From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:45008 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750883AbaI3VZi (ORCPT ); Tue, 30 Sep 2014 17:25:38 -0400 Received: from pps.filterd (m0044012 [127.0.0.1]) by mx0a-00082601.pphosted.com (8.14.5/8.14.5) with SMTP id s8ULLklx028956 for ; Tue, 30 Sep 2014 14:25:37 -0700 Received: from mail.thefacebook.com (mailwest.thefacebook.com [173.252.71.148]) by mx0a-00082601.pphosted.com with ESMTP id 1pqyvt8rvh-1 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=OK) for ; Tue, 30 Sep 2014 14:25:37 -0700 From: Josef Bacik To: Subject: [PATCH] Btrfs-progs: add the ability to fix shifted item offsets Date: Tue, 30 Sep 2014 17:25:34 -0400 Message-ID: <1412112334-14315-1-git-send-email-jbacik@fb.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: A user had a corrupted fs where the items had been shifted improperly. This patch adds the ability to fix this sort of problem within fsck. We will simply shift the item over to the proper offset and update the offsets to make sure they are correct. I tested this with a hand crafted fs that was broken in the same way as the user, and I've included the file as a new test. Thanks, Signed-off-by: Josef Bacik --- cmds-check.c | 113 +++++++++++++++++++++++++++++---- tests/fsck-tests/003-shift-offsets.img | Bin 0 -> 4096 bytes 2 files changed, 100 insertions(+), 13 deletions(-) create mode 100644 tests/fsck-tests/003-shift-offsets.img diff --git a/cmds-check.c b/cmds-check.c index 4c01330..03b0fbd 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -2413,15 +2413,9 @@ static int swap_values(struct btrfs_root *root, struct btrfs_path *path, return 0; } -/* - * Attempt to fix basic block failures. Currently we only handle bad key - * orders, we will cycle through the keys and swap them if necessary. - */ -static int try_to_fix_bad_block(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct extent_buffer *buf, - struct btrfs_disk_key *parent_key, - enum btrfs_tree_block_status status) +static int fix_key_order(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *buf) { struct btrfs_path *path; struct btrfs_key k1, k2; @@ -2429,9 +2423,6 @@ static int try_to_fix_bad_block(struct btrfs_trans_handle *trans, int level; int ret; - if (status != BTRFS_TREE_BLOCK_BAD_KEY_ORDER) - return -EIO; - k1.objectid = btrfs_header_owner(buf); k1.type = BTRFS_ROOT_ITEM_KEY; k1.offset = (u64)-1; @@ -2482,6 +2473,103 @@ static int try_to_fix_bad_block(struct btrfs_trans_handle *trans, return ret; } +static int fix_item_offset(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *buf) +{ + struct btrfs_path *path; + struct btrfs_key k1; + int i; + int level; + int ret; + + k1.objectid = btrfs_header_owner(buf); + k1.type = BTRFS_ROOT_ITEM_KEY; + k1.offset = (u64)-1; + + root = btrfs_read_fs_root(root->fs_info, &k1); + if (IS_ERR(root)) + return -EIO; + + record_root_in_trans(trans, root); + + path = btrfs_alloc_path(); + if (!path) + return -EIO; + + level = btrfs_header_level(buf); + path->lowest_level = level; + path->skip_check_block = 1; + if (level) + btrfs_node_key_to_cpu(buf, &k1, 0); + else + btrfs_item_key_to_cpu(buf, &k1, 0); + + ret = btrfs_search_slot(trans, root, &k1, path, 0, 1); + if (ret) { + btrfs_free_path(path); + return -EIO; + } + + buf = path->nodes[level]; + for (i = 0; i < btrfs_header_nritems(buf); i++) { + unsigned int shift = 0, offset; + + if (i == 0 && btrfs_item_end_nr(buf, i) != + BTRFS_LEAF_DATA_SIZE(root)) { + if (btrfs_item_end_nr(buf, i) > + BTRFS_LEAF_DATA_SIZE(root)) { + fprintf(stderr, "item is off the end of the " + "leaf, can't fix\n"); + ret = -EIO; + break; + } + shift = BTRFS_LEAF_DATA_SIZE(root) - + btrfs_item_end_nr(buf, i); + } else if (i > 0 && btrfs_item_end_nr(buf, i) != + btrfs_item_offset_nr(buf, i - 1)) { + if (btrfs_item_end_nr(buf, i) > + btrfs_item_offset_nr(buf, i - 1)) { + fprintf(stderr, "items overlap, can't fix\n"); + ret = -EIO; + break; + } + shift = btrfs_item_offset_nr(buf, i - 1) - + btrfs_item_end_nr(buf, i); + } + if (!shift) + continue; + + printf("Shifting item nr %d by %u bytes in block %llu\n", + i + 1, shift, (unsigned long long)buf->start); + offset = btrfs_item_offset_nr(buf, i); + memmove_extent_buffer(buf, offset + shift, offset, + btrfs_item_size_nr(buf, i)); + btrfs_set_item_offset(buf, btrfs_item_nr(i), + offset + shift); + btrfs_mark_buffer_dirty(buf); + } + + btrfs_free_path(path); + return ret; +} + +/* + * Attempt to fix basic block failures. If we can't fix it for whatever reason + * then just return -EIO. + */ +static int try_to_fix_bad_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *buf, + enum btrfs_tree_block_status status) +{ + if (status == BTRFS_TREE_BLOCK_BAD_KEY_ORDER) + return fix_key_order(trans, root, buf); + if (status == BTRFS_TREE_BLOCK_INVALID_OFFSETS) + return fix_item_offset(trans, root, buf); + return -EIO; +} + static int check_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct cache_tree *extent_cache, @@ -2520,7 +2608,6 @@ static int check_block(struct btrfs_trans_handle *trans, if (status != BTRFS_TREE_BLOCK_CLEAN) { if (repair) status = try_to_fix_bad_block(trans, root, buf, - &rec->parent_key, status); if (status != BTRFS_TREE_BLOCK_CLEAN) { ret = -EIO; diff --git a/tests/fsck-tests/003-shift-offsets.img b/tests/fsck-tests/003-shift-offsets.img new file mode 100644 index 0000000000000000000000000000000000000000..ba762cedf2b2e17b05596e8fe5cd38f83e819247 GIT binary patch literal 4096 zcmeH}cTiK=9>)V30V#_>2)GnM>AflfhF~bt5rm~GJ%CiDW(f#H5SAjnBcTX}62;IV zz=CuXF=zq-K?M<{NeI;}@OEb3?!5Qr{rP6zp1JeApL@>lo^yZSx%YQ&qI+iGoQQop z;P=LGc&0l(4uSEI006CH6+PC@W0gL2)ZKN=lgA<5$2@b)J;xk=#DLCYbvW)h#=qrn z2mW^8f5(AP5+aXpq(6#bS)H7rxKx?