#include <libxfs.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
+#include <sys/vfs.h>
int aflag = 0; /* Attribute fork. */
int lflag = 0; /* list number of blocks with each extent */
int nflag = 0; /* number of extents specified */
int vflag = 0; /* Verbose output */
int bmv_iflags = 0; /* Input flags for XFS_IOC_GETBMAPX */
+char *progname;
int dofile(char *);
__off64_t file_size(int fd, char * fname);
int i = 0;
int option;
- fname = basename(argv[0]);
+ progname = basename(argv[0]);
while ((option = getopt(argc, argv, "adln:pvV")) != EOF) {
switch (option) {
case 'a':
vflag++;
break;
case 'V':
- printf("%s version %s\n", fname, VERSION);
+ printf("%s version %s\n", progname, VERSION);
break;
default:
fprintf(stderr, "Usage: %s [-adlpV] [-n nx] file...\n",
- fname);
+ progname);
exit(1);
}
}
errno_save = errno; /* in case fstat64 fails */
i = fstat64(fd, &st);
if (i < 0) {
- fprintf(stderr,"fstat64 failed for %s", fname);
- perror("fstat64");
+ fprintf(stderr, "%s: fstat64 failed for %s: %s\n",
+ progname, fname, strerror(errno));
errno = errno_save;
return -1;
}
int
dofile(char *fname)
{
+ int i;
int fd;
+ struct statfs buf;
struct fsxattr fsx;
- int i;
struct getbmapx *map;
- char mbuf[1024];
int map_size;
int loop = 0;
xfs_fsop_geom_t fsgeo;
fd = open(fname, O_RDONLY);
if (fd < 0) {
- sprintf(mbuf, "open %s", fname);
- perror(mbuf);
+ fprintf(stderr, "%s: cannot open \"%s\": %s\n",
+ progname, fname, strerror(errno));
return 1;
}
+ fstatfs(fd, &buf);
+ if (buf.f_type != XFS_SUPER_MAGIC) {
+ fprintf(stderr, "%s: "
+ "specified file [\"%s\"] is not on an XFS filesystem\n",
+ progname, fname);
+ close(fd);
+ return 1;
+ }
if (vflag) {
if (ioctl(fd, XFS_IOC_FSGEOMETRY, &fsgeo) < 0) {
- sprintf(mbuf, "Can't get XFS geom, %s", fname);
- perror(mbuf);
+ fprintf(stderr, "%s: can't get geometry [\"%s\"]: %s\n",
+ progname, fname, strerror(errno));
close(fd);
return 1;
}
fsgeo.agcount);
if ((ioctl(fd, XFS_IOC_FSGETXATTR, &fsx)) < 0) {
- sprintf(mbuf, "Can't read attrs %s", fname);
- perror(mbuf);
+ fprintf(stderr, "%s: cannot read attrs on \"%s\": %s\n",
+ progname, fname, strerror(errno));
close(fd);
return 1;
}
map_size = nflag ? nflag+1 : 32; /* initial guess - 256 for checkin KCM */
map = malloc(map_size*sizeof(*map));
if (map == NULL) {
- fprintf(stderr, "malloc of %d bytes failed.\n",
- (int)(map_size * sizeof(*map)));
+ fprintf(stderr, "%s: malloc of %d bytes failed.\n",
+ progname, (int)(map_size * sizeof(*map)));
close(fd);
return 1;
}
&& !aflag && file_size(fd, fname) == 0) {
break;
} else {
- sprintf(mbuf, "ioctl(XFS_IOC_GETBMAPX (iflags 0x%x) %s",
- map->bmv_iflags, fname);
- perror(mbuf);
+ fprintf(stderr, "%s: ioctl(XFS_IOC_GETBMAPX) "
+ "iflags=0x%x [\"%s\"]: %s\n",
+ progname, map->bmv_iflags, fname,
+ strerror(errno));
close(fd);
free(map);
return 1;
*/
i = ioctl(fd, aflag ? XFS_IOC_FSGETXATTRA : XFS_IOC_FSGETXATTR, &fsx);
if (i < 0) {
- sprintf(mbuf, "ioctl(XFS_IOC_FSGETXATTR%s) %s",
- aflag ? "A" : "", fname);
- perror(mbuf);
+ fprintf(stderr, "%s: ioctl(XFS_IOC_FSGETXATTR%s) "
+ "[\"%s\"]: %s\n", progname, aflag ? "A" : "",
+ fname, strerror(errno));
close(fd);
free(map);
return 1;
map_size = 2*(fsx.fsx_nextents+1);
map = realloc(map, map_size*sizeof(*map));
if (map == NULL) {
- fprintf(stderr, "cannot realloc %d bytes.\n",
- (int)(map_size * sizeof(*map)));
+ fprintf(stderr, "%s: cannot realloc %d bytes\n",
+ progname, (int)(map_size*sizeof(*map)));
close(fd);
return 1;
}
xfs \- layout of the XFS filesystem
.SH DESCRIPTION
An XFS filesystem can reside on a regular disk partition or on a
-logical volume (see
-.IR lvm (8)).
