From 3f2587bb22bbcd679e9cf034fb4a29bb48b051b3 Mon Sep 17 00:00:00 2001 From: Marcin Slusarz Date: Fri, 8 Feb 2008 04:20:39 -0800 Subject: [PATCH] udf: create common function for tag checksumming Signed-off-by: Marcin Slusarz Acked-by: Jan Kara Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 3ce2f6d1aa..42783da9cf 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 a0bf4158f1..585e4eaed2 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 a126950d79..9b5cfc5f72 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 7f75a949e1..12fb91d23a 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 c8016cc9e7..bed0a02513 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; -- 2.39.5