static void udf_close_lvid(struct super_block *sb)
le16_to_cpu(lvid->descTag.descCRCLength),
0));

- lvid->descTag.tagChecksum = 0;
- for (i = 0; i < 16; i++)
- if (i != 4)
- lvid->descTag.tagChecksum +=
- ((uint8_t *)&(lvid->descTag))[i];
-
+ lvid->descTag.tagChecksum = udf_tag_checksum(&lvid->descTag);
mark_buffer_dirty(bh);
}
}
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index b17ca67..005e3ad 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -36,6 +36,9 @@

#define udf_get_lb_pblock(sb,loc,offset) udf_get_pblock((sb), (loc).logicalBlockNum, (loc).partitionReferenceNum, (offset))

+/* computes tag checksum */
+u8 udf_tag_checksum(const tag *t);
+
struct dentry;
struct inode;
struct task_struct;
--
1.5.3.7


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