+logical volume.
An XFS filesystem has up to three parts:
a data section, a log section, and a realtime section.
Using the default
.IR mkfs.xfs (8)
options, the realtime section is absent, and
the log area is contained within the data section.
-For logical volume filesystems,
-the realtime section is optional,
-and the log section can be separate from the data section
+The log section can be either separate from the data section
or contained within it.
The filesystem sections are divided into a certain number of
.IR blocks ,
to locate free blocks and inodes;
these are located through the header structures.
.PP
-Each XFS filesystem is labeled with a unique
-universal identifier (UUID).
+Each XFS filesystem is labeled with a Universal Unique
+Identifier (UUID).
The UUID is stored in every allocation group header and
is used to help distinguish one XFS filesystem from another,
therefore you should avoid using
.I dd
or other block-by-block copying programs to copy XFS filesystems.
If two XFS filesystems on the same machine have the same UUID,
-.I xfsdump
-may become confused when doing incremental and resumed dumps
-(refer to
.IR xfsdump (8)
-for more details).
+may become confused when doing incremental and resumed dumps.
.I xfsdump
and
.I xfsrestore
are recommended for making copies of XFS filesystems.
+.SH OPERATIONS
+Some functionality specific to the XFS filesystem is accessible to
+applications through the Linux
+.IR ioctl (2)
+interface.
+These operations can be divided into two sections - operations
+that operate on individual files, and operations that operate on
+the filesystem itself.
+Care should be taken when issuing these XFS
+.I ioctl
+calls to ensure the target file descriptor does indeed represent a
+file from an XFS filesystem.
+The
+.IR fstatfs (2)
+system call can be used to determine whether or not an arbitrary
+file descriptor belongs to an XFS filesystem.
+
+.SS FILE OPERATIONS
+In order to effect an operation on an individual file, the descriptor
+argument passed to
+.I ioctl
+identifies the file being operated on.
+The third argument described below refers to the third argument of the
+.I ioctl
+system call (which is traditionally a
+.B "char *"
+or
+.BR "void *" ).
+All of the data structures and macros mentioned below are defined in the
+<xfs/xfs_fs.h> header file.
+.PP
+.nf
+.B XFS_IOC_FREESP
+.B XFS_IOC_FREESP64
+.B XFS_IOC_ALLOCSP
+.fi
+.PD 0
+.TP
+.B XFS_IOC_ALLOCSP64
+Alter storage space associated with a section of the ordinary
+file fildes. The section is specified by a variable of type
+.BR xfs_flock64_t ,
+pointed to by the third argument.
+The data type
+.B xfs_flock64_t
+contains the following members:
+.B l_whence
+is 0, 1, or 2 to indicate that the relative offset
+.B l_start
+will be measured from the start of the file, the current position, or
+the end of the file, respectively.
