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Diffstat (limited to 'lib/libufs/getinode.3')
| -rw-r--r-- | lib/libufs/getinode.3 | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/lib/libufs/getinode.3 b/lib/libufs/getinode.3 new file mode 100644 index 000000000000..1668e65551e5 --- /dev/null +++ b/lib/libufs/getinode.3 @@ -0,0 +1,129 @@ +.\" Author: Marshall Kirk McKusick <mckusick@freebsd.org> +.\" Date: January 19, 2018 +.\" Description: +.\" Manual page for libufs functions: +.\" getinode(3) +.\" putinode(3) +.\" +.\" This file is in the public domain. +.\" +.Dd September 2, 2020 +.Dt GETINODE 3 +.Os +.Sh NAME +.Nm getinode , putinode +.Nd fetch and store inodes on a UFS file system +.Sh LIBRARY +.Lb libufs +.Sh SYNOPSIS +.In ufs/ufs/dinode.h +.In ufs/ffs/fs.h +.In libufs.h +.Ft int +.Fn getinode "struct uufsd *disk" "union dinodep *dp" "ino_t inumber" +.Ft int +.Fn putinode "struct uufsd *disk" +.Sh DESCRIPTION +The +.Fn getinode +and +.Fn putinode +functions provide an inode fetch and store API for +.Xr libufs 3 +consumers. +They operate on a userland UFS disk structure. +The +.Fn getinode +function fetches the specified inode from the filesystem. +The +.Fn putinode +function stores the most recently fetched inode to the filesystem. +.Pp +The +.Va dinodep +union is defined as: +.Bd -literal -offset indent +union dinodep { + struct ufs1_dinode *dp1; + struct ufs2_dinode *dp2; +}; +.Ed +.Pp +Sample code to clear write permissions for inode number +.Fa inumber +stored on the filesystem described by +.Fa diskp . +.Bd -literal -offset indent +#include <sys/stat.h> +#include <err.h> + +#include <ufs/ufs/dinode.h> +#include <ufs/ffs/fs.h> +#include <libufs.h> + +void +clearwrite(struct uufsd *diskp, ino_t inumber) +{ + union dinodep dp; + + if (getinode(diskp, &dp, inumber) == -1) + err(1, "getinode: %s", diskp->d_error); + switch (diskp->d_ufs) { + case 1: /* UFS 1 filesystem */ + dp.dp1->di_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); + break; + case 2: /* UFS 2 filesystem */ + dp.dp2->di_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); + break; + default: + errx(1, "unknown filesystem type"); + } + if (putinode(diskp) == -1) + err(1, "putinode: %s", diskp->d_error); +} +.Ed +.Sh RETURN VALUES +The +.Fn getinode +and +.Fn putinode +functions return 0 on success, or \-1 in case of any error. +A string describing the error is stored in +.Fa diskp->d_error . +The global +.Fa errno +often provides additional information. +.Sh ERRORS +The function +.Fn getinode +may fail and set +.Va errno +for any of the errors specified for the library function +.Xr pread 2 . +It can also fail if the inode number is out of the range of inodes +in the filesystem. +.Pp +The function +.Fn putinode +may fail and set +.Va errno +for any of the errors specified for the library functions +.Xr ufs_disk_write 3 +or +.Xr pwrite 2 . +.Pp +Additionally both functions may follow the +.Xr libufs 3 +error methodologies in case of a device error. +.Sh SEE ALSO +.Xr pread 2 , +.Xr pwrite 2 , +.Xr libufs 3 , +.Xr ufs_disk_write 3 +.Sh HISTORY +These functions first appeared as part of +.Xr libufs 3 +in +.Fx 13.0 . +.Sh AUTHORS +.An Marshall Kirk McKusick Aq Mt mckusick@FreeBSD.org |