* [f2fs-dev] [PATCH] fs: introduce is_dot_dotdot helper for cleanup
@ 2019-12-02 10:10 Tiezhu Yang
[not found] ` <20191202200302.GN20752@bombadil.infradead.org>
0 siblings, 1 reply; 6+ messages in thread
From: Tiezhu Yang @ 2019-12-02 10:10 UTC (permalink / raw)
To: Alexander Viro, Theodore Y. Ts'o, Jaegeuk Kim, Chao Yu,
Eric Biggers, Tyler Hicks
Cc: linux-fsdevel, linux-fscrypt, ecryptfs, linux-kernel, linux-f2fs-devel
There exists many similar and duplicate codes to check "." and "..",
so introduce is_dot_dotdot helper to make the code more clean.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
fs/crypto/fname.c | 15 ++-------------
fs/ecryptfs/crypto.c | 13 ++-----------
fs/f2fs/f2fs.h | 11 -----------
fs/libfs.c | 12 ++++++++++++
fs/namei.c | 6 ++----
include/linux/fs.h | 2 ++
6 files changed, 20 insertions(+), 39 deletions(-)
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 3da3707..36be864 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -15,17 +15,6 @@
#include <crypto/skcipher.h>
#include "fscrypt_private.h"
-static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
-{
- if (str->len == 1 && str->name[0] == '.')
- return true;
-
- if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
- return true;
-
- return false;
-}
-
/**
* fname_encrypt() - encrypt a filename
*
@@ -255,7 +244,7 @@ int fscrypt_fname_disk_to_usr(struct inode *inode,
const struct qstr qname = FSTR_TO_QSTR(iname);
struct fscrypt_digested_name digested_name;
- if (fscrypt_is_dot_dotdot(&qname)) {
+ if (is_dot_dotdot(&qname)) {
oname->name[0] = '.';
oname->name[iname->len - 1] = '.';
oname->len = iname->len;
@@ -323,7 +312,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
memset(fname, 0, sizeof(struct fscrypt_name));
fname->usr_fname = iname;
- if (!IS_ENCRYPTED(dir) || fscrypt_is_dot_dotdot(iname)) {
+ if (!IS_ENCRYPTED(dir) || is_dot_dotdot(iname)) {
fname->disk_name.name = (unsigned char *)iname->name;
fname->disk_name.len = iname->len;
return 0;
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f91db24..6f4db74 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1991,16 +1991,6 @@ int ecryptfs_encrypt_and_encode_filename(
return rc;
}
-static bool is_dot_dotdot(const char *name, size_t name_size)
-{
- if (name_size == 1 && name[0] == '.')
- return true;
- else if (name_size == 2 && name[0] == '.' && name[1] == '.')
- return true;
-
- return false;
-}
-
/**
* ecryptfs_decode_and_decrypt_filename - converts the encoded cipher text name to decoded plaintext
* @plaintext_name: The plaintext name
@@ -2020,6 +2010,7 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name,
{
struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
&ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
+ const struct qstr file_name = {.name = name, .len = name_size};
char *decoded_name;
size_t decoded_name_size;
size_t packet_size;
@@ -2027,7 +2018,7 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name,
if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) &&
!(mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)) {
- if (is_dot_dotdot(name, name_size)) {
+ if (is_dot_dotdot(&file_name)) {
rc = ecryptfs_copy_filename(plaintext_name,
plaintext_name_size,
name, name_size);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5a888a0..3d5e684 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2767,17 +2767,6 @@ static inline bool f2fs_cp_error(struct f2fs_sb_info *sbi)
return is_set_ckpt_flags(sbi, CP_ERROR_FLAG);
}
-static inline bool is_dot_dotdot(const struct qstr *str)
-{
- if (str->len == 1 && str->name[0] == '.')
- return true;
-
- if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
- return true;
-
- return false;
-}
-
static inline bool f2fs_may_extent_tree(struct inode *inode)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
diff --git a/fs/libfs.c b/fs/libfs.c
index 1463b03..876b1b6 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1291,3 +1291,15 @@ bool is_empty_dir_inode(struct inode *inode)
return (inode->i_fop == &empty_dir_operations) &&
(inode->i_op == &empty_dir_inode_operations);
}
+
+bool is_dot_dotdot(const struct qstr *str)
+{
+ if (str->len == 1 && str->name[0] == '.')
