On 07/29/2016 03:38 PM, Robert Yang wrote:
On 07/05/2016 09:10 PM, Mark Hatle wrote:
On 7/5/16 5:23 AM, Robert Yang wrote:
Hi,
When run "chmod 0444 <file>" under pseudo, it would always adds
write permission for real file (and w + x for dir), which means that
it runs as "chmod 0644 <file>". It does this on real file, not record
this on pseudo's database. Here are the code from pseudo:
/* Root can read and write files, and enter directories which have no
* read, write, or execute permissions. (But can't execute files without
* execute permissions!)
*
* A non-root user can't.
*
* When doing anything which actually writes to the filesystem, we add in
* the user read/write/execute bits. When storing to the database, though,
* we mask out any such bits which weren't in the original mode.
*/
#define PSEUDO_FS_MODE(mode, isdir) (((mode) | S_IRUSR | S_IWUSR | ((isdir) ?
S_IXUSR : 0)) & ~(S_IWGRP | S_IWOTH))
#define PSEUDO_DB_MODE(fs_mode, user_mode) (((fs_mode) & ~0722) | ((user_mode &
0722)))
It has a side effect for -dbg pkgs if the source files foo.c's mode is 0444:
1) bitbake foo
2) Edit rpm-native
3) bitbake foo
After the first bitake foo, we will see that foo.c in foo-dbg is 0444, but
after the second bitbake foo, foo.c in foo-dbg will be 0644, because the first
build has changed src file foo.c's mode to 0644, this is incorrect.
I have two suggestions on it:
1) Don't add more permissions when chmod(e.g., don't change 0444 -> 0644),
The user can add it clearly if a file/dir really needs that.
As noted above, we have to adjust the permissions to writable, or we can not
make various changes later. When working as the 'root' user, permissions are
basically ignored. So a non-writable file is still writable. The only way to
emulate this is to make the actual file writable.
I don't understand how/why on a second run the 0644 is showing up though.
Hi Mark,
It got 0644 but not 0444 in the second build was because pseudo's unlink
doesn't take core of hard links, for example:
$ umask 0022
$ touch file1
$ ln file1 file2
$ chmod 0777 file1
$ ls -l file1 file2
We can see that both file1 and file2's mode is 0777.
But if we remove file1:
$ rm -f file1
$ ls file2
Now file2's mode is 0644 since the info had been removed from database.
After talked with RP online, there isn't any file systems that can support
different modes on different references for the same inode, so pseudo's
Here should be: "there isn't any file systems can ... *as far as we know*"
// Robert
chmod should update all the references' mode, in another word, it should
not remove the info from database if links count is greater than 1.
Here is a patch for pseudo to fix the problem, I'm testing it locally now,
will send out sooner:
diff --git a/ports/unix/guts/unlinkat.c b/ports/unix/guts/unlinkat.c
index e723a01..a0ff685 100644
--- a/ports/unix/guts/unlinkat.c
+++ b/ports/unix/guts/unlinkat.c
@@ -36,8 +36,9 @@
if (rc == -1) {
return rc;
}
+
msg = pseudo_client_op(OP_MAY_UNLINK, 0, -1, dirfd, path, &buf);
- if (msg && msg->result == RESULT_SUCCEED)
+ if (msg && msg->result == RESULT_SUCCEED && buf.st_nlink == 1)
old_db_entry = 1;
#ifdef PSEUDO_NO_REAL_AT_FUNCTIONS
rc = real_unlink(path);
@@ -52,6 +53,8 @@
} else {
pseudo_client_op(OP_DID_UNLINK, 0, -1, -1, path, &buf);
}
+ } else if (buf.st_nlink > 1) {
+ pseudo_debug(PDBGF_FILE, "not remove ino %lu from database since its
links count is greater than 1.\n", buf.st_ino);
} else {
pseudo_debug(PDBGF_FILE, "unlink on <%s>, not in database, no
effect.\n", path);
}
// Robert
Unless the pseudo database is wiped -- or the debug commands are not clearing
the split directories before writing into them, it should be creating new files
with the new pseudo database that follows the same semantics.
2) This mainly affects do_package task AFAIK, the code is:
if not cpath.islink(file):
os.link(file, fpath)
fstat = cpath.stat(file)
os.chmod(fpath, fstat.st_mode)
os.chown(fpath, fstat.st_uid, fstat.st_gid)
Another solution is checking mode before run chmod, if we really need
run chmod, then copy the file rather than link.
Any suggestion is appreciated.
The following recipes in oe-core have this issue:
blktool
coreutils
e2fsprogs
gnutls
guile
gzip
less
lsof
mtools
opensp
parted
screen
tcp-wrappers
--
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