+.B l_start
+is the offset from the position specified in
+.BR l_whence .
+.B l_len
+is the size of the section. An
+.B l_len
+value of zero frees up to the end of the file; in this case, the end of
+file (i.e., file size) is set to the beginning of the section freed.
+Any data previously written into this section is no longer accessible.
+If the section specified is beyond the current end of file, the file
+is grown and filled with zeroes.
+The
+.B l_len
+field is currently ignored,
+and should be set to zero.
+
+.B XFS_IOC_FREESP
+and
+.BR XFS_IOC_FREESP64
+are identical, as are the
+.B XFS_IOC_ALLOCSP
+and
+.BR XFS_IOC_ALLOCSP64
+operations.
+
+.TP
+.B XFS_IOC_FSSETDM
+Set the di_dmevmask and di_dmstate fields in an XFS on-disk inode.
+The only legitimate values for these fields are those
+previously returned in the
+.B bs_dmevmask
+and
+.B bs_dmstate
+fields of the bulkstat structure.
+The data referred to by the third argument is a
+.BR "struct fsdmidata" .
+This structure's members are
+.B fsd_dmevmask
+and
+.BR fsd_dmstate .
+The di_dmevmask
+field is set to the value in
+.BR fsd_dmevmask .
+The di_dmstate field is set to the value in
+.BR fsd_dmstate .
+This command is restricted to root or to processes with device
+management capabilities.
+Its sole purpose is to allow backup and restore programs to restore the
+aforementioned critical on-disk inode fields.
+
+.TP
+.B XFS_IOC_DIOINFO
+Get information required to perform direct I/O on the specified file
+descriptor.
+Direct I/O is performed directly to and from a user's data buffer.
+Since the kernel's buffer cache is no longer between the two, the
+user's data buffer must conform to the same type of constraints as
+required for accessing a raw disk partition.
+The third argument points to a variable of type
+.BR "struct dioattr" ,
+which contains the following members:
+.B d_mem
+is the memory alignment requirement of the user's data buffer.
+.B d_miniosz
+specifies block size, minimum I/O request size, and I/O alignment.
+The size of all I/O requests must be a multiple of this amount and
+the value of the seek pointer at the time of the I/O request must
+also be an integer multiple of this amount.
+.B d_maxiosz
+is the maximum I/O request size which can be performed on the file
+descriptor.
+If an I/O request does not meet these constraints, the
+.IR read (2)
+or
+.IR write (2)
+will fail with EINVAL.
+All I/O requests are kept consistent with any data brought into
+the cache with an access through a non-direct I/O file descriptor.
+
+.TP
+.B XFS_IOC_FSGETXATTR
+Get extended attributes associated with files in XFS file systems.
+The third argument points to a variable of type
+.BR "struct fsxattr" ,
+whose fields include:
+.B fsx_xflags
+(extended flag bits),
+.B fsx_extsize
+(nominal extent size in file system blocks),
+.B fsx_nextents
+(number of data extents in the file),
+.B fsx_uuid
+(file unique id).
+Currently the only meaningful bits for the
+.B fsx_xflags
+field are bit 0 (value 1), which if set means the file is a realtime file,
+and bit 1 (value 2), which if set means the file has preallocated space.
+A
+.B fsx_extsize
+value returned indicates that a preferred extent size was previously
+set on the file, a
+.B fsx_extsize
+of zero indicates that the defaults for that filesystem will be used.
+
+.TP
+.B XFS_IOC_FSGETXATTRA
+Identical to
+.B XFS_IOC_FSGETXATTR
+except that the
+.B fsx_nextents
+field contains the number of attribute extents in the file.
+
+.TP
+.B XFS_IOC_FSSETXATTR
+Set extended attributes associated with files in XFS file systems.
+The third argument points to a variable of type
+.BR "struct fsxattr" ,
+but only the following fields are used in this call:
+.B fsx_xflags
+and
+.BR fsx_extsize .
