ioctl_xfs_fsop_geometry(2)

1IOCTL-XFS-FSOP-GEOMETRY(2)    System Calls Manual   IOCTL-XFS-FSOP-GEOMETRY(2)
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NAME

6       ioctl_xfs_fsop_geometry - report XFS filesystem layout and features
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SYNOPSIS

9       #include <xfs/xfs_fs.h>
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11       int ioctl(int fd, XFS_IOC_FSOP_GEOMETRY, struct xfs_fsop_geom*arg);
12       int  ioctl(int  fd,  XFS_IOC_FSOP_GEOMETRY_V4,  struct xfs_fsop_geom_v4
13       *arg);
14       int ioctl(int  fd,  XFS_IOC_FSOP_GEOMETRY_V1,  struct  xfs_fsop_geom_v1
15       *arg);
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DESCRIPTION

18       Report  the  details  of  an XFS filesystem layout, features, and other
19       descriptive items.  This information is conveyed in a structure of  the
20       following form:
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22           struct xfs_fsop_geom {
23                __u32         blocksize;
24                __u32         rtextsize;
25                __u32         agblocks;
26                __u32         agcount;
27                __u32         logblocks;
28                __u32         sectsize;
29                __u32         inodesize;
30                __u32         imaxpct;
31                __u64         datablocks;
32                __u64         rtblocks;
33                __u64         rtextents;
34                __u64         logstart;
35                unsigned char uuid[16];
36                __u32         sunit;
37                __u32         swidth;
38                __s32         version;
39                __u32         flags;
40                __u32         logsectsize;
41                __u32         rtsectsize;
42                __u32         dirblocksize;
43                /* struct xfs_fsop_geom_v1 stops here. */
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45                __u32         logsunit;
46                /* struct xfs_fsop_geom_v4 stops here. */
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48                __u32         sick;
49                __u32         checked;
50                __u64         reserved[17];
51           };
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53       blocksize is the size of a fundamental filesystem block, in bytes.
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55       rtextsize is the size of an extent on the realtime volume, in bytes.
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57       agblocks  is  the  size  of an allocation group, in units of filesystem
58       blocks.
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60       agcount is the number of allocation groups in the filesystem.
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62       logblocks is the size of the log, in units of filesystem blocks.
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64       sectsize is the smallest amount of data that can be written to the data
65       device atomically, in bytes.
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67       inodesize is the size of an inode record, in bytes.
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69       imaxpct  is  the maximum percentage of the filesystem that can be allo‐
70       cated to inode record blocks.
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72       datablocks is the size of the  data  device,  in  units  of  filesystem
73       blocks.
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75       rtblocks  is  the  size  of the realtime device, in units of filesystem
76       blocks.
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78       rtextents is the number of extents that can be allocated on  the  real‐
79       time device.
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81       logstart  is  the  start of the log, in units of filesystem blocks.  If
82       the filesystem has an external log, this will be zero.
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84       uuid is the universal unique identifier of the filesystem.
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86       sunit is what the filesystem has been told is the size of a RAID stripe
87       unit on the underlying data device, in filesystem blocks.
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89       swidth  is  what  the  filesystem  has been told is the width of a RAID
90       stripe on the underlying data device, in units of RAID stripe units.
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92       version  is  the  version  of  this  structure.   This  value  will  be
93       XFS_FSOP_GEOM_VERSION.
94
95       flags  tell  us  what features are enabled on the filesystem.  Refer to
96       the section FILESYSTEM FEATURE FLAGS below for more  information  about
97       each feature.
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99       logsectsize  is  the smallest amount of data that can be written to the
100       log device atomically, in bytes.
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102       rtsectsize is the smallest amount of data that can be  written  to  the
103       realtime device atomically, in bytes.
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105       dirblocksize is the size of directory blocks, in bytes.
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107       logsunit  is  what  the  filesystem has been told is the size of a RAID
108       stripe unit on the underlying log device, in filesystem  blocks.   This
109       field is meaningful only if the flag XFS_FSOP_GEOM_FLAGS_LOGV2 is set.
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111       The  fields  sick  and  checked indicate the relative health of various
112       whole-filesystem metadata.  Please see the section XFS METADATA  HEALTH
113       REPORTING for more details.
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115       reserved is set to zero.
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FILESYSTEM FEATURE FLAGS

