[PATCH 04/18] fs: implement stat

[Jean-Christophe PLAGNIOL-VILLARD]

On 15:52 Mon 27 Aug     , Sascha Hauer wrote:
> On Fri, Aug 24, 2012 at 06:50:04AM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > stat() stats the file pointed to by path and fills in buf.
> > 
> > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> > ---
> >  fs/fs.c      |  102 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  include/fs.h |    6 ++--
> >  2 files changed, 104 insertions(+), 4 deletions(-)
> > 
> > diff --git a/fs/fs.c b/fs/fs.c
> > index a19e1f4..9f2e82c 100644
> > --- a/fs/fs.c
> > +++ b/fs/fs.c
> > @@ -26,6 +26,7 @@
> >  #include <errno.h>
> >  #include <malloc.h>
> >  #include <linux/stat.h>
> > +#include <linux/err.h>
> >  #include <fcntl.h>
> >  #include <xfuncs.h>
> >  #include <init.h>
> > @@ -111,6 +112,60 @@ static int init_cwd(void)
> >  
> >  postcore_initcall(init_cwd);
> >  
> > +char *normalise_link(const char *pathname, const char* symlink)
> 
> like this instead: const char *symlink
> 
> > +{
> > +	const char *buf = symlink;
> > +	char *path_free, *path;
> > +	char *absolute_path;
> > +	int point = 0;
> > +	int dir = 1;
> > +	int len;
> > +
> > +	if (symlink[0] == '/')
> > +		return strdup(symlink);
> > +
> > +	path = path_free = strdup(pathname);
> > +
> > +	while (*buf == '.' || *buf == '/') {
> > +		if (*buf == '.') {
> > +			point++;
> > +		} else if (*buf == '/') {
> > +			point = 0;
> > +			dir++;
> > +		}
> > +		if (point > 2) {
> > +			buf -= 2;
> > +			break;
> > +		}
> > +		buf++;
> > +	}
> > +
> > +	if (dir) {
> 
> This is always true. Even if not, this would be covered by while (dir)
> below.
> 
> > +		while(dir) {
> > +			path = dirname(path);
> > +			dir--;
> > +		}
> > +	}
> > +
> > +	len = strlen(buf) + strlen(path) + 1;
> > +	if (buf[0] != '/')
> > +		len++;
> > +
> > +	absolute_path = calloc(sizeof(char), len);
> > +
> > +	if(!absolute_path)
> 
> if (
> 
> > +		return NULL;
> > +
> > +	strcat(absolute_path, path);
> > +	if (buf[0] != '/')
> > +		strcat(absolute_path, "/");
> > +	strcat(absolute_path, buf);
> > +
> > +	free(path_free);
> > +
> > +	return absolute_path;
> > +}
> > +
> >  char *normalise_path(const char *pathname)
> >  {
> >  	char *path = xzalloc(strlen(pathname) + strlen(cwd) + 2);
> > @@ -512,6 +567,40 @@ out:
> >  }
> >  EXPORT_SYMBOL(unlink);
> >  
> > +static char* realfile(const char *pathname, struct stat *s)
> 
> static char *realfile
> 
> > +{
> > +	char *path = normalise_path(pathname);
> > +	int ret;
> > +
> > +	ret = lstat(path, s);
> > +	if (ret)
> > +		goto out;
> > +
> > +	if (S_ISLNK(s->st_mode)) {
> > +		char tmp[PATH_MAX];
> > +		char *new_path;
> > +
> > +		ret = readlink(path, tmp, PATH_MAX);
> > +		if (ret < 0)
> > +			goto out;
> > +
> > +		new_path = normalise_link(path, tmp);
> > +		free(path);
> > +		if (!new_path)
> > +			return ERR_PTR(-ENOMEM);
> > +		path = new_path;
> > +
> > +		ret = lstat(path, s);
> > +	}
> 
> I see no code handling multiple link levels. I think this should be
> here?
yeap I did not add it so far I plan to add it in a second step if we need it
so far I'm not really sure

Best Regards,
J.