+The
+.B fsx_xflags
+realtime file bit, and the file's extent size, may be changed only
+when the file is empty.
+
+.TP
+.B XFS_IOC_GETBMAP
+Get the block map for a segment of a file in an XFS file system.
+The third argument points to an arry of variables of type
+.BR "struct getbmap" .
+All sizes and offsets in the structure are in units of 512 bytes.
+The structure fields include:
+.B bmv_offset
+(file offset of segment),
+.B bmv_block
+(starting block of segment),
+.B bmv_length
+(length of segment),
+.B bmv_count
+(number of array entries, including the first), and
+.B bmv_entries
+(number of entries filled in).
+The first structure in the array is a header, and the remaining
+structures in the array contain block map information on return.
+The header controls iterative calls to the
+.B XFS_IOC_GETBMAP
+command.
+The caller fills in the
+.B bmv_offset
+and
+.B bmv_length
+fields of the header to indicate the area of interest in the file,
+and fills in the
+.B bmv_count
+field to indicate the length of the array.
+If the
+.B bmv_length
+value is set to -1 then the length of the interesting area is the rest
+of the file.
+On return from a call, the header is updated so that the command can be
+reused to obtain more information, without re-initializing the structures.
+Also on return, the
+.B bmv_entries
+field of the header is set to the number of array entries actually filled in.
+The non-header structures will be filled in with
+.BR bmv_offset ,
+.BR bmv_block ,
+and
+.BR bmv_length .
+If a region of the file has no blocks (is a hole in the file) then the
+.B bmv_block
+field is set to -1.
+
+.TP
+.B XFS_IOC_GETBMAPA
+Identical to
+.B XFS_IOC_GETBMAP
+except that information about the attribute fork of the file is returned.
+
+.PP
+.nf
+.B XFS_IOC_RESVSP
+.fi
+.TP
+.B XFS_IOC_RESVSP64
+This command is used to allocate space to a file.
+A range of bytes is specified using a pointer to a variable of type
+.B xfs_flock64_t
+in the third argument.
+The blocks are allocated, but not zeroed, and the file size does not change.
+If the XFS filesystem is configured to flag unwritten file extents,
+performance will be negatively affected when writing to preallocated space,
+since extra filesystem transactions are required to convert extent flags on
+the range of the file written.
+If
+.IR xfs_admin (8)
+reports unwritten=1, then the filesystem was made to flag unwritten extents.
+
+.PP
+.nf
+.B XFS_IOC_UNRESVSP
+.fi
+.TP
+.B XFS_IOC_UNRESVSP64
+This command is used to free space from a file.
+A range of bytes is specified using a pointer to a variable of type
+.B xfs_flock64_t
+in the third argument.
+Partial filesystem blocks are zeroed, and whole filesystem blocks are
+removed from the file. The file size does not change.
+
+.TP
+.B XFS_IOC_GETBIOSIZE
+This command gets information about the preferred buffered I/O
+size used by the system when performing buffered I/O (e.g.
+standard Unix non-direct I/O) to and from the file.
+The information is passed back in a structure of type
+.B "struct biosize"
+pointed to by the third argument.
+biosize lengths are expressed in log base 2.
+That is if the value is 14, then the true size is 2^14 (2 raised to
+the 14th power).
+The
+.B biosz_read
+field will contain the current value used by the system when reading
+from the file.
+Except at the end-of-file, the system will read from the file in
+multiples of this length.
+The
+.B biosz_write
+field will contain the current value used by the system when writing
+to the file.
+Except at the end-of-file, the system will write to the file in
+multiples of this length.
+The
+.B dfl_biosz_read
+and
+.B dfl_biosz_write
+will be set to the system default values for the opened file.
+The
+.B biosz_flags
+field will be set to 1 if the current read or write value has been
+explicitly set.
+
+.TP
+.B XFS_IOC_SETBIOSIZE
+This command the preferred buffered I/O size used by the system
+when performing buffered I/O (e.g. standard Unix non-direct
+I/O) to and from the file.
