* Re: [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 [not found] <19860.58082.277944.875401@gargle.gargle.HOWL> @ 2011-04-01 7:46 ` Aneesh Kumar K. V 2011-04-01 8:45 ` Miklos Szeredi 2011-04-05 12:23 ` Karel Zak 0 siblings, 2 replies; 6+ messages in thread From: Aneesh Kumar K. V @ 2011-04-01 7:46 UTC (permalink / raw) To: victor.vde, util-linux, Miklos Szeredi, linuxram Cc: Alexander Viro, Victor van den Elzen, Eugene J. Markow, linux-fsdevel, linux-kernel On Thu, 31 Mar 2011 22:24:01 +0200, victor.vde@gmail.com wrote: > /proc/self/mountinfo on Linux v2.6.39-rc1 includes the UUID of ext4 > and ext3 mounts, for example: > > 15 1 8:3 / / rw,noatime uuid:c645234d-9756-4d84-825e-6fe999252a34 - ext4 /dev/sda3 rw,user_xattr,acl,barrier=1,data=ordered > > It seems the hyphens in the uuid confuse the parser > mnt_parse_mountinfo_line in tab_parse.c of libmount in util-linux. shouldn't the parser look for " " followed by "-" followed by " " as the field seperator ? I am adding Miklos and Ram Pai to CC to check whether the kernel or the libmount should be fixed ? > > My util-linux version is 2.19-4 Arch Linux. > > ~ $ findmnt -l / > TARGET SOURCE FSTYPE OPTIONS > / - 9756-4d84-825e-6fe999252a34 rw,noatime,ext4 > > For reference, the commits in Linus' tree that introduced these uuids > are: > > 93f1c20bc8cdb757be50566eff88d65c3b26881f vfs: Export file system uuid via /proc/<pid>/mountinfo > 03cb5f03dcb26846fcad345d8c15aae91579a53d ext3: Copy fs UUID to superblock. > f2fa2ffc2046fdc35f96366d1ec8675f4d578522 ext4: Copy fs UUID to superblock -aneesh ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 2011-04-01 7:46 ` [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 Aneesh Kumar K. V @ 2011-04-01 8:45 ` Miklos Szeredi 2011-04-01 9:32 ` Karel Zak 2011-04-05 12:23 ` Karel Zak 1 sibling, 1 reply; 6+ messages in thread From: Miklos Szeredi @ 2011-04-01 8:45 UTC (permalink / raw) To: Aneesh Kumar K. V Cc: victor.vde, util-linux, miklos, linuxram, viro, victor.vde, ejmarkow, linux-fsdevel, linux-kernel On Fri, 01 Apr 2011, Aneesh Kumar K. V wrote: > On Thu, 31 Mar 2011 22:24:01 +0200, victor.vde@gmail.com wrote: > > /proc/self/mountinfo on Linux v2.6.39-rc1 includes the UUID of ext4 > > and ext3 mounts, for example: > > > > 15 1 8:3 / / rw,noatime uuid:c645234d-9756-4d84-825e-6fe999252a34 - ext4 /dev/sda3 rw,user_xattr,acl,barrier=1,data=ordered > > > > It seems the hyphens in the uuid confuse the parser > > mnt_parse_mountinfo_line in tab_parse.c of libmount in util-linux. > > shouldn't the parser look for " " followed by "-" followed by " " as the > field seperator ? > > I am adding Miklos and Ram Pai to CC to check whether the kernel or the libmount > should be fixed ? I think libmount should be fixed, though there is always the question of backward compatibility. However I don't see how the kernel could be fixed, given that libmount doesn't seem to parse escape sequences (e.g. "\040" for space), which it also should. Karel? Thanks, Miklos ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 2011-04-01 8:45 ` Miklos Szeredi @ 2011-04-01 9:32 ` Karel Zak [not found] ` <20110401093240.GA11012-sHeGUpI7y9L/9pzu0YdTqQ@public.gmane.org> 0 siblings, 1 reply; 6+ messages in thread From: Karel Zak @ 2011-04-01 9:32 UTC (permalink / raw) To: Miklos Szeredi Cc: Aneesh Kumar K. V, victor.vde, util-linux, linuxram, viro, ejmarkow, linux-fsdevel, linux-kernel, Lennart Poettering On Fri, Apr 01, 2011 at 10:45:48AM +0200, Miklos Szeredi wrote: > On Fri, 01 Apr 2011, Aneesh Kumar K. V wrote: > > On Thu, 31 Mar 2011 22:24:01 +0200, victor.vde@gmail.com wrote: > > > /proc/self/mountinfo on Linux v2.6.39-rc1 includes the UUID of ext4 > > > and ext3 mounts, for example: > > > > > > 15 1 8:3 / / rw,noatime uuid:c645234d-9756-4d84-825e-6fe999252a34 - ext4 /dev/sda3 rw,user_xattr,acl,barrier=1,data=ordered > > > > > > It seems the hyphens in the uuid confuse the parser > > > mnt_parse_mountinfo_line in tab_parse.c of libmount in util-linux. > > > > shouldn't the parser look for " " followed by "-" followed by " " as the > > field seperator ? > > > > I am adding Miklos and Ram Pai to CC to check whether the kernel or the libmount > > should be fixed ? > > I think libmount should be fixed, though there is always the question > of backward