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ops_inode.c
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ops_inode.c
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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License version 2.
*/
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/namei.h>
#include <linux/mm.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/fiemap.h>
#include <asm/uaccess.h>
#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "bmap.h"
#include "dir.h"
#include "xattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
#include "super.h"
/**
* gfs2_create - Create a file
* @dir: The directory in which to create the file
* @dentry: The dentry of the new file
* @mode: The mode of the new file
*
* Returns: errno
*/
static int gfs2_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
struct gfs2_inode *dip = GFS2_I(dir);
struct gfs2_sbd *sdp = GFS2_SB(dir);
struct gfs2_holder ghs[2];
struct inode *inode;
gfs2_holder_init(dip->i_gl, 0, 0, ghs);
for (;;) {
inode = gfs2_createi(ghs, &dentry->d_name, S_IFREG | mode, 0);
if (!IS_ERR(inode)) {
gfs2_trans_end(sdp);
if (dip->i_alloc->al_rgd)
gfs2_inplace_release(dip);
gfs2_quota_unlock(dip);
gfs2_alloc_put(dip);
gfs2_glock_dq_uninit_m(2, ghs);
mark_inode_dirty(inode);
break;
} else if (PTR_ERR(inode) != -EEXIST ||
(nd && nd->flags & LOOKUP_EXCL)) {
gfs2_holder_uninit(ghs);
return PTR_ERR(inode);
}
inode = gfs2_lookupi(dir, &dentry->d_name, 0);
if (inode) {
if (!IS_ERR(inode)) {
gfs2_holder_uninit(ghs);
break;
} else {
gfs2_holder_uninit(ghs);
return PTR_ERR(inode);
}
}
}
d_instantiate(dentry, inode);
return 0;
}
/**
* gfs2_lookup - Look up a filename in a directory and return its inode
* @dir: The directory inode
* @dentry: The dentry of the new inode
* @nd: passed from Linux VFS, ignored by us
*
* Called by the VFS layer. Lock dir and call gfs2_lookupi()
*
* Returns: errno
*/
static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct inode *inode = NULL;
inode = gfs2_lookupi(dir, &dentry->d_name, 0);
if (inode && IS_ERR(inode))
return ERR_CAST(inode);
if (inode) {
struct gfs2_glock *gl = GFS2_I(inode)->i_gl;
struct gfs2_holder gh;
int error;
error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
if (error) {
iput(inode);
return ERR_PTR(error);
}
gfs2_glock_dq_uninit(&gh);
return d_splice_alias(inode, dentry);
}
d_add(dentry, inode);
return NULL;
}
/**
* gfs2_link - Link to a file
* @old_dentry: The inode to link
* @dir: Add link to this directory
* @dentry: The name of the link
*
* Link the inode in "old_dentry" into the directory "dir" with the
* name in "dentry".
*
* Returns: errno
*/
static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct gfs2_inode *dip = GFS2_I(dir);
struct gfs2_sbd *sdp = GFS2_SB(dir);
struct inode *inode = old_dentry->d_inode;
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder ghs[2];
int alloc_required;
int error;
if (S_ISDIR(inode->i_mode))
return -EPERM;
gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);
error = gfs2_glock_nq(ghs); /* parent */
if (error)
goto out_parent;
error = gfs2_glock_nq(ghs + 1); /* child */
if (error)
goto out_child;
error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC, 0);
if (error)
goto out_gunlock;
error = gfs2_dir_check(dir, &dentry->d_name, NULL);
switch (error) {
case -ENOENT:
break;
case 0:
error = -EEXIST;
default:
goto out_gunlock;
}
error = -EINVAL;
if (!dip->i_inode.i_nlink)
goto out_gunlock;
error = -EFBIG;
if (dip->i_entries == (u32)-1)
