lfs_markv(2) - NetBSD Manual Pages

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LFS_MARKV(2)              NetBSD System Calls Manual              LFS_MARKV(2)


NAME

     lfs_markv - rewrite disk blocks to new disk locations


LIBRARY

     Standard C Library (libc, -lc)


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 loca-
     tions, 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 struc-
     ture 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)).

NetBSD 2.0                       May 23, 2000                       NetBSD 2.0