Convert images that are purely screenshots of xfs_db sessions to text, to reduce the document size and format better. Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> --- .../XFS_Filesystem_Structure/data_extents.asciidoc | 37 ++++- .../XFS_Filesystem_Structure/directories.asciidoc | 65 +++++++- .../extended_attributes.asciidoc | 161 ++++++++++++++++++-- .../symbolic_links.asciidoc | 15 ++ 4 files changed, 251 insertions(+), 27 deletions(-) diff --git a/design/XFS_Filesystem_Structure/data_extents.asciidoc b/design/XFS_Filesystem_Structure/data_extents.asciidoc index d7f51e4..b71bc52 100644 --- a/design/XFS_Filesystem_Structure/data_extents.asciidoc +++ b/design/XFS_Filesystem_Structure/data_extents.asciidoc @@ -132,14 +132,43 @@ u.bmx[0-2] = [startoff,startblock,blockcount,extentflag] Raw disk version of the inode with the third extent highlighted (+di_u+ always starts at offset 0x64): -.Raw inode contents with extents -image::images/code/33a.png[] +[subs="quotes"] +---- +xfs_db> type text +xfs_db> p +00: 49 4e 81 a4 01 02 00 01 00 00 00 00 00 00 00 00 IN.............. +10: 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 01 ................ +20: 44 b6 88 dd 2f 8a ed d0 44 b6 88 f7 10 8c 5b de D.......D....... +30: 44 b6 88 f7 10 8c 5b d0 00 00 00 00 01 7b b0 00 D............... +40: 00 00 00 00 00 00 17 bb 00 00 00 00 00 00 00 03 ................ +50: 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00 ................ +60: ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 0d ................ +70: 5e a0 07 e9 00 00 00 00 00 0f d2 00 00 00 00 0f ................ +80: 58 e0 07 e9 *00 00 00 00 00 1f a4 00 00 00 00 11 X............... +90: 53 20 07 e9* 00 00 00 00 00 00 00 00 00 00 00 00 S............... +a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +be: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +co: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +do: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +fo: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +---- We can expand the highlighted section into the following bit array from MSB to LSB with the file offset and the block count highlighted: -.Encoded extent -image::images/code/33b.png[] +[subs="quotes"] +---- +127-96: 0**000 0000 0000 0000 0000 0000 0000 0000** + 95-64: **0000 0000 0001 1111 1010 010**0 0000 0000 + 63-32: 0000 0000 0000 0000 0000 0000 0000 1111 + 31-0 : 0101 1000 111**0 0000 0000 0111 1110 1001** + +Grouping by highlights we get: + file offset = 0x0fd2 (4050) + start block = 0x7ac7 (31431) + block count = 0x07e9 (2025) +---- A 4MB file with two extents and a hole in the middle, the first extent containing 64KB of data, the second about 4MB in containing 32KB (+write+ 64KB, diff --git a/design/XFS_Filesystem_Structure/directories.asciidoc b/design/XFS_Filesystem_Structure/directories.asciidoc index 76d5df7..beabe20 100644 --- a/design/XFS_Filesystem_Structure/directories.asciidoc +++ b/design/XFS_Filesystem_Structure/directories.asciidoc @@ -149,8 +149,24 @@ u.sfdir2.list[3].inumber.i4 = 25165956 The raw data on disk with the first entry highlighted. The six byte header precedes the first entry: -.Shortform Directory entry detail -image::images/code/40.png[] +[subs="quotes"] +---- +xfs_db> type text +xfs_db> p +00: 49 4e 41 ed 01 01 00 02 00 00 00 00 00 00 00 00 INA............. +10: 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 02 ................ +20: 44 ad 3a 83 1d a9 4a d0 44 ad 3a ab 0b c7 a7 d0 D.....J.D....... +30: 44 ad 3a ab 0b c7 a7 d0 00 00 00 00 00 00 00 5e D............... +40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +50: 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00 ................ +60: ff ff ff ff 04 00 00 00 00 80 *0f 00 30 66 72 61* ............0fra +70: *6d 65 30 30 30 30 30 30 2e 74 73 74 01 80 00 81* me000000.tst.... +80: 0f 00 50 66 72 61 6d 65 30 30 30 30 30 31 2e 74 ..Pframe000001.t +90: 73 74 01 80 00 82 0f 00 70 66 72 61 6d 65 30 30 st......pframe00 +a0: 30 30 30 32 2e 74 73 74 01 80 00 83 0f 00 90 66 0002.tst........ +b0: 72 61 6d 65 30 30 30 30 30 33 2e 74 73 74 01 80 rame000003.tst.. +cO: 00 84 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +---- Next, an entry is deleted (frame000001.tst), and any entries after the deleted entry are moved or compacted to "cover" the hole: @@ -479,8 +495,21 @@ and the length of the space. The tag remains intact at the +offset+length - sizeof(tag)+. The address for the hash is also cleared. The affected areas are highlighted below: -.Block directory free entry detail -image::images/code/46.png[] +[subs="quotes"] +---- +090: 00 00 00 00 02 00 00 84 0f 66 72 61 6d 65 30 30 ..........frame00 +0a0: 30 30 30 33 2e 74 73 74 00 00 00 00 00 00 00 90 0003.tst......... +0b0: *ff ff 00 20* 02 00 00 85 0f 66 72 61 6d 65 30 30 ..........frame00 +0c0: 30 30 30 34 2e 74 73 74 00 00 00 00 *00 00 00 b0* 0004.tst......... +0d0: 00 00 00 00 02 00 00 86 0f 66 72 61 6d 65 30 30 ..........frame00 +0e0: 30 30 30 35 2e 74 73 74 00 00 00 00 00 00 00 0d 0005.tst......... +... +fb0: 00 00 17 2e 00 00 00 04 83 a0 40 b4 00 00 00 0e ................. +fc0: 93 a0 40 b4 00 00 00 12 a3 a0 40 b4 00 00 00 06 ................. +fd0: b3 a0 40 b4 00 00 00 0a c3 a0 40 b4 00 00 00 1e ................. +fe0: d3 a0 40 b4 00 00 00 22 e3 a0 40 b4 *00 00 00 00* ................. +ff0: f3 a0 40 b4 00 00 00 1a 00 00 00 0a *00 00 00 01* ................. +---- @@ -1049,8 +1078,13 @@ block's +bestfree[0].length+ value. The raw disk layout, old data is not cleared after the array. The fbests array is highlighted: -.Node directory freespace detail -image::images/code/57.png[] +[subs="quotes"] +---- +xfs_db> type text +xfs_db> p +000: 58 44 32 46 00 00 00 00 00 00 00 05 00 00 00 05 XD2F............ +010: *00 10 00 10 00 10 00 10 3f 50* 00 00 1f 01 ff ff .........P...... +---- TODO: Example with a hole in the middle @@ -1188,6 +1222,21 @@ The leaves at each the end of a node always point to the end leaves in adjacent nodes. Directory block 8388928 forward pointer is to block 8388919, and vice versa as highlighted in the following example: -.B+tree directory pointer detail -image::images/code/60.png[] +[subs="quotes"] +---- +xfs_db> dblock 8388928 +xfs_db> type dir2 +xfs_db> p +lhdr.info.forw = *8388919* +lhdr.info.back = 8388937 +lhdr.info.magic = 0xd2ff +... +xfs_db> dblock 8388919 +xfs_db> type dir2 +xfs_db> p +lhdr.info.forw = 8388706 +lhdr.info.back = *8388928* +lhdr.info.magic = 0xd2ff +... +---- diff --git a/design/XFS_Filesystem_Structure/extended_attributes.asciidoc b/design/XFS_Filesystem_Structure/extended_attributes.asciidoc index 8b32bdf..51f7ff7 100644 --- a/design/XFS_Filesystem_Structure/extended_attributes.asciidoc +++ b/design/XFS_Filesystem_Structure/extended_attributes.asciidoc @@ -128,8 +128,27 @@ a.sfattr.list[1].value = "val1" We can determine the actual inode offset to be 220 (15 x 8 + 100) or +0xdc+. Examining the raw dump, the second attribute is highlighted: -.Shortform Attribute detail -image::images/code/65.png[] +[subs="quotes"] +---- +xfs_db> type text +xfs_db> p +09: 49 4e 81 a4 01 02 00 01 00 00 00 00 00 00 00 00 IN.............. +10: 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 02 ................ +20: 44 be 19 be 38 d1 26 98 44 be 1a be 38 d1 26 98 D...8...D...8... +30: 44 be 1a e1 3a 9a ea 18 00 00 00 00 00 00 00 04 D............... +40: 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 01 ................ +50: 00 00 0f 01 00 00 00 00 00 00 00 00 00 00 00 00 ................ +60: ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 12 ................ +70: 53 a0 00 01 00 00 00 00 00 00 00 00 00 00 00 00 ................ +80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +d0: 00 00 00 00 00 00 00 00 00 00 00 00 *00 18* 02 00 ................ <-- hdr.totsize = 0x18 +e0: 05 00 00 65 6d 70 74 79 *05 04 02 74 72 75 73 74* ...empty...trust +f0: *76 61 6c 31* 00 00 00 00 00 00 00 00 00 00 00 00 val1............ +---- Adding another attribute with attr1, the format is converted to extents and +di_forkoff+ remains unchanged (and all those zeros in the dump above remain @@ -192,8 +211,34 @@ a.sfattr.list[1].value = "val1" Another attribute is added: -.Shortform Multiple Attribute detail -image::images/code/66.png[] +[subs="quotes"] +---- +xfs_db> p +... +core.naextents = 0 +*core.forkoff = 13* +core.aformat = 1 (local) +... +a.sfattr.hdr.totsize = 52 +a.sfattr.hdr.count = 3 +a.sfattr.list[0].namelen = 10 +a.sfattr.list[0].valuelen = 0 +a.sfattr.list[0].root = 0 +a.sfattr.list[0].secure = 0 +a.sfattr.list[0].name = "empty_attr" +a.sfattr.list[1].namelen = 7 +a.sfattr.list[1].valuelen = 4 +a.sfattr.list[1].root = 1 +a.sfattr.list[1].secure = 0 +a.sfattr.list[1].name = "trust_a" +a.sfattr.list[1].value = "val1" +a.sfattr.list[2].namelen = 6 +a.sfattr.list[2].valuelen = 12 +a.sfattr.list[2].root = 0 +a.sfattr.list[2].secure = 0 +a.sfattr.list[2].name = "second" +a.sfattr.list[2].value = "second_value" +---- One more is added: @@ -233,8 +278,27 @@ a.sfattr.list[3].value = "contents" A raw dump is shown to compare with the attr1 dump on a prior page, the header is highlighted: -.Shortform attribute header detail -image::images/code/67.png[] +[subs="quotes"] +---- +xfs_db> type text +xfs_db> p +00: 49 4e 81 a4 01 02 00 01 00 00 00 00 00 00 00 00 IN.............. +10: 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 05 ................ +20: 44 be 24 cd 0f b0 96 18 44 be 24 cd 0f b0 96 18 D.......D....... +30: 44 be 2d f5 01 62 7a 18 00 00 00 00 00 00 00 04 D....bz......... +40: 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 01 ................ +50: 00 00 0a 01 00 00 00 00 00 00 00 00 00 00 00 00 ................ +60: ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 01 ................ +70: 41 c0 00 01 00 00 00 00 00 00 00 00 00 00 00 00 A............... +80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +b0: 00 00 00 00 *00 45 04 00* 0a 00 00 65 6d 70 74 79 .....E.....empty +c0: 5f 61 74 74 72 07 04 02 74 72 75 73 74 5f 61 76 .attr...trust.av +d0: 61 6c 31 06 0c 00 73 65 63 6f 6e 64 73 65 63 6f all...secondseco +e0: 6e 64 5f 76 61 6c 75 65 06 08 04 70 6f 6c 69 63 nd.value...polic +f0: 79 63 6f 6e 74 65 6e 74 73 64 5f 76 61 6c 75 65 ycontentsd.value +---- It can be clearly seen that attr2 allows many more attributes to be stored in an inode before they are moved to another filesystem block. @@ -444,9 +508,19 @@ flag set and the values are printed. A raw disk dump shows the attributes. The last attribute added is highlighted (offset 4044 or 0xfcc): -.Leaf Attribute detail -image::images/code/71.png[] - +[subs="quotes"] +---- +000: 00 00 00 00 00 00 00 00 fb ee 00 00 00 03 00 34 ...............4 +010: 0f cc 00 00 00 38 0f 94 00 00 00 00 00 00 00 00 .....8.......... +020: 1e 9d 39 34 0f cc 01 00 1e 9d 39 37 0f dc 01 00 ..94......97.... +030: fc f8 9d 4f 0f ec 00 00 00 00 00 00 00 00 00 00 ...0............ +040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00................. +... +fc0: 00 00 00 00 00 00 00 00 00 00 00 00 *00 06 05 61* ...............a +fd0: *74 74 72 32 76 61 6c 75 65 32* 00 00 00 06 05 61 ttr2value2.....a +fe0: 74 74 72 31 76 61 6c 75 65 31 00 00 00 00 00 01 ttr1value1...... +ff0: 00 00 77 e4 08 62 69 67 5f 61 74 74 72 00 00 00 ..w..big.attr... +---- [[Node_Attributes]] == Node Attributes @@ -522,16 +596,77 @@ xfs_db> hash attribute_267 In the root btree node, this falls between +0x3437922e+ and +0x3437d22a+, therefore leaf 11 or attribute block 5 will contain the entry. -.Node Attribute lookup detail -image::images/code/73-74.png[] +[subs="quotes"] +---- +xfs_db> ablock 5 +xfs_db> p +hdr.info.forw = 4 +hdr.info.back = 3 +hdr.info.magic = 0xfbee +hdr.count = 96 +hdr.usedbytes = 2688 +hdr.firstused = 1408 +hdr.holes = 0 +hdr.freemap[0-2] = [base,size] 0:[800,608] 1:[0,0] 2:[0,0] +entries[0.95] = [hashval,nameidx,incomplete,root,secure,local] + 0:[0x3437922f,4068,0,0,0,1] + 1:[0x343792a6,4040,0,0,0,1] + 2:[0x343792a7,4012,0,0,0,1] + 3:[0x343792a8,3984,0,0,0,1] + ... + 82:[0x3437d1a7,2892,0,0,0,1] + *83:[0x3437d1a8,2864,0,0,0,1]* + 84:[0x3437d1a9,2836,0,0,0,1] + ... + 95:[0x3437d22a,2528,0,0,0,1] +nvlist[0].valuelen = 10 +nvlist[0].namelen = 13 +nvlist[0].name = "attribute_310" +nvlist[0].value = "value_316\d" +nvlist[1].valuelen = 16 +nvlist[1].namelen = 13 +nvlist[1].name = "attribute_309" +nvlist[1].value = "value_309\d" +nvlist[2].valuelen = 10 +nvlist[2].namelen = 13 +nvlist[2].name = "attribute_308" +nvlist[2].value = "value_308\d" +nvlist[3].valuelen = 10 +nvlist[3].namelen = 13 +nvlist[3].name = "attribute_307" +nvlist[3].value = "value_307\d" +... +nvlist[82].valuelen = 10 +nvlist[82].namelen = 13 +nvlist[82].name = "attribute_268" +nvlist[82].value = "value_268\d" +nvlist[83].valuelen = 10 +nvlist[83].namelen = 13 +nvlist[83].name = "attribute_267" +nvlist[83].value = "value_267\d" +nvlist[84].valuelen = 10 +nvlist[84].namelen = 13 +nvlist[84].name = "attribute_266" +nvlist[84].value = "value_266\d" +... +---- Each of the hash entries has +XFS_ATTR_LOCAL+ flag set (1), which means the attribute's value follows immediately after the name. Raw disk of the name/value pair at offset 2864 (0xb30), highlighted with "value_267\d" following immediately after the name: -.Node Attribute value detail -image::images/code/74.png[] +[subs="quotes"] +---- +b00: 62 75 74 65 5f 32 36 35 76 61 6c 75 65 5f 32 36 bute.265value.26 +b10: 35 0a 00 00 00 0a 0d 61 74 74 72 69 62 75 74 65 5......attribute +b20: 51 32 36 36 76 61 6c 75 65 5f 32 36 36 0a 00 00 .266value.266... +b30: *00 0a 0d 61 74 74 72 69 62 75 74 65 5f 32 36 37* ...attribute.267 +b40: *76 61 6c 75 65 5f 32 36 37 0a* 00 00 00 0a 0d 61 value.267......a +b50: 74 74 72 69 62 75 74 65 5f 32 36 38 76 61 6c 75 ttribute.268va1u +b60: 65 5f 32 36 38 0a 00 00 00 0a 0d 61 74 74 72 69 e.268......attri +b70: 62 75 74 65 5f 32 36 39 76 61 6c 75 65 5f 32 36 bute.269value.26 +---- Each entry starts on a 32-bit (4 byte) boundary, therefore the highlighted entry has 2 unused bytes after it. diff --git a/design/XFS_Filesystem_Structure/symbolic_links.asciidoc b/design/XFS_Filesystem_Structure/symbolic_links.asciidoc index 9c9ca30..af88a1c 100644 --- a/design/XFS_Filesystem_Structure/symbolic_links.asciidoc +++ b/design/XFS_Filesystem_Structure/symbolic_links.asciidoc @@ -38,8 +38,19 @@ u.symlink = "small_target" Raw on-disk data with the link contents highlighted: -.Shortform symbolic link format -image::images/code/61.png[] +[subs="quotes"] +---- +xfs_db> type text +xfs_db> p +00: 49 4e a1 ff 01 01 00 01 00 00 00 00 00 00 00 00 IN.............. +10: 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 01 ................ +20: 44 be e1 c7 03 c4 d4 18 44 be el c7 03 c4 d4 18 D.......D....... +30: 44 be e1 c7 03 c4 d4 18 00 00 00 00 00 00 00 Oc D............... +40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +50: 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00 ................ +60: ff ff ff ff *73 6d 61 6c 6c 5f 74 61 72 67 65 74* ....small.target +70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ +---- [[Extent_Symbolic_Links]] _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