goto out_gunlock;
error = -EPERM;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
goto out_gunlock;
error = -EINVAL;
if (!ip->i_inode.i_nlink)
goto out_gunlock;
error = -EMLINK;
if (ip->i_inode.i_nlink == (u32)-1)
goto out_gunlock;
alloc_required = error = gfs2_diradd_alloc_required(dir, &dentry->d_name);
if (error < 0)
goto out_gunlock;
error = 0;
if (alloc_required) {
struct gfs2_alloc *al = gfs2_alloc_get(dip);
if (!al) {
error = -ENOMEM;
goto out_gunlock;
}
error = gfs2_quota_lock_check(dip);
if (error)
goto out_alloc;
al->al_requested = sdp->sd_max_dirres;
error = gfs2_inplace_reserve(dip);
if (error)
goto out_gunlock_q;
error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
gfs2_rg_blocks(al) +
2 * RES_DINODE + RES_STATFS +
RES_QUOTA, 0);
if (error)
goto out_ipres;
} else {
error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
if (error)
goto out_ipres;
}
error = gfs2_dir_add(dir, &dentry->d_name, ip, IF2DT(inode->i_mode));
if (error)
goto out_end_trans;
error = gfs2_change_nlink(ip, +1);
out_end_trans:
gfs2_trans_end(sdp);
out_ipres:
if (alloc_required)
gfs2_inplace_release(dip);
out_gunlock_q:
if (alloc_required)
gfs2_quota_unlock(dip);
out_alloc:
if (alloc_required)
gfs2_alloc_put(dip);
out_gunlock:
gfs2_glock_dq(ghs + 1);
out_child:
gfs2_glock_dq(ghs);
out_parent:
gfs2_holder_uninit(ghs);
gfs2_holder_uninit(ghs + 1);
if (!error) {
ihold(inode);
d_instantiate(dentry, inode);
mark_inode_dirty(inode);
}
return error;
}
/*
* gfs2_unlink_ok - check to see that a inode is still in a directory
* @dip: the directory
* @name: the name of the file
* @ip: the inode
*
* Assumes that the lock on (at least) @dip is held.
*
* Returns: 0 if the parent/child relationship is correct, errno if it isn't
*/
static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
const struct gfs2_inode *ip)
{
int error;
if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
return -EPERM;
if ((dip->i_inode.i_mode & S_ISVTX) &&
dip->i_inode.i_uid != current_fsuid() &&
ip->i_inode.i_uid != current_fsuid() && !capable(CAP_FOWNER))
return -EPERM;
if (IS_APPEND(&dip->i_inode))
return -EPERM;
error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0);
if (error)
return error;
error = gfs2_dir_check(&dip->i_inode, name, ip);
if (error)
return error;
return 0;
}
/**
* gfs2_unlink - Unlink a file
* @dir: The inode of the directory containing the file to unlink
* @dentry: The file itself
*
* Unlink a file. Call gfs2_unlinki()
*
* Returns: errno
*/
static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
{
struct gfs2_inode *dip = GFS2_I(dir);
struct gfs2_sbd *sdp = GFS2_SB(dir);
struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
struct gfs2_holder ghs[3];
struct gfs2_rgrpd *rgd;
struct gfs2_holder ri_gh;
int error;
error = gfs2_rindex_hold(sdp, &ri_gh);
if (error)
return error;
gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);
rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr);
gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2);
error = gfs2_glock_nq(ghs); /* parent */
if (error)
goto out_parent;
error = gfs2_glock_nq(ghs + 1); /* child */
if (error)
goto out_child;
error = gfs2_glock_nq(ghs + 2); /* rgrp */
if (error)
goto out_rgrp;
error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
if (error)
goto out_gunlock;
error = gfs2_trans_begin(sdp, 2*RES_DINODE + RES_LEAF + RES_RG_BIT, 0);
if (error)
goto out_gunlock;
error = gfs2_dir_del(dip, &dentry->d_name);
if (error)
goto out_end_trans;