118       Filesystem features are reported to userspace as a combination the fol‐
119       lowing flags:
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121       XFS_FSOP_GEOM_FLAGS_ATTR
122              Extended attributes are present.
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124       XFS_FSOP_GEOM_FLAGS_NLINK
125              Files on this filesystem support up to 2^32 hard links.  If this
126              flag  is  not  set,  files on this filesystem support only up to
127              2^16 hard links.
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129       XFS_FSOP_GEOM_FLAGS_QUOTA
130              Quotas are enabled.
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132       XFS_FSOP_GEOM_FLAGS_IALIGN
133              Inodes are aligned for better performance.
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135       XFS_FSOP_GEOM_FLAGS_DALIGN
136              Filesystem tries to align data block allocations to RAID  stripe
137              units for better performance.
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139       XFS_FSOP_GEOM_FLAGS_SHARED
140              Unused.
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142       XFS_FSOP_GEOM_FLAGS_EXTFLG
143              Filesystem supports unwritten extents.
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145       XFS_FSOP_GEOM_FLAGS_DIRV2
146              Directories are in version 2 format and maintain free space data
147              for better performance.  Version 1  format  directories  are  no
148              longer supported.
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150       XFS_FSOP_GEOM_FLAGS_LOGV2
151              Log uses the V2 format.
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153       XFS_FSOP_GEOM_FLAGS_SECTOR
154              The log device has a sector size larger than 512 bytes.
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156       XFS_FSOP_GEOM_FLAGS_ATTR2
157              Filesystem contains V2 extended attributes.
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159       XFS_FSOP_GEOM_FLAGS_PROJID32
160              Project  IDs  can be as large as 2^32.  If this flag is not set,
161              the filesystem supports only 2^16 project IDs.
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163       XFS_FSOP_GEOM_FLAGS_DIRV2CI
164              Case-insensitive lookups are supported on directories.
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166       XFS_FSOP_GEOM_FLAGS_LAZYSB
167              On-disk superblock counters are updated only at unmount time.
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169       XFS_FSOP_GEOM_FLAGS_V5SB
170              Metadata blocks are self describing and contain checksums.
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172       XFS_FSOP_GEOM_FLAGS_FTYPE
173              Directories contain inode types in directory entries.
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175       XFS_FSOP_GEOM_FLAGS_FINOBT
176              Filesystem maintains an index of free inodes.
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178       XFS_FSOP_GEOM_FLAGS_SPINODES
179              Filesystem may allocate discontiguous  inode  chunks  when  free
180              space is fragmented.
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182       XFS_FSOP_GEOM_FLAGS_RMAPBT
183              Filesystem stores reverse mappings of blocks to owners.
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185       XFS_FSOP_GEOM_FLAGS_REFLINK
186              Filesystem supports sharing blocks between files.
187

XFS METADATA HEALTH REPORTING

189       The  online filesystem checking utility scans metadata and records what
190       it finds in the kernel incore state.  The following scheme is used  for
191       userspace to read the incore health status of the filesystem:
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194       · If  a given sick flag is set in sick, then that piece of metadata has
195         been observed to be damaged.  The same bit should be set in checked.
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197       · If a given sick flag is set in checked but is not set in  sick,  then
198         that piece of metadata has been checked and is not faulty.
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200       · If a given sick flag is not set in checked, then no conclusion can be
201         made.
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203       The following flags apply to these fields:
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205           XFS_FSOP_GEOM_SICK_COUNTERS
206                  Inode and space summary counters.
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208           XFS_FSOP_GEOM_SICK_UQUOTA
209                  User quota information.
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211           XFS_FSOP_GEOM_SICK_GQUOTA
212                  Group quota information.
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214           XFS_FSOP_GEOM_SICK_PQUOTA
215                  Project quota information.
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217           XFS_FSOP_GEOM_SICK_RT_BITMAP
218                  Free space bitmap for the realtime device.
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220           XFS_FSOP_GEOM_SICK_RT_SUMMARY
221                  Free space summary for the realtime device.
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RETURN VALUE

225       On error, -1 is returned, and errno is set to indicate the error.
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ERRORS

228       Error codes can be one of, but are not limited to, the following:
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230       EFAULT The kernel was not able to copy into the userspace buffer.
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232       EFSBADCRC
233              Metadata checksum validation failed while performing the query.
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235       EFSCORRUPTED
236              Metadata corruption was encountered while performing the query.
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238       EIO    An I/O error was encountered while performing the query.
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CONFORMING TO

241       This API is specific to XFS filesystem on the Linux kernel.
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