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kernel-ark/fs/gfs2/ops_inode.c
Steven Whitehouse 8497a46e17 [GFS2] Correct lock ordering in unlink 
This patch corrects the lock ordering in unlink to be the same as
that in the rest of GFS2, i.e. parent -> child -> rgrp.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:55:53 +01:00

1177 lines
27 KiB
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/utsname.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/lm_interface.h>
#include <asm/uaccess.h>
#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "bmap.h"
#include "dir.h"
#include "eaops.h"
#include "eattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "ops_dentry.h"
#include "ops_inode.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.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->intent.open.flags & O_EXCL))) {
gfs2_holder_uninit(ghs);
return PTR_ERR(inode);
}
inode = gfs2_lookupi(dir, &dentry->d_name, 0, nd);
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;
dentry->d_op = &gfs2_dops;
inode = gfs2_lookupi(dir, &dentry->d_name, 0, nd);
if (inode && IS_ERR(inode))
return ERR_PTR(PTR_ERR(inode));
if (inode)
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_m(2, ghs);
if (error)
goto out;
error = permission(dir, MAY_WRITE | MAY_EXEC, NULL);
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_di.di_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);
error = gfs2_quota_lock(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
goto out_alloc;
error = gfs2_quota_check(dip, dip->i_inode.i_uid, dip->i_inode.i_gid);
if (error)
goto out_gunlock_q;
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 +
al->al_rgd->rd_length +
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_m(2, ghs);
out:
gfs2_holder_uninit(ghs);
gfs2_holder_uninit(ghs + 1);
if (!error) {
atomic_inc(&inode->i_count);
d_instantiate(dentry, inode);
mark_inode_dirty(inode);
}
return error;
}
/**
* 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_rgrp;
error = gfs2_trans_begin(sdp, 2*RES_DINODE + RES_LEAF + RES_RG_BIT, 0);
if (error)
goto out_rgrp;
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);
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;
ip->i_di.di_size = 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;
ip->i_di.di_size = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);
ip->i_di.di_flags |= GFS2_DIF_JDATA;
ip->i_di.di_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);
struct qstr str;
gfs2_str2qstr(&str, ".");
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_qstr2dirent(&str, GFS2_DIRENT_SIZE(str.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);
gfs2_str2qstr(&str, "..");
dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1));
gfs2_qstr2dirent(&str, 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_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_m(3, ghs);
if (error)
goto out;
error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
if (error)
goto out_gunlock;
if (ip->i_di.di_entries < 2) {
if (gfs2_consist_inode(ip))
gfs2_dinode_print(ip);
error = -EIO;
goto out_gunlock;
}
if (ip->i_di.di_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_m(3, ghs);
out:
gfs2_holder_uninit(ghs);
gfs2_holder_uninit(ghs + 1);
gfs2_holder_uninit(ghs + 2);
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_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;
struct gfs2_rgrpd *nrgd;
unsigned int num_gh;
int dir_rename = 0;
int alloc_required;
unsigned int x;
int error;
if (ndentry->d_inode) {
nip = GFS2_I(ndentry->d_inode);
if (ip == nip)
return 0;
}
/* Make sure we aren't trying to move a dirctory into it's subdir */
if (S_ISDIR(ip->i_inode.i_mode) && odip != ndip) {
dir_rename = 1;
error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE, 0,
&r_gh);
if (error)
goto out;
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++);
}
error = gfs2_glock_nq_m(num_gh, ghs);
if (error)
goto out_uninit;
/* 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_di.di_entries < 2) {
if (gfs2_consist_inode(nip))
gfs2_dinode_print(nip);
error = -EIO;
goto out_gunlock;
}
if (nip->i_di.di_entries > 2) {
error = -ENOTEMPTY;
goto out_gunlock;
}
}
} else {
error = permission(ndir, MAY_WRITE | MAY_EXEC, NULL);
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_di.di_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 = permission(odentry->d_inode, MAY_WRITE, NULL);
if (error)
goto out_gunlock;
}
alloc_required = error = gfs2_diradd_alloc_required(ndir, &ndentry->d_name);