error = gfs2_change_nlink(ip, -1);
out_end_trans:
gfs2_trans_end(sdp);
out_gunlock:
gfs2_glock_dq(ghs + 2);
out_rgrp:
gfs2_holder_uninit(ghs + 2);
gfs2_glock_dq(ghs + 1);
out_child:
gfs2_holder_uninit(ghs + 1);
gfs2_glock_dq(ghs);
out_parent:
gfs2_holder_uninit(ghs);
gfs2_glock_dq_uninit(&ri_gh);
return error;
}
/**
* gfs2_symlink - Create a symlink
* @dir: The directory to create the symlink in
* @dentry: The dentry to put the symlink in
* @symname: The thing which the link points to
*
* Returns: errno
*/
static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct gfs2_inode *dip = GFS2_I(dir), *ip;
struct gfs2_sbd *sdp = GFS2_SB(dir);
struct gfs2_holder ghs[2];
struct inode *inode;
struct buffer_head *dibh;
int size;
int error;
/* Must be stuffed with a null terminator for gfs2_follow_link() */
size = strlen(symname);
if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode) - 1)
return -ENAMETOOLONG;
gfs2_holder_init(dip->i_gl, 0, 0, ghs);
inode = gfs2_createi(ghs, &dentry->d_name, S_IFLNK | S_IRWXUGO, 0);
if (IS_ERR(inode)) {
gfs2_holder_uninit(ghs);
return PTR_ERR(inode);
}
ip = ghs[1].gh_gl->gl_object;
i_size_write(inode, size);
error = gfs2_meta_inode_buffer(ip, &dibh);
if (!gfs2_assert_withdraw(sdp, !error)) {
gfs2_dinode_out(ip, dibh->b_data);
memcpy(dibh->b_data + sizeof(struct gfs2_dinode), symname,
size);
brelse(dibh);
}
gfs2_trans_end(sdp);
if (dip->i_alloc->al_rgd)
gfs2_inplace_release(dip);
gfs2_quota_unlock(dip);
gfs2_alloc_put(dip);
gfs2_glock_dq_uninit_m(2, ghs);
d_instantiate(dentry, inode);
mark_inode_dirty(inode);
return 0;
}
/**
* gfs2_mkdir - Make a directory
* @dir: The parent directory of the new one
* @dentry: The dentry of the new directory
* @mode: The mode of the new directory
*
* Returns: errno
*/
static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct gfs2_inode *dip = GFS2_I(dir), *ip;
struct gfs2_sbd *sdp = GFS2_SB(dir);
struct gfs2_holder ghs[2];
struct inode *inode;
struct buffer_head *dibh;
int error;
gfs2_holder_init(dip->i_gl, 0, 0, ghs);
inode = gfs2_createi(ghs, &dentry->d_name, S_IFDIR | mode, 0);
if (IS_ERR(inode)) {
gfs2_holder_uninit(ghs);
return PTR_ERR(inode);
}
ip = ghs[1].gh_gl->gl_object;
ip->i_inode.i_nlink = 2;
i_size_write(inode, sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode));
ip->i_diskflags |= GFS2_DIF_JDATA;
ip->i_entries = 2;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (!gfs2_assert_withdraw(sdp, !error)) {
struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
struct gfs2_dirent *dent = (struct gfs2_dirent *)(di+1);
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_qstr2dirent(&gfs2_qdot, GFS2_DIRENT_SIZE(gfs2_qdot.len), dent);
dent->de_inum = di->di_num; /* already GFS2 endian */
dent->de_type = cpu_to_be16(DT_DIR);
di->di_entries = cpu_to_be32(1);
dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1));
gfs2_qstr2dirent(&gfs2_qdotdot, dibh->b_size - GFS2_DIRENT_SIZE(1) - sizeof(struct gfs2_dinode), dent);
gfs2_inum_out(dip, dent);
dent->de_type = cpu_to_be16(DT_DIR);
gfs2_dinode_out(ip, di);
brelse(dibh);
}
error = gfs2_change_nlink(dip, +1);
gfs2_assert_withdraw(sdp, !error); /* dip already pinned */
gfs2_trans_end(sdp);
if (dip->i_alloc->al_rgd)
gfs2_inplace_release(dip);
gfs2_quota_unlock(dip);
gfs2_alloc_put(dip);
gfs2_glock_dq_uninit_m(2, ghs);
d_instantiate(dentry, inode);
mark_inode_dirty(inode);
return 0;
}
/**
* gfs2_rmdiri - Remove a directory
* @dip: The parent directory of the directory to be removed