+ return true;
+
+ if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL(is_dot_dotdot);
diff --git a/fs/namei.c b/fs/namei.c
index 2dda552..7730a3b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2458,10 +2458,8 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
if (!len)
return -EACCES;
- if (unlikely(name[0] == '.')) {
- if (len < 2 || (len == 2 && name[1] == '.'))
- return -EACCES;
- }
+ if (unlikely(is_dot_dotdot(this)))
+ return -EACCES;
while (len--) {
unsigned int c = *(const unsigned char *)name++;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c159a8b..e999826 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3627,4 +3627,6 @@ static inline int inode_drain_writes(struct inode *inode)
return filemap_write_and_wait(inode->i_mapping);
}
+extern bool is_dot_dotdot(const struct qstr *str);
+
#endif /* _LINUX_FS_H */
--
2.1.0
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^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH] fs: introduce is_dot_dotdot helper for cleanup
[not found] ` <20191202200302.GN20752@bombadil.infradead.org>
@ 2019-12-03 2:07 ` Tiezhu Yang
2019-12-03 2:39 ` Darrick J. Wong
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Tiezhu Yang @ 2019-12-03 2:07 UTC (permalink / raw)
To: Matthew Wilcox
Cc: ecryptfs, Theodore Y. Ts'o, linux-kernel, Tyler Hicks,
Eric Biggers, linux-fscrypt, Alexander Viro, linux-fsdevel,
Jaegeuk Kim, linux-f2fs-devel
On 12/03/2019 04:03 AM, Matthew Wilcox wrote:
> On Mon, Dec 02, 2019 at 06:10:13PM +0800, Tiezhu Yang wrote:
>> There exists many similar and duplicate codes to check "." and "..",
>> so introduce is_dot_dotdot helper to make the code more clean.
> The idea is good. The implementation is, I'm afraid, badly chosen.
> Did you benchmark this change at all? In general, you should prefer the
> core kernel implementation to that of some less-interesting filesystems.
> I measured the performance with the attached test program on my laptop
> (Core-i7 Kaby Lake):
>
> qstr . time_1 0.020531 time_2 0.005786
> qstr .. time_1 0.017892 time_2 0.008798
> qstr a time_1 0.017633 time_2 0.003634
> qstr matthew time_1 0.011820 time_2 0.003605
> qstr .a time_1 0.017909 time_2 0.008710
> qstr , time_1 0.017631 time_2 0.003619
>
> The results are quite stable:
>
> qstr . time_1 0.021137 time_2 0.005780
> qstr .. time_1 0.017964 time_2 0.008675
> qstr a time_1 0.017899 time_2 0.003654
> qstr matthew time_1 0.011821 time_2 0.003620
> qstr .a time_1 0.017889 time_2 0.008662
> qstr , time_1 0.017764 time_2 0.003613
>
> Feel free to suggest some different strings we could use for testing.
> These seemed like interesting strings to test with. It's always possible
> I've messed up something with this benchmark that causes it to not
> accurately represent the performance of each algorithm, so please check
> that too.
[Sorry to resend this email because the mail list server
was denied due to it is not plain text.]
Hi Matthew,
Thanks for your reply and suggestion. I measured the
performance with the test program, the following
implementation is better for various of test cases:
bool is_dot_dotdot(const struct qstr *str)
{
if (unlikely(str->name[0] == '.')) {
if (str->len < 2 || (str->len == 2 && str->name[1] == '.'))
return true;
}
return false;
}
I will send a v2 patch used with this implementation.
Thanks,
Tiezhu Yang
>
>> +bool is_dot_dotdot(const struct qstr *str)
>> +{
>> + if (str->len == 1 && str->name[0] == '.')
