From: "Theodore Ts'o" <tytso@mit.edu>
To: Ext4 Developers List <linux-ext4@vger.kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Subject: [PATCH] ext4: optimize __ext4_check_dir_entry()
Date: Sun, 8 Dec 2019 19:43:46 -0500 [thread overview]
Message-ID: <20191209004346.38526-1-tytso@mit.edu> (raw)
In-Reply-To: <20191202170213.4761-3-jack@suse.cz>
Make __ext4_check_dir_entry() a bit easier to understand, and reduce
the object size of the function by over 11%.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
As a follow-up to "ext4: check for directory entries too close to block end"
fs/ext4/dir.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 6305d5ec25af..9f00fc0bf21d 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -72,6 +72,7 @@ int __ext4_check_dir_entry(const char *function, unsigned int line,
const char *error_msg = NULL;
const int rlen = ext4_rec_len_from_disk(de->rec_len,
dir->i_sb->s_blocksize);
+ const int next_offset = ((char *) de - buf) + rlen;
if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
error_msg = "rec_len is smaller than minimal";
@@ -79,13 +80,11 @@ int __ext4_check_dir_entry(const char *function, unsigned int line,
error_msg = "rec_len % 4 != 0";
else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
error_msg = "rec_len is too small for name_len";
- else if (unlikely(((char *) de - buf) + rlen > size))
+ else if (unlikely(next_offset > size))
error_msg = "directory entry overrun";
- else if (unlikely(((char *) de - buf) + rlen >
- size - EXT4_DIR_REC_LEN(1) &&
- ((char *) de - buf) + rlen != size)) {
+ else if (unlikely(next_offset > size - EXT4_DIR_REC_LEN(1) &&
+ next_offset != size))
error_msg = "directory entry too close to block end";
- }
else if (unlikely(le32_to_cpu(de->inode) >
le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
error_msg = "inode out of bounds";
--
2.23.0
prev parent reply other threads:[~2019-12-09 0:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-02 17:02 [PATCH 0/2 v2] ext4: Handle directories with holes better Jan Kara
2019-12-02 17:02 ` [PATCH 1/2] ext4: Fix ext4_empty_dir() for directories with holes Jan Kara
2019-12-09 0:12 ` Theodore Y. Ts'o
2019-12-02 17:02 ` [PATCH 2/2] ext4: Check for directory entries too close to block end Jan Kara
2019-12-09 0:42 ` Theodore Y. Ts'o
2019-12-09 0:43 ` Theodore Ts'o [this message]
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