1IOCTL-XFS-FSGEOMETRY(2) System Calls Manual IOCTL-XFS-FSGEOMETRY(2)
2
6 ioctl_xfs_fsgeometry - report XFS filesystem layout and features
7
9 #include <xfs/xfs_fs.h>
10 int ioctl(int fd, XFS_IOC_FSGEOMETRY, struct xfs_fsop_geom *arg);
12 int ioctl(int fd, XFS_IOC_FSGEOMETRY_V4, struct xfs_fsop_geom_v4 *arg);
13 int ioctl(int fd, XFS_IOC_FSGEOMETRY_V1, struct xfs_fsop_geom_v1 *arg);
14
16 Report the details of an XFS filesystem layout, features, and other de‐
17 scriptive items. This information is conveyed in a structure of the
18 following form:
19 struct xfs_fsop_geom {
21 __u32 blocksize;
22 __u32 rtextsize;
23 __u32 agblocks;
24 __u32 agcount;
25 __u32 logblocks;
26 __u32 sectsize;
27 __u32 inodesize;
28 __u32 imaxpct;
29 __u64 datablocks;
30 __u64 rtblocks;
31 __u64 rtextents;
32 __u64 logstart;
33 unsigned char uuid[16];
34 __u32 sunit;
35 __u32 swidth;
36 __s32 version;
37 __u32 flags;
38 __u32 logsectsize;
39 __u32 rtsectsize;
40 __u32 dirblocksize;
41 /* struct xfs_fsop_geom_v1 stops here. */
42 __u32 logsunit;
44 /* struct xfs_fsop_geom_v4 stops here. */
45 __u32 sick;
47 __u32 checked;
48 __u64 reserved[17];
49 };
50 blocksize is the size of a fundamental filesystem block, in bytes.
52 rtextsize is the size of an extent on the realtime volume, in bytes.
54 agblocks is the size of an allocation group, in units of filesystem
56 blocks.
57 agcount is the number of allocation groups in the filesystem.
59 logblocks is the size of the log, in units of filesystem blocks.
61 sectsize is the smallest amount of data that can be written to the data
63 device atomically, in bytes.
64 inodesize is the size of an inode record, in bytes.
66 imaxpct is the maximum percentage of the filesystem that can be allo‐
68 cated to inode record blocks.
69 datablocks is the size of the data device, in units of filesystem
71 blocks.
72 rtblocks is the size of the realtime device, in units of filesystem
74 blocks.
75 rtextents is the number of extents that can be allocated on the real‐
77 time device.
78 logstart is the start of the log, in units of filesystem blocks. If
80 the filesystem has an external log, this will be zero.
81 uuid is the universal unique identifier of the filesystem.
83 sunit is what the filesystem has been told is the size of a RAID stripe
85 unit on the underlying data device, in filesystem blocks.
86 swidth is what the filesystem has been told is the width of a RAID
88 stripe on the underlying data device, in units of RAID stripe units.
89 version is the version of this structure. This value will be
91 XFS_FSOP_GEOM_VERSION.
92 flags tell us what features are enabled on the filesystem. Refer to
94 the section FILESYSTEM FEATURE FLAGS below for more information about
95 each feature.
96 logsectsize is the smallest amount of data that can be written to the
98 log device atomically, in bytes.
99 rtsectsize is the smallest amount of data that can be written to the
101 realtime device atomically, in bytes.
102 dirblocksize is the size of directory blocks, in bytes.
104 logsunit is what the filesystem has been told is the size of a RAID
106 stripe unit on the underlying log device, in filesystem blocks. This
107 field is meaningful only if the flag XFS_FSOP_GEOM_FLAGS_LOGV2 is set.
108 The fields sick and checked indicate the relative health of various
110 whole-filesystem metadata. Please see the section XFS METADATA HEALTH
111 REPORTING for more details.
112 reserved is set to zero.
114
116 Filesystem features are reported to userspace as a combination the fol‐
117 lowing flags:
118 XFS_FSOP_GEOM_FLAGS_ATTR
120 Extended attributes are present.
121 XFS_FSOP_GEOM_FLAGS_NLINK
123 Files on this filesystem support up to 2^32 hard links. If this
124 flag is not set, files on this filesystem support only up to
125 2^16 hard links.
