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cgread1(3) [freebsd man page]

CGREAD(3)						   BSD Library Functions Manual 						 CGREAD(3)

NAME
cgread, cgread1, cgwrite1 -- read/write cylinder groups of UFS disks LIBRARY
UFS File System Access Library (libufs, -lufs) SYNOPSIS
#include <sys/param.h> #include <sys/mount.h> #include <ufs/ufs/ufsmount.h> #include <ufs/ufs/dinode.h> #include <ufs/ffs/fs.h> #include <libufs.h> int cgread(struct uufsd *disk); int cgread1(struct uufsd *disk, int c); int cgwrite1(struct uufsd *disk, int c); DESCRIPTION
The cgread() and cgread1() functions provide cylinder group reads for libufs(3) consumers. The cgread1() function reads from one cylinder group, specified by c into the d_cg field of a userland UFS disk structure. It sets the d_lcg field to the cylinder group number c. The cgread() function operates on sequential cylinder groups. Calling the cgread() function is equivalent to calling cgread1() with a cylin- der group specifier equivalent to the value of the current d_ccg field, and then incrementing the d_ccg field. The cgwrite1() function stores cylinder group specified by c from d_cg field of a userland UFS disk structure on disk. RETURN VALUES
Both functions return 0 if there are no more cylinder groups to read, 1 if there are more cylinder groups, and -1 on error. ERRORS
The function cgread() may fail and set errno for any of the errors specified for the library function bread(3). The function cgread1() has semantically identical failure conditions to those of cgread(). The function cgwrite1() may fail and set errno for any of the errors specified for the library function bwrite(3). SEE ALSO
bread(3), bwrite(3), libufs(3) HISTORY
These functions first appeared as part of libufs(3) in FreeBSD 5.1. AUTHORS
Juli Mallett <jmallett@FreeBSD.org> BSD
June 4, 2003 BSD

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UFS_DISK_CLOSE(3)					   BSD Library Functions Manual 					 UFS_DISK_CLOSE(3)

NAME
ufs_disk_close, ufs_disk_fillout, ufs_disk_fillout_blank, ufs_disk_write -- open and close userland UFS disks LIBRARY
UFS File System Access Library (libufs, -lufs) SYNOPSIS
#include <sys/param.h> #include <sys/mount.h> #include <ufs/ufs/ufsmount.h> #include <ufs/ufs/dinode.h> #include <ufs/ffs/fs.h> #include <libufs.h> int ufs_disk_close(struct uufsd *disk); int ufs_disk_fillout(struct uufsd *disk, const char *name); int ufs_disk_fillout_blank(struct uufsd *disk, const char *name); int ufs_disk_write(struct uufsd *disk); DESCRIPTION
The ufs_disk_close() function closes a disk and frees internal memory related to it. It does not free the disk structure. The ufs_disk_fillout() and ufs_disk_fillout_blank() functions open a disk specified by name and populate the structure pointed to by disk. The disk is opened read-only. The specified name may be either a mountpoint, a device name or a filesystem image. The ufs_disk_fillout() function assumes there is a valid superblock and will fail if not, whereas the ufs_disk_fillout_blank() function makes no assumptions of that sort. The ufs_disk_write() function attempts to re-open a disk as writable if it is not currently. ERRORS
The function ufs_disk_close() has no failure points. The function ufs_disk_fillout() may fail for any of the reasons ufs_disk_fillout_blank() might, as well as for any reason sbread(3) might. The ufs_disk_fillout_blank() may fail and set errno for any of the errors specified for the library functions open(2), strdup(3). Addition- ally, it may follow the libufs(3) error methodologies in situations where no device could be found to open. The function ufs_disk_write() may fail and set errno for any of the errors specified for the library functions open(2) and stat(2). Namely, it will fail if the disk in question may not be written to. SEE ALSO
open(2), getfsfile(3), libufs(3), sbread(3) HISTORY
These functions first appeared as part of libufs(3) in FreeBSD 5.0. AUTHORS
Juli Mallett <jmallett@FreeBSD.org> BSD
June 4, 2003 BSD
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