On Fri, Sep 21, 2012 at 10:21:00PM -0300, Herton Ronaldo Krzesinski wrote: > There is no reason to use static there, and it will cause issues when > reading /proc/fs/ext4/<partition>/options concurrently. > > Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx # 3.4+ Herton, Thanks for finding the bug fix! I changed the commit descipription slightly and have applied your patch to the ext4 tree. - Ted ext4: fix crash when accessing /proc/mounts concurrently From: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx> The crash was caused by a variable being erronously declared static in token2str(). In addition to /proc/mounts, the problem can also be easily replicated by accessing /proc/fs/ext4/<partition>/options in parallel: $ cat /proc/fs/ext4/<partition>/options > options.txt ... and then running the following command in two different terminals: $ while diff /proc/fs/ext4/<partition>/options options.txt; do true; done This is also the cause of the following a crash while running xfstests #234, as reported in the following bug reports: https://bugs.launchpad.net/bugs/1053019 https://bugzilla.kernel.org/show_bug.cgi?id=47731 Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> Cc: Brad Figg <brad.figg@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