* @name: The name of the directory to be removed
* @ip: The GFS2 inode of the directory to be removed
*
* Assumes Glocks on dip and ip are held
*
* Returns: errno
*/
static int gfs2_rmdiri(struct gfs2_inode *dip, const struct qstr *name,
struct gfs2_inode *ip)
{
int error;
if (ip->i_entries != 2) {
if (gfs2_consist_inode(ip))
gfs2_dinode_print(ip);
return -EIO;
}
error = gfs2_dir_del(dip, name);
if (error)
return error;
error = gfs2_change_nlink(dip, -1);
if (error)
return error;
error = gfs2_dir_del(ip, &gfs2_qdot);
if (error)
return error;
error = gfs2_dir_del(ip, &gfs2_qdotdot);
if (error)
return error;
/* It looks odd, but it really should be done twice */
error = gfs2_change_nlink(ip, -1);
if (error)
return error;
error = gfs2_change_nlink(ip, -1);
if (error)
return error;
return error;
}
/**
* gfs2_rmdir - Remove a directory
* @dir: The parent directory of the directory to be removed
* @dentry: The dentry of the directory to remove
*
* Remove a directory. Call gfs2_rmdiri()
*
* Returns: errno
*/
static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
{
struct gfs2_inode *dip = GFS2_I(dir);
struct gfs2_sbd *sdp = GFS2_SB(dir);
struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
struct gfs2_holder ghs[3];
struct gfs2_rgrpd *rgd;
struct gfs2_holder ri_gh;
int error;
error = gfs2_rindex_hold(sdp, &ri_gh);
if (error)
return error;
gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);
rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr);
gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2);
error = gfs2_glock_nq(ghs); /* parent */
if (error)
goto out_parent;
error = gfs2_glock_nq(ghs + 1); /* child */
if (error)
goto out_child;
error = gfs2_glock_nq(ghs + 2); /* rgrp */
if (error)
goto out_rgrp;
error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
if (error)
goto out_gunlock;
if (ip->i_entries < 2) {
if (gfs2_consist_inode(ip))
gfs2_dinode_print(ip);
error = -EIO;
goto out_gunlock;
}
if (ip->i_entries > 2) {
error = -ENOTEMPTY;
goto out_gunlock;
}
error = gfs2_trans_begin(sdp, 2 * RES_DINODE + 3 * RES_LEAF + RES_RG_BIT, 0);
if (error)
goto out_gunlock;
error = gfs2_rmdiri(dip, &dentry->d_name, ip);
gfs2_trans_end(sdp);
out_gunlock:
gfs2_glock_dq(ghs + 2);
out_rgrp:
gfs2_holder_uninit(ghs + 2);
gfs2_glock_dq(ghs + 1);
out_child:
gfs2_holder_uninit(ghs + 1);
gfs2_glock_dq(ghs);
out_parent:
gfs2_holder_uninit(ghs);
gfs2_glock_dq_uninit(&ri_gh);
return error;
}
/**
* gfs2_mknod - Make a special file
* @dir: The directory in which the special file will reside
* @dentry: The dentry of the special file
* @mode: The mode of the special file
* @rdev: The device specification of the special file
*
*/
static int gfs2_mknod(struct inode *dir, struct dentry *dentry, int mode,
dev_t dev)
{
struct gfs2_inode *dip = GFS2_I(dir);
struct gfs2_sbd *sdp = GFS2_SB(dir);
struct gfs2_holder ghs[2];
struct inode *inode;
gfs2_holder_init(dip->i_gl, 0, 0, ghs);
inode = gfs2_createi(ghs, &dentry->d_name, mode, dev);
if (IS_ERR(inode)) {
gfs2_holder_uninit(ghs);
return PTR_ERR(inode);
}
gfs2_trans_end(sdp);
if (dip->i_alloc->al_rgd)
gfs2_inplace_release(dip);
gfs2_quota_unlock(dip);
gfs2_alloc_put(dip);
gfs2_glock_dq_uninit_m(2, ghs);
d_instantiate(dentry, inode);
mark_inode_dirty(inode);
return 0;
}
/*
* gfs2_ok_to_move - check if it's ok to move a directory to another directory
* @this: move this
* @to: to here
*
* Follow @to back to the root and make sure we don't encounter @this
* Assumes we already hold the rename lock.
