LFS_MARKV(2)

NAME
lfs_markv - rewrite disk blocks to new disk locations

LIBRARY
libc

SYNOPSIS
#include <sys/types.h>
#include <ufs/lfs/lfs.h>
int
lfs_markv(fsid_t *fsidp, BLOCK_INFO *blkiov, int blkcnt);

DESCRIPTION
lfs_markv() rewrites the blocks specified in blkiov to new disk locations, for the purposes of grouping them next to one another, or to move them out of a segment to clean it. All fields of the BLOCK_INFO structure must be filled in, except for bi_segcreate. If bi_daddr is not the correct current address for logical block bi_lbn of the file with inode number bi_inode, or if the file's version number does not match bi_version, the block will not be written to disk, but no error will be returned.

The fsidp argument contains the id of the filesystem to which the inodes and blocks belong. The bi_bp field contains bi_size bytes of data to be written into the appropriate block. If bi_lbn is specified as LFS_UNUSED_LBN, the inode itself will be rewritten.

The blkiov argument is an array of BLOCK_INFO structures (see below). The blkcnt argument determines the size of the blkiov array.

    typedef struct block_info {
        ino_t       bi_inode;     /* inode # */
        ufs_daddr_t bi_lbn;       /* logical block w/in file */
        ufs_daddr_t bi_daddr;     /* disk address of block */
        time_t      bi_segcreate; /* origin segment create time */
        int         bi_version;   /* file version number */
        void       *bi_bp;        /* data buffer */
        int         bi_size;      /* size of the block (if fragment) */
    } BLOCK_INFO;

RETURN VALUES
lfs_markv() returns 0 on success, or -1 on error.

ERRORS
An error return from lfs_markv() indicates:

[EFAULT]
    fsidp points outside the process's allocated address space.

[EINVAL]
    *fsidp does not specify a valid filesystem.

[EBUSY]
    One or more of the inodes whose blocks were to be written was locked, and its blocks were not rewritten.

SEE ALSO
lfs_segclean(2), lfs_segwait(2), lfs_cleanerd(8)

HISTORY
The lfs_markv() function call appeared in 4.4BSD.

BUGS
The functionality of lfs_markv() does not really belong in user space. Among other things it could be used to work around the SF_IMMUTABLE and SF_APPEND file flags (see chflags(2)).