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author | dfr <dfr@FreeBSD.org> | 1997-03-03 18:01:01 +0000 |
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committer | dfr <dfr@FreeBSD.org> | 1997-03-03 18:01:01 +0000 |
commit | 7e67e1e73230219ea55118f095cc1800faf2c534 (patch) | |
tree | e33dd16a7d9cf5ad26d4f75d4b2d3db1b3d2fdd9 /share/man/man9/VOP_RENAME.9 | |
parent | 6c38eceeb9c3076678e4763e02440823894d2323 (diff) | |
download | FreeBSD-src-7e67e1e73230219ea55118f095cc1800faf2c534.zip FreeBSD-src-7e67e1e73230219ea55118f095cc1800faf2c534.tar.gz |
This is the current draft of my filesystem manpages. Some files are
incomplete and some are just placeholders but I wanted to try to get
something at least into 2.2 on the grounds that what I have is a lot
better than nothing. I also wanted to commit something which documents
the interfaces in 2.2 before I start updating the documentation for 3.0.
This is a definite 2.2 candidate and is also relavent to 2.1 if people
still care about that branch.
Diffstat (limited to 'share/man/man9/VOP_RENAME.9')
-rw-r--r-- | share/man/man9/VOP_RENAME.9 | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/share/man/man9/VOP_RENAME.9 b/share/man/man9/VOP_RENAME.9 new file mode 100644 index 0000000..889c51c --- /dev/null +++ b/share/man/man9/VOP_RENAME.9 @@ -0,0 +1,306 @@ +.\" -*- nroff -*- +.\" +.\" Copyright (c) 1996 Doug Rabson +.\" +.\" All rights reserved. +.\" +.\" This program is free software. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, +.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $Id$ +.\" +.Dd July 24, 1996 +.Os +.Dt VOP_RENAME 9 +.Sh NAME +.Nm VOP_RENAME +.Nd rename a file +.Sh SYNOPSIS +.Fd #include <sys/vnode.h> +.Ft int +.Fn VOP_RENAME "struct vnode *fdvp" "struct vnode *fvp" "struct componentname *fcnp" "struct vnode *tdvp" "struct vnode *tvp" "struct componentname *tcnp" +.Sh DESCRIPTION +This renames a file and possibly changes its parent directory. +If the destination object exists, it will be removed first. +.Pp +Its arguments are: +.Bl -tag -width fdvp +.It Ar fdvp +the vnode of the old parent directory +.It Ar fvp +the vnode of the file to be renameed +.It Ar fcnp +pathname information about the file's current name +.It Ar tdvp +the vnode of the new parent directory +.It Ar tvp +the vnode of the target file (if it exists) +.It Ar tcnp +pathname information about the file's new name +.El +.Sh LOCKS +The destination directory and file (if it exists) should be locked on entry. +The source directory and file +will be released on exit. +The destination directory and file (if it exists) will be unlocked +and released on exit. +.Sh PSEUDOCODE +.Bd -literal +int +vop_rename(struct vnode *fdvp, struct vnode *fvp, struct componentname *fcnp, + struct vnode *tdvp, struct vnode *tvp, struct componentname *tcnp) +{ + int doingdirectory = 0; + int error = 0; + + /* + * Check for cross-device rename. + */ + if (fvp->v_mount != tdvp->v_mount) { + error = EXDEV; + abortit: + VOP_ABORTOP(tdvp, tcnp); + if (tdvp == tvp) + vrele(tdvp); + else + vput(tdvp); + if (tvp) + vput(tvp); + VOP_ABORTOP(fdvp, fcnp); + vrele(fdvp); + vrele(fvp); + return error; + } + + if (tvp exists and is immutable) { + error = EPERM; + goto abortit; + } + + /* + * Check if just deleting a link name. + */ + if (fvp == tvp) { + if (fvp->v_type == VDIR) { + error = EINVAL; + goto abortit; + } + + /* + * Release destination. + */ + VOP_ABORTOP(tdvp, tcnp); + vput(tdvp); + vput(tvp); + + /* + * Delete source. Pretty bizarre stuff. + */ + vrele(fdvp); + vrele(fvp); + fcnp->cn_flags &= ~MODMASK; + fcnp->cn_flags |= LOCKPARENT | LOCKLEAF; + fcnp->cn_nameiop = DELETE; + VREF(fdvp); + error = relookup(fdvp, &fvp, fcnp); + if (error == 0) + vrele(fdvp); + return VOP_REMOVE(fdvp, fvp, fcnp); + } + + if (fvp is immutable) { + error = EPERM; + goto abortit; + } + + error = VOP_LOCK(fvp); + if (error) + goto abortit; + + if (vp is a directory) { + /* + * Avoid ".", "..", and aliases of "." for obvious reasons. + */ + if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') + || fdvp == fvp + || ((fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT)) { + VOP_UNLOCK(fvp); + error = EINVAL; + goto abortit; + } + doingdirectory = 1; + } + vrele(fdvp); + + /* + * Bump link count on fvp while we are moving stuff around. If we + * crash before completing the work, the link count may be wrong + * but correctable. + */ + ...; + + /* + * If ".." must be changed (ie the directory gets a new + * parent) then the source directory must not be in the + * directory heirarchy above the target, as this would + * orphan everything below the source directory. Also + * the user must have write permission in the source so + * as to be able to change "..". + */ + error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc); + VOP_UNLOCK(fvp); + if (doingdirectory && fdvp != tdvp) { + /* + * Check for pathname conflict. + */ + ...; + } + + /* + * If the target doesn't exist, link the target to the source and + * unlink the source. Otherwise, rewrite the target directory to + * reference the source and remove the original entry. + */ + if (tvp == NULL) { + /* + * Account for ".." in new directory. + */ + if (doingdirectory && fdvp != tdvp) { + /* + * Increase link count of tdvp. + */ + ...; + } + + /* + * Add name in new directory. + */ + ...; + + if (error) { + if (doingdirectory && fdvp != tdvp) { + /* + * Decrease link count if tdvp. + */ + ...; + } + goto bad; + } + vput(tdvp); + } else { + /* + * Target must be empty if a directory and have no links + * to it. Also, ensure source and target are compatible + * (both directories, or both not directories). + */ + if (tvp is a directory) { + if (tvp is not empty) { + error = ENOTEMPTY; + goto bad; + } + if (!doingdirectory) { + error = ENOTDIR; + goto bad; + } + /* + * Update name cache since directory is going away. + */ + cache_purge(tdvp); + } else if (doingdirectory) { + error = ENOTDIR; + goto bad; + } + + /* + * Change name tcnp in tdvp to point at fvp. + */ + ...; + + /* + * If the target directory is in same directory as the source + * directory, decrement the link count on the parent of the + * target directory. This accounts for the fact that a + * directory links back to its parent with "..". + */ + if (doingdirectory && fdvp == tdvp) { + /* + * Decrement link count of tdvp. + */ + ...; + } + vput(tdvp); + + /* + * Decrement the link count of tvp since the directory no + * longer points at it. + */ + ...; + if (doingdirectory) { + /* + * Clean up the old directory tvp. + */ + ...; + } + vput(tvp); + } + + /* + * Unlink the source. If a directory was moved to a new parent, + * update its ".." entry. Gobs of ugly UFS code omitted here. + */ + ...; + +bad: + if (tvp) + vput(tvp); + vput(tdvp); +out: + if (VOP_LOCK(fvp) == 0) { + /* + * Decrement link count of fvp. + */ + ...; + vput(fvp); + } else + vrele(fvp); + + return error; +} +.Ed +.Sh ERRORS +.Bl -tag -width ENOTEMPTY +.It Bq Er EPERM +the file is immutable +.It Bq Er EXDEV +cross device move +.It Bq Er EINVAL +illegal directory rename +.It Bq Er ENOTDIR +attempt to rename a directory to a file or vice versa +.It Bq Er ENOTEMPTY +attempt to remove a directory which is not empty +.El +.Sh SEE ALSO +.Xr vnode 9 +.Sh AUTHORS +This man page was written by Doug Rabson. + |