if (error < 0)
goto out_gunlock;
error = 0;
if (alloc_required) {
struct gfs2_alloc *al = gfs2_alloc_get(ndip);
error = gfs2_quota_lock(ndip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
goto out_alloc;
error = gfs2_quota_check(ndip, ndip->i_inode.i_uid, ndip->i_inode.i_gid);
if (error)
goto out_gunlock_q;
al->al_requested = sdp->sd_max_dirres;
error = gfs2_inplace_reserve(ndip);
if (error)
goto out_gunlock_q;
error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
al->al_rgd->rd_length +
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) {
struct qstr name;
gfs2_str2qstr(&name, "..");
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, &name, 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:
gfs2_glock_dq_m(num_gh, ghs);
out_uninit:
for (x = 0; x < num_gh; x++)
gfs2_holder_uninit(ghs + x);
out_gunlock_r:
if (dir_rename)
gfs2_glock_dq_uninit(&r_gh);
out:
return error;
}
/**
* gfs2_readlink - Read the value of a symlink
* @dentry: the symlink
* @buf: the buffer to read the symlink data into
* @size: the size of the buffer
*
* Returns: errno
*/
static int gfs2_readlink(struct dentry *dentry, char __user *user_buf,
int user_size)
{
struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
char array[GFS2_FAST_NAME_SIZE], *buf = array;
unsigned int len = GFS2_FAST_NAME_SIZE;
int error;
error = gfs2_readlinki(ip, &buf, &len);
if (error)
return error;
if (user_size > len - 1)
user_size = len - 1;
if (copy_to_user(user_buf, buf, user_size))
error = -EFAULT;
else
error = user_size;
if (buf != array)
kfree(buf);
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. It is optimised for symlinks
* under GFS2_FAST_NAME_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);
char array[GFS2_FAST_NAME_SIZE], *buf = array;
unsigned int len = GFS2_FAST_NAME_SIZE;
int error;
error = gfs2_readlinki(ip, &buf, &len);
if (!error) {
error = vfs_follow_link(nd, buf);
if (buf != array)
kfree(buf);
}
return ERR_PTR(error);
}
/**
* gfs2_permission -
* @inode:
* @mask:
* @nd: passed from Linux VFS, ignored by us
*
* This may be called from the VFS directly, or from within GFS2 with the
* inode locked, so we look to see if the glock is already locked and only
* lock the glock if its not already been done.
*
* Returns: errno
*/
static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder i_gh;
int error;
int unlock = 0;
if (gfs2_glock_is_locked_by_me(ip->i_gl) == 0) {
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
if (error)
return error;
unlock = 1;
}
error = generic_permission(inode, mask, gfs2_check_acl);
if (unlock)
gfs2_glock_dq_uninit(&i_gh);
return error;
}
static int setattr_size(struct inode *inode, struct iattr *attr)
{
struct gfs2_inode *ip = GFS2_I(inode);
int error;
if (attr->ia_size != ip->i_di.di_size) {
error = vmtruncate(inode, attr->ia_size);
if (error)
return error;
}
error = gfs2_truncatei(ip, attr->ia_size);
if (error && (inode->i_size != ip->i_di.di_size))
i_size_write(inode, ip->i_di.di_size);
return error;
}
static int setattr_chown(struct inode *inode, struct iattr *attr)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
struct buffer_head *dibh;
u32 ouid, ogid, nuid, ngid;
int error;
ouid = inode->i_uid;
ogid = inode->i_gid;
nuid = attr->ia_uid;
ngid = attr->ia_gid;
if (!(attr->ia_valid & ATTR_UID) || ouid == nuid)
ouid = nuid = NO_QUOTA_CHANGE;
if (!(attr->ia_valid & ATTR_GID) || ogid == ngid)
ogid = ngid = NO_QUOTA_CHANGE;
gfs2_alloc_get(ip);
error = gfs2_quota_lock(ip, nuid, ngid);
if (error)
goto out_alloc;
if (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) {
error = gfs2_quota_check(ip, nuid, ngid);
if (error)
goto out_gunlock_q;
}
error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_QUOTA, 0);
if (error)
goto out_gunlock_q;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
goto out_end_trans;
error = inode_setattr(inode, attr);
gfs2_assert_warn(sdp, !error);
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(ip, dibh->b_data);
brelse(dibh);
if (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) {
gfs2_quota_change(ip, -ip->i_di.di_blocks, ouid, ogid);
gfs2_quota_change(ip, ip->i_di.di_blocks, nuid, ngid);
}
out_end_trans:
gfs2_trans_end(sdp);
out_gunlock_q:
gfs2_quota_unlock(ip);
out_alloc:
gfs2_alloc_put(ip);
return error;
}
/**
* gfs2_setattr - Change attributes on an inode
* @dentry: The dentry which is changing
* @attr: The structure describing the change
*
* The VFS layer wants to change one or more of an inodes attributes. Write
* that change out to disk.