*
* Returns: errno
*/
static int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
{
struct inode *dir = &to->i_inode;
struct super_block *sb = dir->i_sb;
struct inode *tmp;
int error = 0;
igrab(dir);
for (;;) {
if (dir == &this->i_inode) {
error = -EINVAL;
break;
}
if (dir == sb->s_root->d_inode) {
error = 0;
break;
}
tmp = gfs2_lookupi(dir, &gfs2_qdotdot, 1);
if (IS_ERR(tmp)) {
error = PTR_ERR(tmp);
break;
}
iput(dir);
dir = tmp;
}
iput(dir);
return error;
}
/**
* gfs2_rename - Rename a file
* @odir: Parent directory of old file name
* @odentry: The old dentry of the file
* @ndir: Parent directory of new file name
* @ndentry: The new dentry of the file
*
* Returns: errno
*/
static int gfs2_rename(struct inode *odir, struct dentry *odentry,
struct inode *ndir, struct dentry *ndentry)
{
struct gfs2_inode *odip = GFS2_I(odir);
struct gfs2_inode *ndip = GFS2_I(ndir);
struct gfs2_inode *ip = GFS2_I(odentry->d_inode);
struct gfs2_inode *nip = NULL;
struct gfs2_sbd *sdp = GFS2_SB(odir);
struct gfs2_holder ghs[5], r_gh = { .gh_gl = NULL, }, ri_gh;
struct gfs2_rgrpd *nrgd;
unsigned int num_gh;
int dir_rename = 0;
int alloc_required = 0;
unsigned int x;
int error;
if (ndentry->d_inode) {
nip = GFS2_I(ndentry->d_inode);
if (ip == nip)
return 0;
}
error = gfs2_rindex_hold(sdp, &ri_gh);
if (error)
return error;
if (odip != ndip) {
error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE,
0, &r_gh);
if (error)
goto out;
if (S_ISDIR(ip->i_inode.i_mode)) {
dir_rename = 1;
/* don't move a dirctory into it's subdir */
error = gfs2_ok_to_move(ip, ndip);
if (error)
goto out_gunlock_r;
}
}
num_gh = 1;
gfs2_holder_init(odip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
if (odip != ndip) {
gfs2_holder_init(ndip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
num_gh++;
}
gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
num_gh++;
if (nip) {
gfs2_holder_init(nip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
num_gh++;
/* grab the resource lock for unlink flag twiddling
* this is the case of the target file already existing
* so we unlink before doing the rename
*/
nrgd = gfs2_blk2rgrpd(sdp, nip->i_no_addr);
if (nrgd)
gfs2_holder_init(nrgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh++);
}
for (x = 0; x < num_gh; x++) {
error = gfs2_glock_nq(ghs + x);
if (error)
goto out_gunlock;
}
/* Check out the old directory */
error = gfs2_unlink_ok(odip, &odentry->d_name, ip);
if (error)
goto out_gunlock;
/* Check out the new directory */
if (nip) {
error = gfs2_unlink_ok(ndip, &ndentry->d_name, nip);
if (error)
goto out_gunlock;
if (S_ISDIR(nip->i_inode.i_mode)) {
if (nip->i_entries < 2) {
if (gfs2_consist_inode(nip))
gfs2_dinode_print(nip);
error = -EIO;
goto out_gunlock;
}
if (nip->i_entries > 2) {
error = -ENOTEMPTY;
goto out_gunlock;
}
}
} else {
error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC, 0);
if (error)
goto out_gunlock;
error = gfs2_dir_check(ndir, &ndentry->d_name, NULL);
switch (error) {
case -ENOENT:
error = 0;
break;
case 0:
error = -EEXIST;
default:
goto out_gunlock;
};
if (odip != ndip) {
if (!ndip->i_inode.i_nlink) {
