rsync - Mar 2014 - [Bug 10494] New: remove-source-files fails with symlinks

https://bugzilla.samba.org/show_bug.cgi?id=10494

           Summary: remove-source-files fails with symlinks
           Product: rsync
           Version: 3.1.0
          Platform: x64
        OS/Version: Linux
            Status: NEW
          Severity: major
          Priority: P5
         Component: core
        AssignedTo: wayned at samba.org
        ReportedBy: afried at deteque.com
         QAContact: rsync-qa at samba.org


Up thru 3.0.9 transferring symlinks using "-L --remove-source-files"
properly
transferred the files and removed the symlinks.

Beginning with 3.1.0 this no longer works; the files transfer properly but the
symlinks on the source server fail to get deleted. This error message is
displayed:

ERROR: Skipping sender remove for changed file: [transferred file name]

I have not been able to find a workaround to this problem, other than
downgrading from 3.1.0 back to 3.0.9.

-- 
Configure bugmail: https://bugzilla.samba.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.

https://bugzilla.samba.org/show_bug.cgi?id=10494

Wayne Davison <wayned at samba.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #1 from Wayne Davison <wayned at samba.org> ---
That's weird, as it means that the source symlink must differ in size or
modify
time from what rsync put into the source file list.  However, since that safety
check is only really needed for regular files, I've added some code that
should
avoid this failure for symlinks and devices.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.

https://bugzilla.samba.org/show_bug.cgi?id=10494

--- Comment #2 from Adrian Torregrosa <adrian.torregrosa.ext at nokia.com>
---
We have found this same problem using rsync 3.1.2.

I have downloaded the source code for version 3.1.3, and found the following
lines in sender.c:

146         if (S_ISREG(file->mode) /* Symlinks & devices don't need
this
check: */
147          && (st.st_size != F_LENGTH(file) || st.st_mtime !=
file->modtime
148 #ifdef ST_MTIME_NSEC
149          || (NSEC_BUMP(file) && (uint32)st.ST_MTIME_NSEC
!F_MOD_NSEC(file))
150 #endif
151         )) {
152                 rprintf(FERROR_XFER, "ERROR: Skipping sender remove for
changed file: %s\n", fname);
153                 return;
154         }

I added some debugging info, compiled and tested, and found out that when
trying to retrieve symlinks the "file" pointer refers to the hard
file, whereas
the "st" register refers to the symlink. Therefore
"S_ISREG(file->mode)" will
be true, so will be "st.st_size != F_LENGTH(file)" and most likely
"st.st_mtime
!= file->modtime" too. As a result the error gets printed and the
symlink is
not deleted, as intended.

I have tried modifying the first condition and it worked as expected:
146         if (S_ISREG(st.st_mode) /* Symlinks & devices don't need
this
check: */

Best regards.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.

https://bugzilla.samba.org/show_bug.cgi?id=10494

--- Comment #3 from Adrian Torregrosa <adrian.torregrosa.ext at nokia.com>
---
Another option that I tried and verified, and that could make more sense, would
be to replace

141         if (do_lstat(fname, &st) < 0) {

with

141         if (do_stat(fname, &st) < 0) {

-- 
You are receiving this mail because:
You are the QA Contact for the bug.

https://bugzilla.samba.org/show_bug.cgi?id=10494

--- Comment #4 from Wayne Davison <wayne at opencoder.net> ---
In my prior testing I apparently missed that the symlink verification issue was
caused by -L (--copy-links).  I have amended the change to use do_stat() when
--copy-links is enabled.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.

https://bugzilla.samba.org/show_bug.cgi?id=10494

--- Comment #5 from Adrian Torregrosa <adrian.torregrosa.ext at nokia.com>
---
I embedded the modified sender.c into 3.1.3's original source code, compiled
and tested, and I found it to have solved the problem: first I tried uploading
a softlink and deleting, then I tried uploading a normal file and deleting. It
worked the two times.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.