compatibility. The parser uses rc = sscanf(s, "%u " /* (1) id */ "%u " /* (2) parent */ "%u:%u " /* (3) maj:min */ "%ms " /* (4) mountroot */ "%ms " /* (5) target */ "%ms" /* (6) vfs options (fs-independent) */ "%*[^-]" /* (7) optional fields */ "- " /* (8) separator */ "%ms " /* (9) FS type */ "%ms " /* (10) source */ "%ms", /* (11) fs options (fs specific) */ note that almost the same code is in systemd. > However I don't see how the kernel could be fixed, given that libmount > doesn't seem to parse escape sequences (e.g. "\040" for space), which > it also should. It calls unmangle_string() for all fields, so all sequences should be decoded. Karel -- Karel Zak <kzak@redhat.com> http://karelzak.blogspot.com ^ permalink raw reply [flat|nested] 6+ messages in thread
[parent not found: <20110401093240.GA11012-sHeGUpI7y9L/9pzu0YdTqQ@public.gmane.org>]
* Re: [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 [not found] ` <20110401093240.GA11012-sHeGUpI7y9L/9pzu0YdTqQ@public.gmane.org> @ 2011-04-01 10:12 ` Miklos Szeredi 2011-04-01 10:38 ` Karel Zak 0 siblings, 1 reply; 6+ messages in thread From: Miklos Szeredi @ 2011-04-01 10:12 UTC (permalink / raw) To: Karel Zak Cc: miklos-sUDqSbJrdHQHWmgEVkV9KA, aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8, victor.vde-Re5JQEeQqe8AvxtiuMwx3w, util-linux-u79uwXL29TY76Z2rM5mHXA, linuxram-r/Jw6+rmf7HQT0dZR+AlfA, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn, ejmarkow-/E1597aS9LQAvxtiuMwx3w, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, linux-kernel-u79uwXL29TY76Z2rM5mHXA, lennart-mdGvqq1h2p+GdvJs77BJ7Q On Fri, 1 Apr 2011, Karel Zak wrote: > On Fri, Apr 01, 2011 at 10:45:48AM +0200, Miklos Szeredi wrote: > > On Fri, 01 Apr 2011, Aneesh Kumar K. V wrote: > > > On Thu, 31 Mar 2011 22:24:01 +0200, victor.vde-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote: > > > > /proc/self/mountinfo on Linux v2.6.39-rc1 includes the UUID of ext4 > > > > and ext3 mounts, for example: > > > > > > > > 15 1 8:3 / / rw,noatime uuid:c645234d-9756-4d84-825e-6fe999252a34 - ext4 /dev/sda3 rw,user_xattr,acl,barrier=1,data=ordered > > > > > > > > It seems the hyphens in the uuid confuse the parser > > > > mnt_parse_mountinfo_line in tab_parse.c of libmount in util-linux. > > > > > > shouldn't the parser look for " " followed by "-" followed by " " as the > > > field seperator ? > > > > > > I am adding Miklos and Ram Pai to CC to check whether the kernel or the libmount > > > should be fixed ? > > > > I think libmount should be fixed, though there is always the question > > of backward compatibility. > > The parser uses > > rc = sscanf(s, "%u " /* (1) id */ > "%u " /* (2) parent */ > "%u:%u " /* (3) maj:min */ > "%ms " /* (4) mountroot */ > "%ms " /* (5) target */ > "%ms" /* (6) vfs options (fs-independent) */ > "%*[^-]" /* (7) optional fields */ So this says, "skip everything up to the first hyphen", even though the rule might be better expressed as "skip all space delimited words up to the first standalone hyphen". I guess that's not possible to express with a scanf expression, though. > "- " /* (8) separator */ > "%ms " /* (9) FS type */ > "%ms " /* (10) source */ > "%ms", /* (11) fs options (fs specific) */ > > note that almost the same code is in systemd. > > > However I don't see how the kernel could be fixed, given that libmount > > doesn't seem to parse escape sequences (e.g. "\040" for space), which > > it also should. > > It calls unmangle_string() for all fields, so all sequences should be > decoded. Okay, so the kernel can simply escape the troublesome hyphens, which would make the human parsing of /proc/pid/mountinfo more difficult but at least would fix compatibility with util-linux's parser. Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 2011-04-01 10:12 ` Miklos Szeredi @ 2011-04-01 10:38 ` Karel Zak 0 siblings, 0 replies; 6+ messages in thread From: Karel Zak @ 2011-04-01 10:38 UTC (permalink / raw) To: Miklos Szeredi Cc: aneesh.kumar, victor.vde, util-linux, linuxram, viro, ejmarkow, linux-fsdevel, linux-kernel, lennart On Fri, Apr 01, 2011 at 12:12:34PM +0200, Miklos Szeredi wrote: > On Fri, 1 Apr 2011, Karel Zak wrote: > > On Fri, Apr 01, 2011 at 10:45:48AM +0200, Miklos Szeredi wrote: > > > On Fri, 01 Apr 2011, Aneesh Kumar K. V wrote: > > > > On Thu, 31 Mar 2011 22:24:01 +0200, victor.vde@gmail.com wrote: > > > > > /proc/self/mountinfo on Linux v2.6.39-rc1 includes the UUID of ext4 > > > > > and ext3 mounts, for example: > > > > > > > > > > 15 1 8:3 / / rw,noatime uuid:c645234d-9756-4d84-825e-6fe999252a34 - ext4 /dev/sda3 rw,user_xattr,acl,barrier=1,data=ordered > > > > > > > > > > It seems the hyphens in the uuid confuse the parser > > > > > mnt_parse_mountinfo_line in tab_parse.c of libmount in util-linux. > > > > > > > > shouldn't the parser look for " " followed by "-" followed by " " as the > > > > field seperator ? > > > > > > > > I am adding Miklos and Ram Pai to CC to check whether the kernel or the libmount > > > > should be fixed ? > > > > > > I think libmount should be fixed, though there is always the question > > > of backward compatibility. > > > > The parser uses > > > > rc = sscanf(s, "%u " /* (1) id */ > > "%u " /* (2) parent */ > > "%u:%u " /* (3) maj:min */ > > "%ms " /* (4) mountroot */ > > "%ms " /* (5) target */ > > "%ms" /* (6) vfs options (fs-independent) */ > > "%*[^-]" /* (7) optional fields */ > > So this says, "skip everything up to the first hyphen", even though > the rule might be better expressed as "skip all space delimited words > up to the first standalone hyphen". I guess that's not possible to > express with a scanf expression, though. Yes, I'll probably use two sscanf(), %n and strstr(), something like: rc = sscanf(s, "%u " /* (1) id */ "%u " /* (2) parent */ "%u:%u " /* (3) maj:min */ "%ms " /* (4) mountroot */ "%ms " /* (5) target */ "%ms" /* (6) vfs options (fs-independent) */ "%n", &id, &parent, &maj, &min, &root, &target, &vfs_optstr, &end); s += end; /* (7) optional fields, terminated by " - " */ p = strstr(s, " - "); if (p) s = p + 3; rc += sscanf(s, "%ms " /* (8) FS type */ "%ms " /* (9) source */ "%ms", /* (10) fs options (fs specific) */ &fstype, &src, &fs_optstr); ...or anyone has a better idea? > > It calls unmangle_string() for all fields, so all sequences should be > > decoded. > > Okay, so the kernel can simply escape the troublesome hyphens, which > would make the human parsing of /proc/pid/mountinfo more difficult but > at least would fix compatibility with util-linux's parser. Hmm.. IMHO it will be better to fix the parsers in libmount and systemd. The both projects are young, nobody will be surprised with bugs :-) I think the example in Documentation/filesystems/proc.txt is pretty obvious, the separator is an extra field with " - ". Karel -- Karel Zak <kzak@redhat.com> http://karelzak.blogspot.com ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 2011-04-01 7:46 ` [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 Aneesh Kumar K. V 2011-04-01 8:45 ` Miklos Szeredi @ 2011-04-05 12:23 ` Karel Zak 1 sibling, 0 replies; 6+ messages in thread From: Karel Zak @ 2011-04-05 12:23 UTC (permalink / raw) To: Aneesh Kumar K. V Cc: victor.vde, util-linux, Miklos Szeredi, linuxram, Alexander Viro, Eugene J. Markow, linux-fsdevel, linux-kernel On Fri, Apr 01, 2011 at 01:16:23PM +0530, Aneesh Kumar K. V wrote: > On Thu, 31 Mar 2011 22:24:01 +0200, victor.vde@gmail.com wrote: > > /proc/self/mountinfo on Linux v2.6.39-rc1 includes the UUID of ext4 > > and ext3 mounts, for example: > > > > 15 1 8:3 / / rw,noatime uuid:c645234d-9756-4d84-825e-6fe999252a34 - ext4 /dev/sda3 rw,user_xattr,acl,barrier=1,data=ordered > > > > It seems the hyphens in the uuid confuse the parser > > mnt_parse_mountinfo_line in tab_parse.c of libmount in util-linux. > > shouldn't the parser look for " " followed by "-" followed by " " as the > field seperator ? > > I am adding Miklos and Ram Pai to CC to check whether the kernel or the libmount > should be fixed ? The libmount (in util-linux git tree) should be fixed now. Thanks for the report! Karel -- Karel Zak <kzak@redhat.com> http://karelzak.blogspot.com ^ permalink raw reply [flat|nested] 6+ messages in thread
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2011-04-01 7:46 ` [BUG] libmount misparses mountinfo on Linux v2.6.39-rc1 Aneesh Kumar K. V
2011-04-01 8:45 ` Miklos Szeredi
2011-04-01 9:32 ` Karel Zak
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2011-04-01 10:12 ` Miklos Szeredi
2011-04-01 10:38 ` Karel Zak
2011-04-05 12:23 ` Karel Zak
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