Index: stable/12/lib/libufs/sbread.3 =================================================================== --- stable/12/lib/libufs/sbread.3 (revision 363055) +++ stable/12/lib/libufs/sbread.3 (revision 363056) @@ -1,145 +1,147 @@ .\" Author: Juli Mallett .\" Date: June 04, 2003 .\" Description: .\" Manual page for libufs functions: .\" sbget(3) .\" sbput(3) .\" sbread(3) .\" sbwrite(3) .\" .\" This file is in the public domain. .\" .\" $FreeBSD$ .\" .Dd January 19, 2018 .Dt SBREAD 3 .Os .Sh NAME .Nm sbget , sbput , sbread , sbwrite .Nd read and write superblocks of a UFS file system .Sh LIBRARY .Lb libufs .Sh SYNOPSIS .In sys/param.h .In sys/mount.h .In ufs/ufs/ufsmount.h .In ufs/ufs/dinode.h .In ufs/ffs/fs.h .In libufs.h .Ft int .Fn sbget "int devfd" "struct fs **fsp" "off_t sblockloc" .Ft int .Fn sbput "int devfd" "struct fs *fs" "int numaltwrite" .Ft int .Fn sbread "struct uufsd *disk" .Ft int .Fn sbwrite "struct uufsd *disk" "int all" .Sh DESCRIPTION The .Fn sbget and .Fn sbread functions provide superblock reads for .Xr libufs 3 consumers. The .Fn sbput and .Fn sbwrite functions provide superblock writes for .Xr libufs 3 consumers. .Pp The .Fn sbget function first allocates a buffer to hold the superblock. Using the .Va devfd file descriptor that references the filesystem disk, .Fn sbget reads the superblock located at the byte offset specified by .Va sblockloc into the allocated buffer. If successful, it returns a pointer to the buffer containing the superblock in .Va fsp . The .Fn sbget function is safe to use in threaded applications. .Pp The .Fn sbput function writes the superblock specified by .Va fs to the location from which it was read on the disk referenced by the .Va devfd file descriptor. Additionally, the .Fn sbput function will update the first .Va numaltwrite alternate superblock locations. To update all the alternate superblocks, specify a .Va numaltwrite value of .Va fs->fs_ncg . The .Fn sbput function is safe to use in threaded applications. Note that the .Fn sbput function needs to be called only if the superblock has been modified and the on-disk copy needs to be updated. .Pp The .Fn sbread function reads the standard filesystem superblock into the .Va d_sb , structure embedded in the given user-land UFS disk structure. .Pp The .Fn sbwrite function writes the superblock from the .Va d_sb , structure embedded in the given user-land UFS disk structure to the location from which it was read. Additionally, the .Fn sbwrite function will write to all the alternate superblock locations if the .Fa all value is non-zero. .Sh RETURN VALUES -.Rv -std sbget sbput sbread sbwrite -.Sh ERRORS +.Rv -std sbread sbwrite The .Fn sbget and +.Fn sbput +functions return the value 0 if successful; +otherwise they return one of the errors described below. +.Sh ERRORS +The errors returned by +.Fn sbget +and .Fn sbread -functions may fail and set -.Va errno -for any of the errors specified for the library function +include any of the errors specified for the library function .Xr bread 3 . -Additionally, it may follow the +Additionally, they may follow the .Xr libufs 3 error methodologies in situations where no usable superblock could be found. .Pp -The +The errors returned by .Fn sbput and .Fn sbwrite -functions may fail and set -.Va errno -for any of the errors specified for the library function +include any of the errors specified for the library function .Xr bwrite 3 . .Sh SEE ALSO .Xr bread 3 , .Xr bwrite 3 , .Xr libufs 3 .Sh HISTORY These functions first appeared as part of .Xr libufs 3 in .Fx 5.0 . .Sh AUTHORS .An Juli Mallett Aq Mt jmallett@FreeBSD.org Index: stable/12 =================================================================== --- stable/12 (revision 363055) +++ stable/12 (revision 363056) Property changes on: stable/12 ___________________________________________________________________ Modified: svn:mergeinfo ## -0,0 +0,1 ## Merged /head:r362560