=Ss0Q0Ll+Eq4AfZu8AsxjQTx!6L=q{izlCqbET91rhE&h z#e{mv*bv3kOCOKC%gnyPfE`r&CE8s6v~HI;53m%#&v%KjR>fw_%LevslRa;r&N7VQ z?oLeQ2He<1H;}yOpL3?!Gii48MBJ;7V{b}Z>*6=a^S$?f&y8c#lNuk=GrqVXq=F)3p_PK~-Z2wYxS~qR-)FuCuyzLNbcKIi;KRYZ|N(Lz<&yu^?ONR8@Rgj~!$*vvqZNPcZEjjWy* z>(5aummQlb9t6)tr1h%5pe@jVrdAQ+hb|R*-{!i(bKfJ_W0hdZ8CyopALGfl39s{U z=;?uLp{p8qOSM{62&5N|!aV3t93MnDoNu>X$m6)Cm2_PQE(OYVc4_N5N9g?Fl{h<7 znWvE%QkgC!e7>OYph3yPQ;d203M9vGq43)%weXI6NbdadbN(D8?AiNHYQF6ZFTU0F zmRI1=N?HmnwJfLlYj&=52(1lHWRRO8Z0iIKeSC;RfcGfD0ugrSc~jq;qTJB zVyaGk)zOA)?0;Hwmbt_S-uR_^CrOZu0Ty3}ekt;O9sRZ{mCU{TI$A)ofEP}Z=QI=Y zLobKPh^H{`=*~_V&(_#t#mjpaRaU*aAQYHC4d;{1%~#$Hw7!k!X0dQWJIy`kZZnQ0 z$hLD9mqy!x1s+GEnS(6fmu6fA*2&sepN}>LBTMN8w|PMHE!e`-P=|LgRI2QAGoh>C zthZ0sQy1I9X>6)>u9xek6PSf!u&z4^HDb8;9Zmj`KQE!J1Sb@wz__#0?pCs1lv@h* zffg7|o#8>_nqY1Psf)Pq>UbN8H(q6_hx#R5+r8WjLqH7=UafHk9_bcHUg`&2I6BHE ztcq}PXL!)CM)zB8X0~n6ypoh4ZdW12W~Y)+qT&9j)G8uuc+j*4IpAi6^rAS()^Au~ zSeu6>wQ7k!s67YLFw& zt7suFoJ^w4pI+GQ$WGc+x}2NA_aeCA%@D-u?&~7B9>Qa$rDHU!cC=w@6z+ZJrq5fF zSgB0=2pQ+|m49r0nj~;zE;2LVniIj0Wh9k#JvnKj1yuZLdZN-tiJ^!szjyS800(iR z46_!Li|KZMdI!az(?D31-2aU6dM6!RyB5{oAnAb0-t}cUj0LTLiB=VuwdH;Z!r`EQ zaesrb1FDV$sm(hY1QD|yW7a&RLY^E=gn%`;ElO(me>Xmk)p2cAc0fT$I7gMlbrsg% z>-apgFKup1?w=*$cEBF>N%MhvT{l^H(!b^OOhm&qmBd1+DUoN!lNT>q+ZB3o|CnNG zv!A8^Mr6QA1ztOpX3vSuz#L=+X1=^$yJj&v$4mia)b%R)PTWWUw$H6%;&gEk7vE)&RUrRZHk zU2Z;gO;U*w-3yDkq!*Y79TR?GC%-5%Ev#*;(POvCS(3{9FlM0JQqvC_Yc30Wk%r1f ztpz<>lL!A-JDg{n9Pa|e{DY!qV832os6J;0Ee^)nTQMN*!IUa`+DAKk#PBLuR$*JV z<>vyw#tV7a&5($066Zts2>`%Igcx_#OB z>GR{f@{@*YYCp6TFJ!9OZ$2hmFtnk~KpH7DjqD|N{$2}8+GcY>zX@aGTZMZecTUmB zvCB>VF-~U_xW{ZKx((Hx+H@nu)o^F4oJ{-X>wZl6C4!R2-F60Sz``#(8h}nHJgi*|DQ<`@#|z-&v0j>D421z@oT=fdedd+kzv0#6w_L zPKmWH$#?6K|AL%F#HhpKs+fe}iQN;e3p)x?bp@kof$gx@fjbVK`^*rfwDhAL6>p$z z&I4GxQ*&R-KmPE`K7H4xrE;6`3Y2oPhBaaHw5*AWs(wt289U?UW*rNcz231dp)(*~ z*jx6#8Nc1{1>Xv1hi}f_xeHcoGbUXm2eiM-6{WuHowlxIDRtAd#g$H`jDNAHp9pPk zGnua2^@v+S)URgR>laTO74`{flu7Ow%O_!N1)3-G^@Yq?*`KYMN|xPF$#2btFf7JTM+sWvOtV zA4^{y1!V7GQ|8b_iC0+k!_a6BsYl$nWZs!r1!0)w^y7fJsXfs6jF+Es26!G5?1PmS z-Rrv=l2@<{y9wW-k#G}VCVxUsDG$~gQLt4x>sS(V)lC0^ix^HMsX+hBRzfxTL3g=6 zf|<-@9_gg!R7~-^MBD^trK_8&(g%xcO0cM3u>4cS{Ud|ObDvL9w{7{o6E6cI+mvWX zN9!sPd~V~%U#XA+>WbzlevkZ;E&L|>FukD?)^0O^&KT{6*f|!h7QmB)=dovU06CAC zQ`s-m-)EI%M6=yPKS`FS>u>^USBkRuC%4Jf<&BEY#(6hR@=fZ5hf??*luD!}`j% zJ7twk;-6Wx=)W@yrN1zpZsKvEK7*Y$p#~uKz4?FDd$5}2l~`g#$-K(EF{Rqk^;)&) j>8aW9%KD*Z@@IURbqLpA*ZaS^Mvk$0o+vT;mpT6iVbMSq literal 0 HcmV?d00001 -- 1.8.3.1