126 XFS_FSOP_GEOM_FLAGS_QUOTA
128 Quotas are enabled.
129 XFS_FSOP_GEOM_FLAGS_IALIGN
131 Inodes are aligned for better performance.
132 XFS_FSOP_GEOM_FLAGS_DALIGN
134 Filesystem tries to align data block allocations to RAID stripe
135 units for better performance.
136 XFS_FSOP_GEOM_FLAGS_SHARED
138 Unused.
139 XFS_FSOP_GEOM_FLAGS_EXTFLG
141 Filesystem supports unwritten extents.
142 XFS_FSOP_GEOM_FLAGS_DIRV2
144 Directories are in version 2 format and maintain free space data
145 for better performance. Version 1 format directories are no
146 longer supported.
147 XFS_FSOP_GEOM_FLAGS_LOGV2
149 Log uses the V2 format.
150 XFS_FSOP_GEOM_FLAGS_SECTOR
152 The log device has a sector size larger than 512 bytes.
153 XFS_FSOP_GEOM_FLAGS_ATTR2
155 Filesystem contains V2 extended attributes.
156 XFS_FSOP_GEOM_FLAGS_PROJID32
158 Project IDs can be as large as 2^32. If this flag is not set,
159 the filesystem supports only 2^16 project IDs.
160 XFS_FSOP_GEOM_FLAGS_DIRV2CI
162 Case-insensitive lookups are supported on directories.
163 XFS_FSOP_GEOM_FLAGS_LAZYSB
165 On-disk superblock counters are updated only at unmount time.
166 XFS_FSOP_GEOM_FLAGS_V5SB
168 Metadata blocks are self describing and contain checksums.
169 XFS_FSOP_GEOM_FLAGS_FTYPE
171 Directories contain inode types in directory entries.
172 XFS_FSOP_GEOM_FLAGS_FINOBT
174 Filesystem maintains an index of free inodes.
175 XFS_FSOP_GEOM_FLAGS_SPINODES
177 Filesystem may allocate discontiguous inode chunks when free
178 space is fragmented.
179 XFS_FSOP_GEOM_FLAGS_RMAPBT
181 Filesystem stores reverse mappings of blocks to owners.
182 XFS_FSOP_GEOM_FLAGS_REFLINK
184 Filesystem supports sharing blocks between files.
185
187 The online filesystem checking utility scans metadata and records what
188 it finds in the kernel incore state. The following scheme is used for
189 userspace to read the incore health status of the filesystem:
190 • If a given sick flag is set in sick, then that piece of metadata has
193 been observed to be damaged. The same bit should be set in checked.
194 • If a given sick flag is set in checked but is not set in sick, then
196 that piece of metadata has been checked and is not faulty.
197 • If a given sick flag is not set in checked, then no conclusion can be
199 made.
200 The following flags apply to these fields:
202 XFS_FSOP_GEOM_SICK_COUNTERS
204 Inode and space summary counters.
205 XFS_FSOP_GEOM_SICK_UQUOTA
207 User quota information.
208 XFS_FSOP_GEOM_SICK_GQUOTA
210 Group quota information.
211 XFS_FSOP_GEOM_SICK_PQUOTA
213 Project quota information.
214 XFS_FSOP_GEOM_SICK_RT_BITMAP
216 Free space bitmap for the realtime device.
217 XFS_FSOP_GEOM_SICK_RT_SUMMARY
219 Free space summary for the realtime device.
220
223 On error, -1 is returned, and errno is set to indicate the error.
224
226 Error codes can be one of, but are not limited to, the following:
227 EFAULT The kernel was not able to copy into the userspace buffer.
229 EFSBADCRC
231 Metadata checksum validation failed while performing the query.
232 EFSCORRUPTED
234 Metadata corruption was encountered while performing the query.
235 EIO An I/O error was encountered while performing the query.
237
239 This API is specific to XFS filesystem on the Linux kernel.
240
242 ioctl(2)
243XFS 2019-06-17 IOCTL-XFS-FSGEOMETRY(2)