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linux/fs/gfs2/ops_inode.c
Steven Whitehouse d82661d969 [GFS2] Streamline quota lock/check for no-quota case 
This patch streamlines the quota checking in the "no quota" case by
making the check inline in the calling function, thus reducing the
number of function calls. Eventually we might be able to remove the
checks from the gfs2_quota_lock() and gfs2_quota_check() functions, but
currently we can't as there are a very few places in the code which need
to call these functions directly still.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>
2008-03-31 10:41:36 +01:00

1183 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_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_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);
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 +
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);
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(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) == NULL) {
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);
struct gfs2_sbd *sdp = GFS2_SB(inode);
int error;
if (attr->ia_size != ip->i_di.di_size) {
error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
if (error)
return error;
error = vmtruncate(inode, attr->ia_size);
gfs2_trans_end(sdp);
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;
if (!gfs2_alloc_get(ip))
return -ENOMEM;
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) {
u64 blocks = gfs2_get_inode_blocks(&ip->i_inode);
gfs2_quota_change(ip, -blocks, ouid, ogid);
gfs2_quota_change(ip, 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) == NULL) {
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_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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