+The information is passed in a structure of type
+.B "struct biosize"
+pointed to by the third argument.
+Using smaller preferred I/O sizes can result in performance
+improvements if the file is typically accessed using small
+synchronous I/Os or if only a small amount of the file is accessed
+using small random I/Os, resulting in little or no use of the
+additional data read in near the random I/Os.
+
+To explicitly set the the preferred I/O sizes, the
+.B biosz_flags
+field should be set to zero and the
+.B biosz_read
+and
+.B biosz_write
+fields should be set to the log base 2 of the desired read and
+write lengths, respectively (e.g. 13 for 8K bytes, 14 for 16K
+bytes, 15 for 32K bytes, etc.). Valid values are 13-16
+inclusive for machines with a 4K byte pagesize and 14-16 for
+machines with a 16K byte pagesize. The specified read and
+write values must also result in lengths that are greater than
+or equal to the filesystem block size.
+The
+.B dfl_biosz_read
+and
+.B dfl_biosz_write
+fields are ignored.
+
+If biosizes have already been explicitly set due to a prior use
+of
+.BR XFS_IOC_SETBIOSIZE ,
+and the requested sizes are larger then the
+existing sizes, the
+.I ioctl
+call will return successfully and the
+system will use the smaller of the two sizes. However, if
+.B biosz_flags
+is set to 1, the system will use the new values
+regardless of whether the new sizes are larger or smaller than the old.
+
+To reset the biosize values to the defaults for the filesystem
+that the file resides in, the
+.B biosz_flags
+field should be set to 2.
+The remainder of the fields will be ignored in that case.
+
+Changes made by
+.B XFS_IOC_SETBIOSIZE
+are transient.
+The sizes are reset to the default values once the reference count on the
+file drops to zero (e.g. all open file descriptors to that file
+have been closed).
+See
+.I mount(8)
+for details on how to set the
+default biosize values for a filesystem.
+
+.PP
+.nf
+.B XFS_IOC_PATH_TO_HANDLE
+.B XFS_IOC_PATH_TO_FSHANDLE
+.B XFS_IOC_FD_TO_HANDLE
+.B XFS_IOC_OPEN_BY_HANDLE
+.B XFS_IOC_READLINK_BY_HANDLE
+.B XFS_IOC_ATTR_LIST_BY_HANDLE
+.B XFS_IOC_ATTR_MULTI_BY_HANDLE
+.fi
+.PD 0
+.TP
+.B XFS_IOC_FSSETDM_BY_HANDLE
+These are all interfaces that are used to implement various
+.I libhandle
+functions (see
+.IR fd_to_handle (3)).
+They are all subject to change and should not be called directly
+by applications.
+
+.SS FILESYSTEM OPERATIONS
+In order to effect one of the following operations, the file descriptor
+argument passed to
+.I ioctl
+can be any open file in the XFS filesystem in question.
+
+.PP
+.TP
+.B XFS_IOC_FSINUMBERS
+This interface is used to extract a list of valid inode numbers from an
+XFS filesystem.
+It is intended to be called iteratively, to obtain the entire set of inodes.
+The information is passed in and out via a structure of type
+.B xfs_fsop_bulkreq_t
+pointed to by the third argument.
+.B lastip
+is a pointer to a variable containing the last inode number returned,
+initially it should be zero.
+.B icount
+is the size of the array of structures specified by
+.BR ubuffer .
+.B ubuffer
+is the address of an array of structures, of type
+.BR xfs_inogrp_t .
+This structure has the following elements:
+.B xi_startino
+(starting inode number),
+.B xi_alloccount
+(count of bits set in xi_allocmask), and
+.B xi_allocmask
+(mask of allocated inodes in this group).
+The bitmask is 64 bits long, and the least significant bit corresponds to inode
+.B xi_startino.
+Each bit is set if the corresponding inode is in use.
