Hi, Akira, Akira Fujita wrote: > Hi Peng, > Peng Tao wrote: >> Hi, Greg, >> >> On Thu, Sep 3, 2009 at 4:59 AM, Greg Freemyer<greg.freemyer@xxxxxxxxx> wrote: >>> Peng, >>> >>> I have not looked at the code very closely, but can you tell me where >>> a file corruption can take place? Not completing the replacement of >>> extents with donor extents is one thing. Corrupting the original file >>> contents is another. >> The file corruption is mainly because of the half done replacement. >> >> My test case is here: >> http://marc.info/?l=linux-ext4&m=124992522305319&w=2 >> > > This patch solves your test case problem. > >> $dd if=/dev/zero of=zero.img bs=10M count=0 seek=50 >> $dd if=../609xp.img of=first.img bs=10M count=1 >> $dd if=/dev/zero of=first.img bs=10M count=0 seek=50 >> $dd if=../609xp.img of=last.img bs=10M count=1 seek=49 >> $dd if=../609xp.img of=middle.img bs=10M count=1 seek=24 >> $dd if=/dev/zero of=middle.img bs=10M count=0 seek=50 > > > This problem is caused by the fact that logical offset of > orig file is different from donor file's. > To detect the logical offset difference in EXT4_IOC_MOVE_EXT, > add checks to mext_calc_swap_extents() and handles it as error, > since data exchange must be done between the same blocks. > > Note: This problem does not happen in ext4 online defrag > (means with e4defrag command), because the donor file > which is created by e4defrag in user space is > file constitution same as orig file. > > And add the extent null check to ext_get_path() for > followings test case. >> $dd if=/dev/zero of=zero.img bs=10M count=0 seek=50 > > More test cases are needed for EXT4_IOC_MOVE_EXT, > so this patch may not be complete, > but the problem you reported is fixed at least. > I am now testing EXT4_IOC_MOVE_EXT hard. > > BTW, I'm now looking into the empty extent issue which > you reported, so I will release the patch soon. > http://marc.info/?l=linux-ext4&m=124975192830024&w=2 > > Could you do your test case again with this patch? After applying the two patches, I run my test case with first.img as the orig file (and middle.img or last.img as donor file). My kernel panics and I find following message in /var/log/messages after reboot: Sep 4 23:21:05 bergwolf -- MARK -- [ 3183.602852] Modules linked in: ext4 ppdev lp parport binfmt_misc i915 kvm_intel kvm uinput ipv6 cpufreq_userspace cpufreq_conservative cpufreq_powersave jbd2 crc16 fuse dm_snapshot dm_mirror dm_region_hash dm_log dm_mod zlib_deflate crc32c acpi_cpufreq sbp2 snd_hda_codec_analog snd_hda_intel snd_hda_codec snd_pcm_oss snd_mixer_oss pcmcia rtc_cmos snd_pcm rtc_core i2c_i801 rtc_lib snd_timer snd_page_alloc psmouse yenta_socket rsrc_nonstatic thinkpad_acpi pcmcia_core serio_raw evdev uhci_hcd firewire_ohci firewire_core crc_itu_t video output ehci_hcd e1000e usbcore [last unloaded: ext4] [ 3183.602951] [ 3183.602958] Pid: 6937, comm: a.out Not tainted (2.6.31-rc2-drm-intel-next #2) 7676A26 [ 3183.602965] EIP: 0060:[<c01cfa26>] EFLAGS: 00210287 CPU: 1 [ 3183.602977] EIP is at journal_start+0x39/0xb9 [ 3183.602982] EAX: f61a2a80 EBX: f26f048c ECX: f6995200 EDX: f6995000 [ 3183.602988] ESI: f26f048c EDI: f6f59c88 EBP: f1a77c90 ESP: f1a77c7c [ 3183.602994] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 3183.603010] 00000002 f6995000 f6f59c88 f26f048c f6f59c88 f1a77c98 c01c9cc6 f1a77cac [ 3183.603024] <0> c01c0b51 f6f59c88 00000001 f6995200 f1a77cc0 c0192799 004cba00 f6f59c88 [ 3183.603039] <0> f68b3840 f1a77cd4 c018ab14 