>> + return true;
>> +
>> + if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
>> + return true;
>> +
>> + return false;
>> +}
>> +EXPORT_SYMBOL(is_dot_dotdot);
>> diff --git a/fs/namei.c b/fs/namei.c
>> index 2dda552..7730a3b 100644
>> --- a/fs/namei.c
>> +++ b/fs/namei.c
>> @@ -2458,10 +2458,8 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
>> if (!len)
>> return -EACCES;
>>
>> - if (unlikely(name[0] == '.')) {
>> - if (len < 2 || (len == 2 && name[1] == '.'))
>> - return -EACCES;
>> - }
>> + if (unlikely(is_dot_dotdot(this)))
>> + return -EACCES;
>>
>> while (len--) {
>> unsigned int c = *(const unsigned char *)name++;
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH] fs: introduce is_dot_dotdot helper for cleanup
2019-12-03 2:07 ` Tiezhu Yang
@ 2019-12-03 2:39 ` Darrick J. Wong
2019-12-03 8:33 ` Tiezhu Yang
2019-12-03 2:46 ` Matthew Wilcox
2019-12-04 13:06 ` Jean-Louis Biasini via Linux-f2fs-devel
2 siblings, 1 reply; 6+ messages in thread
From: Darrick J. Wong @ 2019-12-03 2:39 UTC (permalink / raw)
To: Tiezhu Yang
Cc: ecryptfs, Theodore Y. Ts'o, linux-kernel, Matthew Wilcox,
Tyler Hicks, Eric Biggers, linux-fscrypt, Alexander Viro,
linux-fsdevel, Jaegeuk Kim, linux-f2fs-devel
On Tue, Dec 03, 2019 at 10:07:41AM +0800, Tiezhu Yang wrote:
> On 12/03/2019 04:03 AM, Matthew Wilcox wrote:
> > On Mon, Dec 02, 2019 at 06:10:13PM +0800, Tiezhu Yang wrote:
> > > There exists many similar and duplicate codes to check "." and "..",
> > > so introduce is_dot_dotdot helper to make the code more clean.
> > The idea is good. The implementation is, I'm afraid, badly chosen.
> > Did you benchmark this change at all? In general, you should prefer the
> > core kernel implementation to that of some less-interesting filesystems.
> > I measured the performance with the attached test program on my laptop
> > (Core-i7 Kaby Lake):
> >
> > qstr . time_1 0.020531 time_2 0.005786
> > qstr .. time_1 0.017892 time_2 0.008798
> > qstr a time_1 0.017633 time_2 0.003634
> > qstr matthew time_1 0.011820 time_2 0.003605
> > qstr .a time_1 0.017909 time_2 0.008710
> > qstr , time_1 0.017631 time_2 0.003619
> >
> > The results are quite stable:
> >
> > qstr . time_1 0.021137 time_2 0.005780
> > qstr .. time_1 0.017964 time_2 0.008675
> > qstr a time_1 0.017899 time_2 0.003654
> > qstr matthew time_1 0.011821 time_2 0.003620
> > qstr .a time_1 0.017889 time_2 0.008662
> > qstr , time_1 0.017764 time_2 0.003613
> >
> > Feel free to suggest some different strings we could use for testing.
> > These seemed like interesting strings to test with. It's always possible
> > I've messed up something with this benchmark that causes it to not
> > accurately represent the performance of each algorithm, so please check
> > that too.
>
> [Sorry to resend this email because the mail list server
> was denied due to it is not plain text.]
>
> Hi Matthew,
>
> Thanks for your reply and suggestion. I measured the
> performance with the test program, the following
> implementation is better for various of test cases:
>
> bool is_dot_dotdot(const struct qstr *str)
> {
> if (unlikely(str->name[0] == '.')) {
> if (str->len < 2 || (str->len == 2 && str->name[1] == '.'))
> return true;
> }
>
> return false;
> }
>
> I will send a v2 patch used with this implementation.
Can you make it a static inline since it's such a short function?
--D
> Thanks,
>
> Tiezhu Yang
>
> >
> > > +bool is_dot_dotdot(const struct qstr *str)
> > > +{
> > > + if (str->len == 1 && str->name[0] == '.')
