linux-sg2042/fs/gfs2/dentry.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/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/namei.h>
#include <linux/crc32.h>
#include "gfs2.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "super.h"
#include "util.h"
#include "inode.h"
/**
* gfs2_drevalidate - Check directory lookup consistency
* @dentry: the mapping to check
* @flags: lookup flags
*
* Check to make sure the lookup necessary to arrive at this inode from its
* parent is still good.
*
* Returns: 1 if the dentry is ok, 0 if it isn't
*/
static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags)
{
struct dentry *parent;
struct gfs2_sbd *sdp;
struct gfs2_inode *dip;
struct inode *inode;
struct gfs2_holder d_gh;
struct gfs2_inode *ip = NULL;
int error;
int had_lock = 0;
if (flags & LOOKUP_RCU)
return -ECHILD;
parent = dget_parent(dentry);
sdp = GFS2_SB(parent->d_inode);
dip = GFS2_I(parent->d_inode);
inode = dentry->d_inode;
if (inode) {
if (is_bad_inode(inode))
goto invalid;
ip = GFS2_I(inode);
}
if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
goto valid;
had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
if (!had_lock) {
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
if (error)
goto fail;
}
error = gfs2_dir_check(parent->d_inode, &dentry->d_name, ip);
switch (error) {
case 0:
if (!inode)
goto invalid_gunlock;
break;
case -ENOENT:
if (!inode)
goto valid_gunlock;
goto invalid_gunlock;
default:
goto fail_gunlock;
}
valid_gunlock:
if (!had_lock)
gfs2_glock_dq_uninit(&d_gh);
valid:
dput(parent);
return 1;
invalid_gunlock:
if (!had_lock)
gfs2_glock_dq_uninit(&d_gh);
invalid:
if (inode && S_ISDIR(inode->i_mode)) {
if (have_submounts(dentry))
goto valid;
shrink_dcache_parent(dentry);
}
d_drop(dentry);
dput(parent);
return 0;
fail_gunlock:
gfs2_glock_dq_uninit(&d_gh);
fail:
dput(parent);
return 0;
}
static int gfs2_dhash(const struct dentry *dentry, const struct inode *inode,
struct qstr *str)
{
str->hash = gfs2_disk_hash(str->name, str->len);
return 0;
}
static int gfs2_dentry_delete(const struct dentry *dentry)
GFS2: free disk inode which is deleted by remote node -V2 this patch is for the same problem that Benjamin Marzinski fixes at commit b94a170e96dc416828af9d350ae2e34b70ae7347 quotation of the original problem: ---cut here--- When a file is deleted from a gfs2 filesystem on one node, a dcache entry for it may still exist on other nodes in the cluster. If this happens, gfs2 will be unable to free this file on disk. Because of this, it's possible to have a gfs2 filesystem with no files on it and no free space. With this patch, when a node receives a callback notifying it that the file is being deleted on another node, it schedules a new workqueue thread to remove the file's dcache entry. ---end cut--- after applying Benjamin's patch, I think there is still a case in which the disk inode remains even when "no space" is hit. the case is that when running d_prune_aliases() against the inode, there are one or more dentries(aliases) which have reference count number > 0. in this case the dentries won't be pruned. and even later, the reference count becomes to 0, the dentries can still be cached in memory. unfortunately, no callback come again, things come back to the state before the callback runs. thus the on disk inode remains there until in memoryinode is removed for some other reason(shrinking inode cache or unmount the volume..). this patch is to remove those dentries when their reference count becomes to 0 and the inode is deleted by remote node. for implementation, gfs2_dentry_delete() is added as dentry_operations.d_delete. the function returns true when the inode is deleted by remote node. in dput(), gfs2_dentry_delete() is called and since it returns true, the dentry is unhashed from dcache and then removed. when all dentries are removed, the in memory inode get removed so that the on disk inode is freed. Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-18 14:25:03 +08:00
{
struct gfs2_inode *ginode;
if (!dentry->d_inode)
return 0;
ginode = GFS2_I(dentry->d_inode);
if (!ginode->i_iopen_gh.gh_gl)
return 0;
if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags))
return 1;
return 0;
}
const struct dentry_operations gfs2_dops = {
.d_revalidate = gfs2_drevalidate,
.d_hash = gfs2_dhash,
GFS2: free disk inode which is deleted by remote node -V2 this patch is for the same problem that Benjamin Marzinski fixes at commit b94a170e96dc416828af9d350ae2e34b70ae7347 quotation of the original problem: ---cut here--- When a file is deleted from a gfs2 filesystem on one node, a dcache entry for it may still exist on other nodes in the cluster. If this happens, gfs2 will be unable to free this file on disk. Because of this, it's possible to have a gfs2 filesystem with no files on it and no free space. With this patch, when a node receives a callback notifying it that the file is being deleted on another node, it schedules a new workqueue thread to remove the file's dcache entry. ---end cut--- after applying Benjamin's patch, I think there is still a case in which the disk inode remains even when "no space" is hit. the case is that when running d_prune_aliases() against the inode, there are one or more dentries(aliases) which have reference count number > 0. in this case the dentries won't be pruned. and even later, the reference count becomes to 0, the dentries can still be cached in memory. unfortunately, no callback come again, things come back to the state before the callback runs. thus the on disk inode remains there until in memoryinode is removed for some other reason(shrinking inode cache or unmount the volume..). this patch is to remove those dentries when their reference count becomes to 0 and the inode is deleted by remote node. for implementation, gfs2_dentry_delete() is added as dentry_operations.d_delete. the function returns true when the inode is deleted by remote node. in dput(), gfs2_dentry_delete() is called and since it returns true, the dentry is unhashed from dcache and then removed. when all dentries are removed, the in memory inode get removed so that the on disk inode is freed. Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2009-08-18 14:25:03 +08:00
.d_delete = gfs2_dentry_delete,
};