Hi Jan, On Tue, 2010-05-11 at 18:24 +0200, Jan Kara wrote: > On Tue 11-05-10 17:48:51, Jan Kara wrote: > > On Thu 06-05-10 14:30:02, Andrew Morton wrote: > > > > > > (switched to email. Please respond via emailed reply-to-all, not > via the > > > bugzilla web interface). > > > > > > On Wed, 5 May 2010 13:01:22 GMT > > > bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > > > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=15909 > > > > > > > > Summary: open("a/",O_NOFOLLOW) fails with ELOOP if > "a" is a > > > > symbolic link to a directory. > > > > Product: File System > > > > Version: 2.5 > > > > Kernel Version: 2.6.34-rc6 > > > > Platform: All > > > > OS/Version: Linux > > > > Tree: Mainline > > > > Status: NEW > > > > Severity: high > > > > Priority: P1 > > > > Component: Other > > > > AssignedTo: fs_other@xxxxxxxxxxxxxxxxxxxx > > > > ReportedBy: tolzmann@xxxxxxxxxxxxx > > > > Regression: No > > > > > > > > > > > > mkdir c > > > > ln -s c a > > > > > > > > f=open("a/",O_RDONLY+O_NOFOLLOW) > > > > > > > > fails with ELOOP. However, this open should behave like > open("a/.") not like > > > > open("a") according to path_resolution(7). In kernel version > 2.6.32 the open > > > > worked as documented. > > > > > > > > On a higher level this bug makes > > > > > > > > find a/ > > > > > > > > to fail. > > > > > > > > > > It sounds like this 2.6.32->2.6.34-rc6 regression could have > pretty > > > serious ramifications for some users. Does anyone know whcih > commit > > > might have caused it? > > The patch below fixes the issue for me but someone should have a > look > > at it because I'm not really an expert in that code and the code > paths are so > > twisted that my mind is currently tied into a knot ;). > > > > Honza > > --- > > > > From d53d3cc6488d9135bb69c3ff7e034b3b624866ed Mon Sep 17 00:00:00 > 2001 > > From: Jan Kara <jack@xxxxxxx> > > Date: Tue, 11 May 2010 16:34:25 +0200 > > Subject: [PATCH] vfs: Fix O_NOFOLLOW behavior for paths with > trailing slashes > > > > According to specification > > mkdir d; ln -s d a; open("a/", O_NOFOLLOW | O_RDONLY) > > should return success but currently it did return ELOOP. Fix the > code to ignore > > O_NOFOLLOW in case the provided path has trailing slashes. This is a > regression > > caused by path lookup cleanup patch series. > > > > CC: stable@xxxxxxxxxx > > Signed-off-by: Jan Kara <jack@xxxxxxx> > ... > BTW: It might be worthwhile to add the attached testcase to LTP? It would be great if you can shoot it in the form of a patch, mentioning 1. The GPL Lincense, 2. The purpose of the test case, 3. Exact location it goes, 4. Which LTPROOT/runtest/<file> executes it Regards-- Subrata :-) > > Honza > -- > Jan Kara <jack@xxxxxxx> > SUSE Labs, CR > > > > > > > > C++ source code > attachment > (open-follow-test.c) > > #define _GNU_SOURCE > #include <stdio.h> > #include <unistd.h> > #include <fcntl.h> > #include <errno.h> > #include <string.h> > #include <sys/stat.h> > #include <sys/types.h> > > int do_test(char *p) > { > int err; > char path[16]; > > strcpy(path, p); > err = open(path, O_NOFOLLOW | O_RDONLY); > if (err >= 0) { > fprintf(stderr, "open(\"%s\", O_NOFOLLOW | O_RDONLY) did not fail! > \n", path); > return 1; > } > strcat(path, "/"); > err = open(path, O_NOFOLLOW | O_RDONLY); > if (err < 0) { > fprintf(stderr, "open(\"%s\", O_NOFOLLOW | O_RDONLY) failed with % > d\n", path, errno); > return 1; > } > strcat(path, "."); > err = open(path, O_NOFOLLOW | O_RDONLY); > if (err < 0) { > fprintf(stderr, "open(\"%s\", O_NOFOLLOW | O_RDONLY) failed with % > d\n", path, errno); > return 1; > } > return 0; > } > > int main(void) > { > if (mkdir("d", 0700) < 0) { > perror("mkdir"); > return 1; > } > if (symlink("d", "a") < 0) { > perror("link"); > return 1; > } > if (do_test("a")) > return 1; > return 0; > } -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
