Close #I4BL3S
Signed-off-by: NFar <yesiyuan2@huawei.com>

1, change the owner of page to vnode
2, save the file path in vnode

close: #I44TBS
Signed-off-by: NLeon Chan <chenwei26@huawei.com>

Signed-off-by: Njason_gitee <yangjie140@huawei.com>

首先，POSIX规范规定文件描述符需要支持close-on-exec属性，修改前的vfs不支持close-on-exec，当exec系列函数执行时，进程所有的文件将会被关闭（0，1，2也重新被打开）。但是，系统有些时候是不能在exec时关闭全部文件的，例如在执行exec之前，就需要重定向进程的某些文件描述符时（使用dup2），就希望该文件不被关闭，继续保持重定向属性，shell执行进程并重定向其标准输出到文件，这是我们经常做的事情。

BREAKING CHANGE:
执行exec类函数后，进程拥有的文件描述符情况发生变化：修改前，默认关闭所有的进程文件描述符，0，1，2重新打开；修改后，除非文件描述符拥有FD_CLOEXEC标记，否则该描述符不会被关闭。

re #I3U81W

Change-Id: I54e841ac88e9835ec23e97de0cbc906c4e11f5a4
Signed-off-by: NGuangyao Ma <guangyao.ma@outlook.com>

【背景】定期A核代码告警清零。

【修改方案】
根据工具扫描结果，对代码告警进行更改。

【影响】
对现有的产品编译不会有影响。

re #I4378T
Signed-off-by: Nwangchen <253227059@qq.com>

write "clear pathcahe" to clear pathcaches and vnodes
write "clear pagecache" to clear pagecaches
write "clear all" to clear both pathcaches and pagechaches
the cache in use will not be cleared

close: #I3XLPH
Signed-off-by: Nmucor <mucorwang@gmail.com>

add /proc/fs_cache to display vnode, path cache, page cache.
also change some bad virable name

close: #I3WWBD
Signed-off-by: Nmucor <mucorwang@gmail.com>

add /proc/fs_cache to display vnode, path cache, page cache.
also change some bad virable name

close: #I3WESD
Signed-off-by: Nmucor <mucorwang@gmail.com>

1.remove redundant headfile in kernel, such as:
  compiler.h;debug.h;automount.h;inode.h;syslog.h;net.h;
2.split fs.h to file.h and driver.h
3.move vnode.h and path_cache.h to vfs/include
4.remove redundant interface and defines

close: #I3RTNR
Signed-off-by: Nmucor <mucorwang@gmail.com>

1，VFS代码中不修改参数增加const修饰
2，fs_file_mapping.c: 增加安全函数的判空
3，path_cache.c: sizeof改为使用类型
4，fs_syscall.c: 对NULL解引用
5，VnodeLookup：冗余的判空，及不正确的判空

close: I3UMWD
Signed-off-by: yansira <yansira@hotmail.com>

/dev/

fix #I3TS1Y
Signed-off-by: yansira <yansira@hotmail.com>

Change-Id: I2205bbf42e7c2339f81443ace6924b12f4fa1c09

Function VnodeInUseIter and VnodeFreeAll used to be recursive.
Now we traverse the current in-use vnode list to find the vnode in
1 filesystem

Close #I3NN3U

Close: I3NGBT
Change-Id: I70130c42061e51f5978b48befea66a5925386343

Close: I3MZZ6
Change-Id: Iab3919a2eebb44c82531a7fa7a2f688ec4bcc5a0

Close #I3MYP4

Change-Id: I533f4bacaf7e6dd500f5ac3ce4f5343b3b885988

Change-Id: I052d930d54e63179b17b77f02c107a015f3cfc3f

Change-Id: I44981eb9475feb4604ffe91244b4dff00f7d1548

Change-Id: Ia956fd09f1bd734cd26ab631359c1e2131fe1e37

    buginfo: when try to umount a nfs node, it may casue stack overflow.

Change-Id: I7d96f74a770607c990ca5f51cb92fb2843a08d12

Change-Id: Ic443742e125915f0e5332a338dedea5c40348928

Feature or Bugfix:Feature
Binary Source:Huawei
PrivateCode(Yes/No):Yes

Change-Id: I175d2648bc6f9078c34de2c0a5c93fda10b86c47
ChangeID:13306388