error = -EINVAL;
goto out_gunlock;
}
if (ndip->i_entries == (u32)-1) {
error = -EFBIG;
goto out_gunlock;
}
if (S_ISDIR(ip->i_inode.i_mode) &&
ndip->i_inode.i_nlink == (u32)-1) {
error = -EMLINK;
goto out_gunlock;
}
}
}
/* Check out the dir to be renamed */
if (dir_rename) {
error = gfs2_permission(odentry->d_inode, MAY_WRITE, 0);
if (error)
goto out_gunlock;
}
if (nip == NULL)
alloc_required = gfs2_diradd_alloc_required(ndir, &ndentry->d_name);
error = alloc_required;
if (error < 0)
goto out_gunlock;
error = 0;
if (alloc_required) {
struct gfs2_alloc *al = gfs2_alloc_get(ndip);
if (!al) {
error = -ENOMEM;
goto out_gunlock;
}
error = gfs2_quota_lock_check(ndip);
if (error)
goto out_alloc;
al->al_requested = sdp->sd_max_dirres;
error = gfs2_inplace_reserve_ri(ndip);
if (error)
goto out_gunlock_q;
error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
gfs2_rg_blocks(al) +
4 * RES_DINODE + 4 * RES_LEAF +
RES_STATFS + RES_QUOTA + 4, 0);
if (error)
goto out_ipreserv;
} else {
error = gfs2_trans_begin(sdp, 4 * RES_DINODE +
5 * RES_LEAF + 4, 0);
if (error)
goto out_gunlock;
}
/* Remove the target file, if it exists */
if (nip) {
if (S_ISDIR(nip->i_inode.i_mode))
error = gfs2_rmdiri(ndip, &ndentry->d_name, nip);
else {
error = gfs2_dir_del(ndip, &ndentry->d_name);
if (error)
goto out_end_trans;
error = gfs2_change_nlink(nip, -1);
}
if (error)
goto out_end_trans;
}
if (dir_rename) {
error = gfs2_change_nlink(ndip, +1);
if (error)
goto out_end_trans;
error = gfs2_change_nlink(odip, -1);
if (error)
goto out_end_trans;
error = gfs2_dir_mvino(ip, &gfs2_qdotdot, ndip, DT_DIR);
if (error)
goto out_end_trans;
} else {
struct buffer_head *dibh;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
goto out_end_trans;
ip->i_inode.i_ctime = CURRENT_TIME;
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(ip, dibh->b_data);
brelse(dibh);
}
error = gfs2_dir_del(odip, &odentry->d_name);
if (error)
goto out_end_trans;
error = gfs2_dir_add(ndir, &ndentry->d_name, ip, IF2DT(ip->i_inode.i_mode));
if (error)
goto out_end_trans;
out_end_trans:
gfs2_trans_end(sdp);
out_ipreserv:
if (alloc_required)
gfs2_inplace_release(ndip);
out_gunlock_q:
if (alloc_required)
gfs2_quota_unlock(ndip);
out_alloc:
if (alloc_required)
gfs2_alloc_put(ndip);
out_gunlock:
while (x--) {
gfs2_glock_dq(ghs + x);
gfs2_holder_uninit(ghs + x);
}
out_gunlock_r:
if (r_gh.gh_gl)
gfs2_glock_dq_uninit(&r_gh);
out:
gfs2_glock_dq_uninit(&ri_gh);
return error;
}
/**
* gfs2_follow_link - Follow a symbolic link
* @dentry: The dentry of the link
* @nd: Data that we pass to vfs_follow_link()
*
* This can handle symlinks of any size.
*
* Returns: 0 on success or error code
*/
static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
struct gfs2_holder i_gh;
struct buffer_head *dibh;
unsigned int x, size;
char *buf;
int error;
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
error = gfs2_glock_nq(&i_gh);
if (error) {
gfs2_holder_uninit(&i_gh);
nd_set_link(nd, ERR_PTR(error));
return NULL;
}
size = (unsigned int)i_size_read(&ip->i_inode);
if (size == 0) {
gfs2_consist_inode(ip);
buf = ERR_PTR(-EIO);
goto out;
}