> > > + return true;
> > > +
> > > + if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
> > > + return true;
> > > +
> > > + return false;
> > > +}
> > > +EXPORT_SYMBOL(is_dot_dotdot);
> > > diff --git a/fs/namei.c b/fs/namei.c
> > > index 2dda552..7730a3b 100644
> > > --- a/fs/namei.c
> > > +++ b/fs/namei.c
> > > @@ -2458,10 +2458,8 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
> > > if (!len)
> > > return -EACCES;
> > > - if (unlikely(name[0] == '.')) {
> > > - if (len < 2 || (len == 2 && name[1] == '.'))
> > > - return -EACCES;
> > > - }
> > > + if (unlikely(is_dot_dotdot(this)))
> > > + return -EACCES;
> > > while (len--) {
> > > unsigned int c = *(const unsigned char *)name++;
>
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https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH] fs: introduce is_dot_dotdot helper for cleanup
2019-12-03 2:07 ` Tiezhu Yang
2019-12-03 2:39 ` Darrick J. Wong
@ 2019-12-03 2:46 ` Matthew Wilcox
2019-12-04 13:06 ` Jean-Louis Biasini via Linux-f2fs-devel
2 siblings, 0 replies; 6+ messages in thread
From: Matthew Wilcox @ 2019-12-03 2:46 UTC (permalink / raw)
To: Tiezhu Yang
Cc: ecryptfs, Theodore Y. Ts'o, linux-kernel, Tyler Hicks,
Eric Biggers, linux-fscrypt, Alexander Viro, linux-fsdevel,
Jaegeuk Kim, linux-f2fs-devel
On Tue, Dec 03, 2019 at 10:07:41AM +0800, Tiezhu Yang wrote:
> On 12/03/2019 04:03 AM, Matthew Wilcox wrote:
> > On Mon, Dec 02, 2019 at 06:10:13PM +0800, Tiezhu Yang wrote:
> > > There exists many similar and duplicate codes to check "." and "..",
> > > so introduce is_dot_dotdot helper to make the code more clean.
> > The idea is good. The implementation is, I'm afraid, badly chosen.
> > Did you benchmark this change at all? In general, you should prefer the
>
> Thanks for your reply and suggestion. I measured the
> performance with the test program, the following
> implementation is better for various of test cases:
>
> bool is_dot_dotdot(const struct qstr *str)
> {
> if (unlikely(str->name[0] == '.')) {
> if (str->len < 2 || (str->len == 2 && str->name[1] == '.'))
> return true;
> }
>
> return false;
> }
>
> I will send a v2 patch used with this implementation.
Well, hang on. If you haven't done any benchmarking, please do so
before sending a v2. In particular, you've now moved this to being a
function call. That might slow things down, or it might speed things up.
I also don't know if passing a qstr is going to be the right API --
let's hear from the filesystems affected by the API change that they're
OK with this change.
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH] fs: introduce is_dot_dotdot helper for cleanup
2019-12-03 2:39 ` Darrick J. Wong
@ 2019-12-03 8:33 ` Tiezhu Yang
0 siblings, 0 replies; 6+ messages in thread
From: Tiezhu Yang @ 2019-12-03 8:33 UTC (permalink / raw)
To: Darrick J. Wong
Cc: ecryptfs, Theodore Y. Ts'o, linux-kernel, Matthew Wilcox,
Tyler Hicks, Eric Biggers, linux-fscrypt, Alexander Viro,
linux-fsdevel, Jaegeuk Kim, linux-f2fs-devel
On 12/03/2019 10:39 AM, Darrick J. Wong wrote:
> On Tue, Dec 03, 2019 at 10:07:41AM +0800, Tiezhu Yang wrote:
>> On 12/03/2019 04:03 AM, Matthew Wilcox wrote:
>>> On Mon, Dec 02, 2019 at 06:10:13PM +0800, Tiezhu Yang wrote:
>>>> There exists many similar and duplicate codes to check "." and "..",
>>>> so introduce is_dot_dotdot helper to make the code more clean.
>>> The idea is good. The implementation is, I'm afraid, badly chosen.