*
* Returns: errno
*/
static int gfs2_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder i_gh;
int error;
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
if (error)
return error;
error = -EPERM;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
goto out;
error = inode_change_ok(inode, attr);
if (error)
goto out;
if (attr->ia_valid & ATTR_SIZE)
error = setattr_size(inode, attr);
else if (attr->ia_valid & (ATTR_UID | ATTR_GID))
error = setattr_chown(inode, attr);
else if ((attr->ia_valid & ATTR_MODE) && IS_POSIXACL(inode))
error = gfs2_acl_chmod(ip, attr);
else
error = gfs2_setattr_simple(ip, attr);
out:
gfs2_glock_dq_uninit(&i_gh);
if (!error)
mark_inode_dirty(inode);
return error;
}
/**
* gfs2_getattr - Read out an inode's attributes
* @mnt: The vfsmount the inode is being accessed from
* @dentry: The dentry to stat
* @stat: The inode's stats
*
* This may be called from the VFS directly, or from within GFS2 with the
* inode locked, so we look to see if the glock is already locked and only
* lock the glock if its not already been done. Note that its the NFS
* readdirplus operation which causes this to be called (from filldir)
* with the glock already held.
*
* Returns: errno
*/
static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
int error;
int unlock = 0;
if (gfs2_glock_is_locked_by_me(ip->i_gl) == 0) {
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
if (error)
return error;
unlock = 1;
}
generic_fillattr(inode, stat);
if (unlock)
gfs2_glock_dq_uninit(&gh);
return 0;
}
static int gfs2_setxattr(struct dentry *dentry, const char *name,
const void *data, size_t size, int flags)
{
struct inode *inode = dentry->d_inode;
struct gfs2_ea_request er;
memset(&er, 0, sizeof(struct gfs2_ea_request));
er.er_type = gfs2_ea_name2type(name, &er.er_name);
if (er.er_type == GFS2_EATYPE_UNUSED)
return -EOPNOTSUPP;
er.er_data = (char *)data;
er.er_name_len = strlen(er.er_name);
er.er_data_len = size;
er.er_flags = flags;
gfs2_assert_warn(GFS2_SB(inode), !(er.er_flags & GFS2_ERF_MODE));
return gfs2_ea_set(GFS2_I(inode), &er);
}
static ssize_t gfs2_getxattr(struct dentry *dentry, const char *name,
void *data, size_t size)
{
struct gfs2_ea_request er;
memset(&er, 0, sizeof(struct gfs2_ea_request));
er.er_type = gfs2_ea_name2type(name, &er.er_name);
if (er.er_type == GFS2_EATYPE_UNUSED)
return -EOPNOTSUPP;
er.er_data = data;
er.er_name_len = strlen(er.er_name);
er.er_data_len = size;
return gfs2_ea_get(GFS2_I(dentry->d_inode), &er);
}
static ssize_t gfs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct gfs2_ea_request er;
memset(&er, 0, sizeof(struct gfs2_ea_request));
er.er_data = (size) ? buffer : NULL;
er.er_data_len = size;
return gfs2_ea_list(GFS2_I(dentry->d_inode), &er);
}
static int gfs2_removexattr(struct dentry *dentry, const char *name)
{
struct gfs2_ea_request er;
memset(&er, 0, sizeof(struct gfs2_ea_request));
er.er_type = gfs2_ea_name2type(name, &er.er_name);
if (er.er_type == GFS2_EATYPE_UNUSED)
return -EOPNOTSUPP;
er.er_name_len = strlen(er.er_name);
return gfs2_ea_remove(GFS2_I(dentry->d_inode), &er);
}
const struct inode_operations gfs2_file_iops = {
.permission = gfs2_permission,
.setattr = gfs2_setattr,
.getattr = gfs2_getattr,
.setxattr = gfs2_setxattr,
.getxattr = gfs2_getxattr,
.listxattr = gfs2_listxattr,
.removexattr = gfs2_removexattr,
};
const struct inode_operations gfs2_dev_iops = {
.permission = gfs2_permission,
.setattr = gfs2_setattr,
.getattr = gfs2_getattr,
.setxattr = gfs2_setxattr,
.getxattr = gfs2_getxattr,
.listxattr = gfs2_listxattr,
.removexattr = gfs2_removexattr,
};
const struct inode_operations gfs2_dir_iops = {
.create = gfs2_create,
.lookup = gfs2_lookup,
.link = gfs2_link,
.unlink = gfs2_unlink,
.symlink = gfs2_symlink,
.mkdir = gfs2_mkdir,
.rmdir = gfs2_rmdir,
.mknod = gfs2_mknod,
.rename = gfs2_rename,
.permission = gfs2_permission,
.setattr = gfs2_setattr,
.getattr = gfs2_getattr,
.setxattr = gfs2_setxattr,
.getxattr = gfs2_getxattr,
.listxattr = gfs2_listxattr,
.removexattr = gfs2_removexattr,
};
const struct inode_operations gfs2_symlink_iops = {
.readlink = gfs2_readlink,
.follow_link = gfs2_follow_link,
.permission = gfs2_permission,
.setattr = gfs2_setattr,
.getattr = gfs2_getattr,
.setxattr = gfs2_setxattr,
.getxattr = gfs2_getxattr,
.listxattr = gfs2_listxattr,
.removexattr = gfs2_removexattr,
};
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