+.B ocount
+is a pointer to a count of returned values, filled in by the call.
+An output
+.B ocount
+value of zero means that the inode table has been exhausted.
+
+.TP
+.B XFS_IOC_FSBULKSTAT
+This interface is used to extract inode information (stat
+information) "in bulk" from a filesystem. It is intended to
+be called iteratively, to obtain information about the entire
+set of inodes in a filesystem.
+The information is passed in and out via a structure of type
+.B xfs_fsop_bulkreq_t
+pointed to by the third argument.
+.B lastip
+is a pointer to a variable containing the last inode number returned,
+initially it should be zero.
+.B icount
+indicates the size of the array of structures specified by
+.B ubuffer.
+.B ubuffer
+is the address of an array of structures of type
+.BR xfs_bstat_t .
+Many of the elements in the structure are the same as for the stat
+structure.
+The structure has the following elements:
+.B bs_ino
+(inode number),
+.B bs_mode
+(type and mode),
+.B bs_nlink
+(number of links),
+.B bs_uid
+(user id),
+.B bs_gid
+(group id),
+.B bs_rdev
+(device value),
+.B bs_blksize
+(block size of the filesystem),
+.B bs_size
+(file size in bytes),
+.B bs_atime
+(access time),
+.B bs_mtime
+(modify time),
+.B bs_ctime
+(inode change time),
+.B bs_blocks
+(number of blocks used by the file),
+.B bs_xflags
+(extended flags),
+.B bs_extsize
+(extent size),
+.B bs_extents
+(number of extents),
+.B bs_gen
+(generation count),
+.B bs_projid
+(project id),
+.B bs_dmevmask
+(DMIG event mask),
+.B bs_dmstate
+(DMIG state information), and
+.B bs_aextents
+(attribute extent count).
+.B ocount
+is a pointer to a count of returned values, filled in by the call.
+An output
+.B ocount
+value of zero means that the inode table has been exhausted.
+
+.TP
+.B XFS_IOC_FSBULKSTAT_SINGLE
+This interface is a variant of the
+.B XFS_IOC_FSBULKSTAT
+interface, used to obtain information about a single inode.
+for an open file in the filesystem of interest.
+The same structure is used to pass information in and out of
+the kernel, except no output count parameter is used (should
+be initialized to zero).
+An error is returned if the inode number is invalid.
+
+.PP
+.nf
+.B XFS_IOC_THAW
+.B XFS_IOC_FREEZE
+.B XFS_IOC_GET_RESBLKS
+.B XFS_IOC_SET_RESBLKS
+.B XFS_IOC_FSGROWFSDATA
+.B XFS_IOC_FSGROWFSLOG
+.B XFS_IOC_FSGROWFSRT
+.fi
+.TP
+.B XFS_IOC_FSCOUNTS
+These interfaces are used to implement various filesystem internal
+operations on XFS filesystems.
+For
+.B XFS_IOC_FSGEOMETRY
+(get filesystem mkfs time information), the output structure is of type
+.BR xfs_fsop_geom_t .
+For
+.B XFS_FS_COUNTS
+(get filesystem dynamic global information), the output structure is of type
+.BR xfs_fsop_counts_t .
+The remainder of these operations will not be described further
+as they are not of general use to applications.
+
+.SH MOUNT OPTIONS
+Refer to the
+.IR mount (8)
+manual entry for descriptions of the individual XFS mount options.
+
.SH SEE ALSO
-fs(5),
+ioctl(2),
+fstatfs(2),
+mount(8),
mkfs.xfs(8),
-xfs_bmap(8),
-xfs_check(8),
-xfs_estimate(8),
-xfs_growfs(8),
-xfs_logprint(8),
-xfs_repair(8),
+xfs_admin(8),
xfsdump(8),
-xfsrestore(8),
-ioctl(2),
-lvm(8).
+xfsrestore(8).
projects / thirdparty / xfsprogs-dev.git / commitdiff
