1 .\" Copyright (c) 1996 Doug Rabson
3 .\" All rights reserved.
5 .\" This program is free software.
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27 .\" $FreeBSD: src/share/man/man9/VOP_READDIR.9,v 1.6.2.1 2001/12/17 11:30:18 ru Exp $
28 .\" $DragonFly: src/share/man/man9/VOP_READDIR.9,v 1.6 2008/05/02 02:05:06 swildner Exp $
35 .Nd read contents of a directory
41 .Fn VOP_READDIR "struct vnode *vp" "struct uio *uio" "struct ucred *cred" "int *eofflag" "int *ncookies" "u_long **cookies"
43 Read directory entries.
44 .Bl -tag -width ncookies
46 the vnode of the directory
48 where to read the directory contents
50 the caller's credentials
52 return end of file status (NULL if not wanted)
54 number of directory cookies generated for NFS (NULL if not wanted)
56 directory seek cookies generated for NFS (NULL if not wanted)
58 The directory contents are read into
60 structures. If the on-disc data structures differ from this then they
63 The directory should be locked on entry and will still be locked on exit.
65 Zero is returned on success, otherwise an error code is returned.
67 If this is called from the NFS server, the extra arguments
75 should be set to TRUE if the end of the directory is reached while
77 The directory seek cookies are returned to the NFS client and may be used
78 later to restart a directory read part way through the directory.
79 There should be one cookie returned per directory entry. The value of
80 the cookie should be the offset within the directory where the on-disc
81 version of the appropriate directory entry starts.
82 Memory for the cookies should be allocated using:
85 *ncookies = number of entries read;
87 kmalloc(*ncookies * sizeof(u_int), M_TEMP, M_WAITOK);
92 vop_readdir(struct vnode *vp, struct uio *uio, struct ucred *cred,
93 int *eofflag, int *ncookies, u_int **cookies)
99 * Remember the original offset to use later in generating cookies.
101 off = uio->uio_offset;
104 * Read directory contents starting at uio->uio_offset into buffer
109 if (!error && ncookies != NULL) {
110 struct dirent *dpStart;
111 struct dirent *dpEnd;
117 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
118 panic("vop_readdir: unexpected uio from NFS server");
121 * Parse the stuff just read into the uio.
123 dpStart = (struct dirent *)
124 (uio->uio_iov->iov_base - (uio->uio_offset - off));
125 dpEnd = (struct dirent *) uio->uio_iov->iov_base;
128 * Count number of entries.
130 for (dp = dpStart, count = 0;
132 dp = (struct dirent *)((caddr_t) dp + dp->d_reclen))
135 cookiebuf = (u_int *) kmalloc(count * sizeof(u_int), M_TEMP, M_WAITOK);
136 for (dp = dpStart; cookiep = cookiebuf;
138 dp = (struct dirent *)((caddr_t) dp + dp->d_reclen)) {
140 *cookiep++ = (u_int) off;
143 *cookies = cookiebuf;
146 if (eofflag && uio->uio_offset is past the end of the directory) {
156 attempt to read from an illegal offset in the directory
158 a read error occurred while reading the directory
163 This man page was written by