>>> Did you benchmark this change at all? In general, you should prefer the
>>> core kernel implementation to that of some less-interesting filesystems.
>>> I measured the performance with the attached test program on my laptop
>>> (Core-i7 Kaby Lake):
>>>
>>> qstr . time_1 0.020531 time_2 0.005786
>>> qstr .. time_1 0.017892 time_2 0.008798
>>> qstr a time_1 0.017633 time_2 0.003634
>>> qstr matthew time_1 0.011820 time_2 0.003605
>>> qstr .a time_1 0.017909 time_2 0.008710
>>> qstr , time_1 0.017631 time_2 0.003619
>>>
>>> The results are quite stable:
>>>
>>> qstr . time_1 0.021137 time_2 0.005780
>>> qstr .. time_1 0.017964 time_2 0.008675
>>> qstr a time_1 0.017899 time_2 0.003654
>>> qstr matthew time_1 0.011821 time_2 0.003620
>>> qstr .a time_1 0.017889 time_2 0.008662
>>> qstr , time_1 0.017764 time_2 0.003613
>>>
>>> Feel free to suggest some different strings we could use for testing.
>>> These seemed like interesting strings to test with. It's always possible
>>> I've messed up something with this benchmark that causes it to not
>>> accurately represent the performance of each algorithm, so please check
>>> that too.
>> [Sorry to resend this email because the mail list server
>> was denied due to it is not plain text.]
>>
>> Hi Matthew,
>>
>> Thanks for your reply and suggestion. I measured the
>> performance with the test program, the following
>> implementation is better for various of test cases:
>>
>> bool is_dot_dotdot(const struct qstr *str)
>> {
>> if (unlikely(str->name[0] == '.')) {
>> if (str->len < 2 || (str->len == 2 && str->name[1] == '.'))
>> return true;
>> }
>>
>> return false;
>> }
>>
>> I will send a v2 patch used with this implementation.
> Can you make it a static inline since it's such a short function?
Thanks for your suggestion, I will make it static inline and
move it to include/linux/fs.h in the v2 patch.
Thanks,
Tiezhu Yang
>
> --D
>
>> Thanks,
>>
>> Tiezhu Yang
>>
>>>> +bool is_dot_dotdot(const struct qstr *str)
>>>> +{
>>>> + if (str->len == 1 && str->name[0] == '.')
>>>> + return true;
>>>> +
>>>> + if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
>>>> + return true;
>>>> +
>>>> + return false;
>>>> +}
>>>> +EXPORT_SYMBOL(is_dot_dotdot);
>>>> diff --git a/fs/namei.c b/fs/namei.c
>>>> index 2dda552..7730a3b 100644
>>>> --- a/fs/namei.c
>>>> +++ b/fs/namei.c
>>>> @@ -2458,10 +2458,8 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
>>>> if (!len)
>>>> return -EACCES;
>>>> - if (unlikely(name[0] == '.')) {
>>>> - if (len < 2 || (len == 2 && name[1] == '.'))
>>>> - return -EACCES;
>>>> - }
>>>> + if (unlikely(is_dot_dotdot(this)))
>>>> + return -EACCES;
>>>> while (len--) {
>>>> unsigned int c = *(const unsigned char *)name++;
_______________________________________________
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Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [f2fs-dev] [PATCH] fs: introduce is_dot_dotdot helper for cleanup
2019-12-03 2:07 ` Tiezhu Yang
2019-12-03 2:39 ` Darrick J. Wong
2019-12-03 2:46 ` Matthew Wilcox
@ 2019-12-04 13:06 ` Jean-Louis Biasini via Linux-f2fs-devel
2 siblings, 0 replies; 6+ messages in thread
From: Jean-Louis Biasini via Linux-f2fs-devel @ 2019-12-04 13:06 UTC (permalink / raw)
To: Tiezhu Yang, Matthew Wilcox
Cc: ecryptfs, Theodore Y. Ts'o, linux-kernel, Tyler Hicks,
Eric Biggers, linux-fscrypt, Alexander Viro, linux-fsdevel,
Jaegeuk Kim, linux-f2fs-devel
Please UNSUBSCRIBE ME from this list of tell how to!!!
