Messages in this thread Patch in this message |  | | Subject | [PATCH 2/2] fs-qnx6: Less checks in qnx6_mmi_fill_super() after error detection | From | SF Markus Elfring <> | Date | Wed, 16 Aug 2017 18:15:57 +0200 |
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From: Markus Elfring <elfring@users.sourceforge.net> Date: Wed, 16 Aug 2017 18:00:24 +0200
Two pointer checks could be repeated by the qnx6_mmi_fill_super() function during error handling even if the relevant properties can be determined for the involved variables before by source code analysis.
* Adjust jump targets so that extra checks can be omitted at the end.
* Delete an initialisation for the variables "bh2" and "qsb" which became unnecessary with this refactoring.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> --- fs/qnx6/super_mmi.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-)
diff --git a/fs/qnx6/super_mmi.c b/fs/qnx6/super_mmi.c index fdcfc99e2db6..eb98479f9ec1 100644 --- a/fs/qnx6/super_mmi.c +++ b/fs/qnx6/super_mmi.c @@ -34,9 +34,9 @@ static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb, struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) { - struct buffer_head *bh1, *bh2 = NULL; + struct buffer_head *bh1, *bh2; struct qnx6_mmi_super_block *sb1, *sb2; - struct qnx6_super_block *qsb = NULL; + struct qnx6_super_block *qsb; struct qnx6_sb_info *sbi; __u64 offset; @@ -52,7 +52,7 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) { if (!silent) { pr_err("wrong signature (magic) in superblock #1.\n"); - goto out; + goto brelse_first; } } @@ -60,7 +60,7 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) if (fs32_to_cpu(sbi, sb1->sb_checksum) != crc32_be(0, (char *)(bh1->b_data + 8), 504)) { pr_err("superblock #1 checksum error\n"); - goto out; + goto brelse_first; } /* calculate second superblock blocknumber */ @@ -70,38 +70,38 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) /* set new blocksize */ if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) { pr_err("unable to set blocksize\n"); - goto out; + goto brelse_first; } /* blocksize invalidates bh - pull it back in */ brelse(bh1); bh1 = sb_bread(s, 0); if (!bh1) - goto out; + goto exit; sb1 = (struct qnx6_mmi_super_block *)bh1->b_data; /* read second superblock */ bh2 = sb_bread(s, offset); if (!bh2) { pr_err("unable to read the second superblock\n"); - goto out; + goto brelse_first; } sb2 = (struct qnx6_mmi_super_block *)bh2->b_data; if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) { if (!silent) pr_err("wrong signature (magic) in superblock #2.\n"); - goto out; + goto brelse_second; } /* checksum check - start at byte 8 and end at byte 512 */ if (fs32_to_cpu(sbi, sb2->sb_checksum) != crc32_be(0, (char *)(bh2->b_data + 8), 504)) { pr_err("superblock #1 checksum error\n"); - goto out; + goto brelse_second; } qsb = kmalloc(sizeof(*qsb), GFP_KERNEL); if (!qsb) - goto out; + goto brelse_second; if (fs64_to_cpu(sbi, sb1->sb_serial) > fs64_to_cpu(sbi, sb2->sb_serial)) { @@ -136,11 +136,10 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) /* success */ return sbi->sb; - -out: - if (bh1 != NULL) - brelse(bh1); - if (bh2 != NULL) - brelse(bh2); +brelse_second: + brelse(bh2); +brelse_first: + brelse(bh1); +exit: return NULL; } -- 2.14.0
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