linux/fs/gfs2/glops.c
Benjamin Marzinski 2e60d7683c GFS2: update freeze code to use freeze/thaw_super on all nodes
The current gfs2 freezing code is considerably more complicated than it
should be because it doesn't use the vfs freezing code on any node except
the one that begins the freeze.  This is because it needs to acquire a
cluster glock before calling the vfs code to prevent a deadlock, and
without the new freeze_super and thaw_super hooks, that was impossible. To
deal with the issue, gfs2 had to do some hacky locking tricks to make sure
that a frozen node couldn't be holding on a lock it needed to do the
unfreeze ioctl.

This patch makes use of the new hooks to simply the gfs2 locking code. Now,
all the nodes in the cluster freeze and thaw in exactly the same way. Every
node in the cluster caches the freeze glock in the shared state.  The new
freeze_super hook allows the freezing node to grab this freeze glock in
the exclusive state without first calling the vfs freeze_super function.
All the nodes in the cluster see this lock change, and call the vfs
freeze_super function. The vfs locking code guarantees that the nodes can't
get stuck holding the glocks necessary to unfreeze the system.  To
unfreeze, the freezing node uses the new thaw_super hook to drop the freeze
glock. Again, all the nodes notice this, reacquire the glock in shared mode
and call the vfs thaw_super function.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-11-17 10:36:39 +00:00

617 lines
16 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2008 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/bio.h>
#include <linux/posix_acl.h>
#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "log.h"
#include "meta_io.h"
#include "recovery.h"
#include "rgrp.h"
#include "util.h"
#include "trans.h"
#include "dir.h"
struct workqueue_struct *gfs2_freeze_wq;
static void gfs2_ail_error(struct gfs2_glock *gl, const struct buffer_head *bh)
{
fs_err(gl->gl_sbd, "AIL buffer %p: blocknr %llu state 0x%08lx mapping %p page state 0x%lx\n",
bh, (unsigned long long)bh->b_blocknr, bh->b_state,
bh->b_page->mapping, bh->b_page->flags);
fs_err(gl->gl_sbd, "AIL glock %u:%llu mapping %p\n",
gl->gl_name.ln_type, gl->gl_name.ln_number,
gfs2_glock2aspace(gl));
gfs2_lm_withdraw(gl->gl_sbd, "AIL error\n");
}
/**
* __gfs2_ail_flush - remove all buffers for a given lock from the AIL
* @gl: the glock
* @fsync: set when called from fsync (not all buffers will be clean)
*
* None of the buffers should be dirty, locked, or pinned.
*/
static void __gfs2_ail_flush(struct gfs2_glock *gl, bool fsync,
unsigned int nr_revokes)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct list_head *head = &gl->gl_ail_list;
struct gfs2_bufdata *bd, *tmp;
struct buffer_head *bh;
const unsigned long b_state = (1UL << BH_Dirty)|(1UL << BH_Pinned)|(1UL << BH_Lock);
gfs2_log_lock(sdp);
spin_lock(&sdp->sd_ail_lock);
list_for_each_entry_safe_reverse(bd, tmp, head, bd_ail_gl_list) {
if (nr_revokes == 0)
break;
bh = bd->bd_bh;
if (bh->b_state & b_state) {
if (fsync)
continue;
gfs2_ail_error(gl, bh);
}
gfs2_trans_add_revoke(sdp, bd);
nr_revokes--;
}
GLOCK_BUG_ON(gl, !fsync && atomic_read(&gl->gl_ail_count));
spin_unlock(&sdp->sd_ail_lock);
gfs2_log_unlock(sdp);
}
static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_trans tr;
memset(&tr, 0, sizeof(tr));
INIT_LIST_HEAD(&tr.tr_buf);
INIT_LIST_HEAD(&tr.tr_databuf);
tr.tr_revokes = atomic_read(&gl->gl_ail_count);
if (!tr.tr_revokes)
return;
/* A shortened, inline version of gfs2_trans_begin()
* tr->alloced is not set since the transaction structure is