Le 03/12/2019 à 03:07, Tiezhu Yang a écrit :
> On 12/03/2019 04:03 AM, Matthew Wilcox wrote:
>> On Mon, Dec 02, 2019 at 06:10:13PM +0800, Tiezhu Yang wrote:
>>> There exists many similar and duplicate codes to check "." and "..",
>>> so introduce is_dot_dotdot helper to make the code more clean.
>> The idea is good. The implementation is, I'm afraid, badly chosen.
>> Did you benchmark this change at all? In general, you should prefer the
>> core kernel implementation to that of some less-interesting filesystems.
>> I measured the performance with the attached test program on my laptop
>> (Core-i7 Kaby Lake):
>>
>> qstr . time_1 0.020531 time_2 0.005786
>> qstr .. time_1 0.017892 time_2 0.008798
>> qstr a time_1 0.017633 time_2 0.003634
>> qstr matthew time_1 0.011820 time_2 0.003605
>> qstr .a time_1 0.017909 time_2 0.008710
>> qstr , time_1 0.017631 time_2 0.003619
>>
>> The results are quite stable:
>>
>> qstr . time_1 0.021137 time_2 0.005780
>> qstr .. time_1 0.017964 time_2 0.008675
>> qstr a time_1 0.017899 time_2 0.003654
>> qstr matthew time_1 0.011821 time_2 0.003620
>> qstr .a time_1 0.017889 time_2 0.008662
>> qstr , time_1 0.017764 time_2 0.003613
>>
>> Feel free to suggest some different strings we could use for testing.
>> These seemed like interesting strings to test with. It's always
>> possible
>> I've messed up something with this benchmark that causes it to not
>> accurately represent the performance of each algorithm, so please check
>> that too.
>
> [Sorry to resend this email because the mail list server
> was denied due to it is not plain text.]
>
> Hi Matthew,
>
> Thanks for your reply and suggestion. I measured the
> performance with the test program, the following
> implementation is better for various of test cases:
>
> bool is_dot_dotdot(const struct qstr *str)
> {
> if (unlikely(str->name[0] == '.')) {
> if (str->len < 2 || (str->len == 2 && str->name[1] ==
> '.'))
> return true;
> }
>
> return false;
> }
>
> I will send a v2 patch used with this implementation.
>
> Thanks,
>
> Tiezhu Yang
>
>>
>>> +bool is_dot_dotdot(const struct qstr *str)
>>> +{
>>> + if (str->len == 1 && str->name[0] == '.')
>>> + return true;
>>> +
>>> + if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
>>> + return true;
>>> +
>>> + return false;
>>> +}
>>> +EXPORT_SYMBOL(is_dot_dotdot);
>>> diff --git a/fs/namei.c b/fs/namei.c
>>> index 2dda552..7730a3b 100644
>>> --- a/fs/namei.c
>>> +++ b/fs/namei.c
>>> @@ -2458,10 +2458,8 @@ static int lookup_one_len_common(const char
>>> *name, struct dentry *base,
>>> if (!len)
>>> return -EACCES;
>>> - if (unlikely(name[0] == '.')) {
>>> - if (len < 2 || (len == 2 && name[1] == '.'))
>>> - return -EACCES;
>>> - }
>>> + if (unlikely(is_dot_dotdot(this)))
>>> + return -EACCES;
>>> while (len--) {
>>> unsigned int c = *(const unsigned char *)name++;
>
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-12-04 13:06 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-12-02 10:10 [f2fs-dev] [PATCH] fs: introduce is_dot_dotdot helper for cleanup Tiezhu Yang
[not found] ` <20191202200302.GN20752@bombadil.infradead.org>
2019-12-03 2:07 ` Tiezhu Yang
2019-12-03 2:39 ` Darrick J. Wong
2019-12-03 8:33 ` Tiezhu Yang
2019-12-03 2:46 ` Matthew Wilcox
2019-12-04 13:06 ` Jean-Louis Biasini via Linux-f2fs-devel
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