Hi Ted, (2010/01/16 15:29), tytso@xxxxxxx wrote: > On Fri, Jan 15, 2010 at 07:11:28PM +0530, SandeepKsinha wrote: >>>> I found your comment about ext4 online defrag on Ubuntu BBS by accident. >>>> https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/321528 >>>> >>>> I would like to address this problem so I ran e4defrag on the system >>>> which was under memory pressure. But unfortunately I could not find the bug. >>>> If you have already known how to reproduce this kind of problem, >>>> could you teach me how? > > I'm sorry I wasn't clear. I don't know of any specific problem with > the code, but I and some other ext4 developers remain a bit conerned > about the code because of how it is structured, and the fact that > there is so much code and there hasn't been a lot of people spent a > lot of time going through it and cleaning it up. We also don't have > good regression tests for the kernel defrag support code. > > This is partially my fault; I haven't had enough time to do more > testing and code clean up on the defrag code. I need to spend more > time doing some testing and code cleanup before I'll be comfortable > telling people that it is as reliable as other parts of ext4 in terms > of not potentially losing their data. Maybe it's just my paranoia.... > All right. I have already fixed all reported bugs so far, but I recognize that e4defrag needs more tests and review, so I will continue testing. BTW, I would like to ask you about e4defrag command merge plan. The following e4defrag patches have been released. How are you going to do these patches in future? 1: From Kazuya Mio <k-mio@xxxxxxxxxxxxx> [RFC][PATCH v2 1/4] e4defrag: output size per extent by -c option http://marc.info/?l=linux-ext4&m=125602666514382&w=4 2: From Kazuya Mio <k-mio@xxxxxxxxxxxxx> [RFC][PATCH v2 2/4] e4defrag: fix file blocks calculation http://marc.info/?l=linux-ext4&m=125602676114522&w=4 3: From Kazuya Mio <k-mio@xxxxxxxxxxxxx> [RFC][PATCH v2 3/4] e4defrag: avoid unsuccessful return in non-privileged http://marc.info/?l=linux-ext4&m=125602682614647&w=4 4: From Kazuya Mio <k-mio@xxxxxxxxxxxxx> [RFC][PATCH v2 4/4] e4defrag: update man page about -c option http://marc.info/?l=linux-ext4&m=125602694414881&w=4 5: From Eric Sandeen <sandeen@xxxxxxxxxx> [PATCH] Skip "rootfs" entry when checking for ext4 filesystem. http://marc.info/?l=linux-ext4&m=125242643605387&w=4 6: From Akira Fujita <a-fujita@xxxxxxxxxxxxx> [PATCH 2/2]e4defrag: Fix open flag for original file # I sent this patch to you on December 3th personally, it's not in the linux-ext4 so I attach it in below. Manish also send same patch. Regards, Akira Fujita e4defrag: Fix open flag for original file From: Akira Fujita <a-fujita@xxxxxxxxxxxxx> e4defrag command uses EXT4_IOC_MOVE_EXT to exchange blocks between original and donor files. And there is a read/write access check for original file in kernel-space, so open it with RDWR flag in user-space. Signed-off-by: Akira Fujita <a-fujita@xxxxxxxxxxxxx> --- misc/e4defrag.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/misc/e4defrag.c b/misc/e4defrag.c index 82e3868..424e0ca 100644 --- a/misc/e4defrag.c +++ b/misc/e4defrag.c @@ -1605,7 +1605,7 @@ static int file_defrag(const char *file, const struct stat64 *buf, return 0; } - fd = open64(file, O_RDONLY); + fd = open64(file, O_RDWR); if (fd < 0) { if (mode_flag & DETAIL) { PRINT_FILE_NAME(file); -- 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