004cba00 00000000 ff7fc000 f1a77d44 c015c7ec [ 3183.603070] [<c01c9cc6>] ? ext3_journal_start_sb+0x40/0x42 [ 3183.603076] [<c01c0b51>] ? ext3_dirty_inode+0x24/0x67 [ 3183.603087] [<c0192799>] ? __mark_inode_dirty+0x23/0xc6 [ 3183.603097] [<c018ab14>] ? file_update_time+0x7a/0xa3 [ 3183.603108] [<c015c7ec>] ? __generic_file_aio_write_nolock+0x2d6/0x3fe [ 3183.603151] [<fa29d3b4>] ? ext4_ext_find_extent+0x3f/0x230 [ext4] [ 3183.603161] [<c015d0e3>] ? generic_file_aio_write+0x57/0xb4 [ 3183.603200] [<fa2a6c26>] ? mext_replace_branches+0x31f/0x329 [ext4] [ 3183.603209] [<c01bef56>] ? ext3_file_write+0x1a/0x88 [ 3183.603219] [<c017b6e2>] ? do_sync_write+0xab/0xe9 [ 3183.603229] [<c0137403>] ? autoremove_wake_function+0x0/0x33 [ 3183.603239] [<c013dbda>] ? getnstimeofday+0x52/0xda [ 3183.603249] [<c014d027>] ? do_acct_process+0x68d/0x6b2 [ 3183.603257] [<c015b46c>] ? find_get_page+0x1d/0x81 [ 3183.603268] [<c018df9f>] ? mntput_no_expire+0x19/0xb3 [ 3183.603276] [<c017c9c7>] ? __fput+0x17c/0x184 [ 3183.603286] [<c014d09f>] ? acct_process+0x53/0x66 [ 3183.603294] [<c012a318>] ? do_exit+0x174/0x573 [ 3183.603303] [<c012a778>] ? do_group_exit+0x61/0x88 [ 3183.603311] [<c012a7b2>] ? sys_exit_group+0x13/0x17 [ 3183.603320] [<c0102994>] ? sysenter_do_call+0x12/0x28 [ 3183.603419] ---[ end trace cba419e95b73d96f ]--- I'm not sure why ext3 journal is involved. I've run the case twice and both turned out with the same trace messages. > > # Before you apply this patch, > # apply following patch which I sent before: > http://marc.info/?l=linux-ext4&m=125186152727422&w=2 > > Regards, > Akira Fujita > > --- > fs/ext4/move_extent.c | 56 ++++++++++++++++++++++++++++++++---------------- > 1 files changed, 37 insertions(+), 19 deletions(-) > > diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c > index 0d10f8b..052acd9 100644 > --- a/fs/ext4/move_extent.c > +++ b/fs/ext4/move_extent.c > @@ -25,6 +25,8 @@ > if (IS_ERR(path)) { \ > ret = PTR_ERR(path); \ > path = NULL; \ > + } else if (path[ext_depth(inode)].p_ext == NULL) { \ > + ret = -ENODATA; \ > } \ > } while (0) > > @@ -284,7 +286,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, > > if (new_flag) { > get_ext_path(orig_path, orig_inode, eblock, err); > - if (orig_path == NULL) > + if (err) > goto out; > > if (ext4_ext_insert_extent(handle, orig_inode, > @@ -295,7 +297,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, > if (end_flag) { > get_ext_path(orig_path, orig_inode, > le32_to_cpu(end_ext->ee_block) - 1, err); > - if (orig_path == NULL) > + if (err) > goto out; > > if (ext4_ext_insert_extent(handle, orig_inode, > @@ -554,8 +556,10 @@ mext_leaf_block(handle_t *handle, struct inode *orig_inode, > * @orig_off: block offset of original inode > * @donor_off: block offset of donor inode > * @max_count: the maximun length of extents > + * > + * Return 0 on success, or a negative error value on failure. > */ > -static void > +static int > mext_calc_swap_extents(struct ext4_extent *tmp_dext, > struct ext4_extent *tmp_oext, > ext4_lblk_t orig_off, ext4_lblk_t donor_off, > @@ -564,6 +568,19 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext, > ext4_lblk_t diff, orig_diff; > struct ext4_extent dext_old, oext_old; > > + BUG_ON(orig_off != donor_off); > + > + /* original and donor extents have to cover the same block offset */ > + if (orig_off < le32_to_cpu(tmp_oext->ee_block) || > + le32_to_cpu(tmp_oext->ee_block) + > + ext4_ext_get_actual_len(tmp_oext) - 1 < orig_off) > + return -ENODATA; > + > + if (orig_off < le32_to_cpu(tmp_dext->ee_block) || > + le32_to_cpu(tmp_dext->ee_block) + > + ext4_ext_get_actual_len(tmp_dext) - 1 < orig_off) > + return -ENODATA; > + > dext_old = *tmp_dext; > oext_old = *tmp_oext; > > @@ -591,6 +608,8 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext, > > copy_extent_status(&oext_old, tmp_dext); > copy_extent_status(&dext_old, tmp_oext); > + > + return 0; > } > > /** > @@ -632,12 +651,12 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, > > /* Get the original extent for the block "orig_off" */ > get_ext_path(orig_path, orig_inode, orig_off, err); > - if (orig_path == NULL) > + if (err) > goto out; > > /* Get the donor extent for the head */ > get_ext_path(donor_path, donor_inode, donor_off, err); > - if (donor_path == NULL) > + if (err) > goto out; > depth = ext_depth(orig_inode); > oext = orig_path[depth].p_ext; > @@ -647,8 +666,10 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, > dext = donor_path[depth].p_ext; > tmp_dext = *dext; > > - mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, > + err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, > donor_off, count); > + if (err) > + goto out; > > /* Loop for the donor extents */ > while (1) { > @@ -679,7 +700,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, > if (orig_path) > ext4_ext_drop_refs(orig_path); > get_ext_path(orig_path, orig_inode, orig_off, err); > - if (orig_path == NULL) > + if (err) > goto out; > depth = ext_depth(orig_inode); > oext = orig_path[depth].p_ext; > @@ -694,7 +715,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, > ext4_ext_drop_refs(donor_path); > get_ext_path(donor_path, donor_inode, > donor_off, err); > - if (donor_path == NULL) > + if (err) > goto out; > depth = ext_depth(donor_inode); > dext = donor_path[depth].p_ext; > @@ -705,9 +726,10 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, > } > tmp_dext = *dext; > > - mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, > - donor_off, > - count - replaced_count); > + err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, > + donor_off, count - replaced_count); > + if (err) > + goto out; > } > > out: > @@ -1147,20 +1169,16 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, > len -= block_end - file_end; > > get_ext_path(orig_path, orig_inode, block_start, ret); > - if (orig_path == NULL) > + if (ret) > goto out2; > > /* Get path structure to check the hole */ > get_ext_path(holecheck_path, orig_inode, block_start, ret); > - if (holecheck_path == NULL) > + if (ret) > goto out; > > depth = ext_depth(orig_inode); > ext_cur = holecheck_path[depth].p_ext; > - if (ext_cur == NULL) { > - ret = -EINVAL; > - goto out; > - } > > /* > * Get proper extent whose ee_block is beyond block_start > @@ -1283,7 +1301,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, > ext4_ext_drop_refs(holecheck_path); > get_ext_path(holecheck_path, orig_inode, > seq_start, ret); > - if (holecheck_path == NULL) > + if (ret) > break; > depth = holecheck_path->p_depth; > > @@ -1291,7 +1309,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, > if (orig_path) > ext4_ext_drop_refs(orig_path); > get_ext_path(orig_path, orig_inode, seq_start, ret); > - if (orig_path == NULL) > + if (ret) > break; > > ext_cur = holecheck_path[depth].p_ext; > -- Best Regards, Peng Tao State Key Laboratory of Networking and Switching Technology Beijing Univ. of Posts and Telecoms. -- 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
