xref: /freebsd/share/man/man9/VOP_CREATE.9 (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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3.\" Copyright (c) 1996 Doug Rabson
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29.\" $FreeBSD$
30.\"
31.Dd July 24, 1996
32.Os
33.Dt VOP_CREATE 9
34.Sh NAME
35.Nm VOP_CREATE ,
36.Nm VOP_MKNOD ,
37.Nm VOP_MKDIR ,
38.Nm VOP_SYMLINK
39.Nd create a file, socket, fifo, device, directory or symlink
40.Sh SYNOPSIS
41.In sys/param.h
42.In sys/vnode.h
43.In sys/namei.h
44.Ft int
45.Fn VOP_CREATE "struct vnode *dvp" "struct vnode **vpp" "struct componentname *cnp" "struct vattr *vap"
46.Ft int
47.Fn VOP_MKNOD "struct vnode *dvp" "struct vnode **vpp" "struct componentname *cnp" "struct vattr *vap"
48.Ft int
49.Fn VOP_MKDIR "struct vnode *dvp" "struct vnode **vpp" "struct componentname *cnp" "struct vattr *vap"
50.Ft int
51.Fn VOP_SYMLINK "struct vnode *dvp" "struct vnode **vpp" "struct componentname *cnp" "struct vattr *vap" "char *target"
52.Sh DESCRIPTION
53These entry points create a new file, socket, fifo, device, directory or symlink
54in a given directory.
55.Pp
56The arguments are:
57.Bl -tag -width target
58.It Fa dvp
59the locked vnode of the directory
60.It Fa vpp
61the address of a variable where the resulting locked vnode should be stored
62.It Fa cnp
63the pathname component created
64.It Fa vap
65the attributes that the new object should be created with
66.It Fa target
67the pathname of the target of the symlink
68.El
69.Pp
70These entry points are called after
71.Xr VOP_LOOKUP 9
72when an object is being created.
73Normally,
74.Xr VOP_LOOKUP 9
75will have set the
76.Dv SAVENAME
77flag in
78.Fa cnp->cn_flags
79to keep the memory pointed to by
80.Fa cnp->cn_pnbuf
81valid.
82If an error is detected when creating the file,
83then this memory will be freed.
84If the file is created successfully, then it will be freed unless the
85.Dv SAVESTART
86flag is specified in
87.Fa cnp .
88.Sh LOCKS
89The directory,
90.Fa dvp
91will be locked on entry and must remain locked on return.
92If the call is successful, the new object will be returned locked.
93.Sh RETURN VALUES
94If successful, the vnode for the new object is placed in
95.Fa *vpp
96and zero is returned.
97Otherwise, an appropriate error is returned.
98.Sh PSEUDOCODE
99.Bd -literal
100int
101vop_create(struct vnode *dvp,
102	   struct vnode **vpp,
103	   struct componentname *cnp
104	   struct vattr *vap)
105{
106    int mode = MAKEIMODE(vap->va_type, vap->va_mode);
107    struct vnode *vp;
108    int error;
109
110    *vpp = NULL;
111    if ((mode & IFMT) == 0)
112	mode |= IFREG;
113
114    error = SOMEFS_VALLOC(dvp, mode, cnp->cn_cred, &vp);
115    if (error) {
116	free(cnp->cn_pnbuf, M_NAMEI);
117	vput(dvp);
118	return error;
119    }
120
121    /*
122     * Update the permissions for the new vnode, including
123     * copying the group from the directory.
124     */
125    ...;
126
127#ifdef QUOTA
128    /*
129     * Possibly check quota information.
130     */
131    ...;
132#endif
133
134    /*
135     * Enter new vnode in directory, taking care that the vnode
136     * hits the disk before the directory contents are changed.
137     */
138    error = ...;
139
140    if (error)
141	goto bad;
142
143    if ((cnp->cn_flags & SAVESTART) == 0)
144	free(cnp->cn_pnbuf, M_NAMEI);
145    vput(dvp);
146    *vpp = vp;
147
148    return 0;
149
150bad:
151    /*
152     * Write error occurred trying to update the inode
153     * or the directory so must deallocate the inode.
154     */
155    free(cnp->cn_pnbuf, M_NAMEI);
156    vput(vp);
157
158    /*
159     * Deallocate file system resources for vp.
160     */
161    ...;
162
163    vput(dvp);
164
165    return error;
166}
167.Ed
168.Sh ERRORS
169.Bl -tag -width Er
170.It Bq Er ENOSPC
171The file system is full.
172.It Bq Er EDQUOT
173The user's file system space or inode quota would be exceeded.
174.El
175.Sh SEE ALSO
176.Xr VOP_LOOKUP 9
177.Sh HISTORY
178The function
179.Nm
180appeared in
181.Bx 4.3 .
182.Sh SEE ALSO
183.Xr vnode 9
184.Sh AUTHORS
185This man page was written by
186.An Doug Rabson .
187