* on the stack */
tr.tr_reserved = 1 + gfs2_struct2blk(sdp, tr.tr_revokes, sizeof(u64));
tr.tr_ip = _RET_IP_;
if (gfs2_log_reserve(sdp, tr.tr_reserved) < 0)
return;
WARN_ON_ONCE(current->journal_info);
current->journal_info = &tr;
__gfs2_ail_flush(gl, 0, tr.tr_revokes);
gfs2_trans_end(sdp);
gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
}
void gfs2_ail_flush(struct gfs2_glock *gl, bool fsync)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
unsigned int revokes = atomic_read(&gl->gl_ail_count);
unsigned int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
int ret;
if (!revokes)
return;
while (revokes > max_revokes)
max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64);
ret = gfs2_trans_begin(sdp, 0, max_revokes);
if (ret)
return;
__gfs2_ail_flush(gl, fsync, max_revokes);
gfs2_trans_end(sdp);
gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
}
/**
* rgrp_go_sync - sync out the metadata for this glock
* @gl: the glock
*
* Called when demoting or unlocking an EX glock. We must flush
* to disk all dirty buffers/pages relating to this glock, and must not
* not return to caller to demote/unlock the glock until I/O is complete.
*/
static void rgrp_go_sync(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct address_space *mapping = &sdp->sd_aspace;
struct gfs2_rgrpd *rgd;
int error;
if (!test_and_clear_bit(GLF_DIRTY, &gl->gl_flags))
return;
GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
gfs2_log_flush(sdp, gl, NORMAL_FLUSH);
filemap_fdatawrite_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
error = filemap_fdatawait_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
mapping_set_error(mapping, error);
gfs2_ail_empty_gl(gl);
spin_lock(&gl->gl_spin);
rgd = gl->gl_object;
if (rgd)
gfs2_free_clones(rgd);
spin_unlock(&gl->gl_spin);
}
/**
* rgrp_go_inval - invalidate the metadata for this glock
* @gl: the glock
* @flags:
*
* We never used LM_ST_DEFERRED with resource groups, so that we
* should always see the metadata flag set here.
*
*/
static void rgrp_go_inval(struct gfs2_glock *gl, int flags)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct address_space *mapping = &sdp->sd_aspace;
WARN_ON_ONCE(!(flags & DIO_METADATA));
gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
truncate_inode_pages_range(mapping, gl->gl_vm.start, gl->gl_vm.end);
if (gl->gl_object) {
struct gfs2_rgrpd *rgd = (struct gfs2_rgrpd *)gl->gl_object;
rgd->rd_flags &= ~GFS2_RDF_UPTODATE;
}
}
/**
* inode_go_sync - Sync the dirty data and/or metadata for an inode glock
* @gl: the glock protecting the inode
*
*/
static void inode_go_sync(struct gfs2_glock *gl)
{
struct gfs2_inode *ip = gl->gl_object;
struct address_space *metamapping = gfs2_glock2aspace(gl);
int error;
if (ip && !S_ISREG(ip->i_inode.i_mode))
ip = NULL;
if (ip) {
if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
unmap_shared_mapping_range(ip->i_inode.i_mapping, 0, 0);
inode_dio_wait(&ip->i_inode);
}
if (!test_and_clear_bit(GLF_DIRTY, &gl->gl_flags))
return;
GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);
gfs2_log_flush(gl->gl_sbd, gl, NORMAL_FLUSH);
filemap_fdatawrite(metamapping);
if (ip) {
struct address_space *mapping = ip->i_inode.i_mapping;
filemap_fdatawrite(mapping);
error = filemap_fdatawait(mapping);
mapping_set_error(mapping, error);
}
error = filemap_fdatawait(metamapping);
mapping_set_error(metamapping, error);
gfs2_ail_empty_gl(gl);
/*
* Writeback of the data mapping may cause the dirty flag to be set
* so we have to clear it again here.
*/
smp_mb__before_atomic();
clear_bit(GLF_DIRTY, &gl->gl_flags);
}
/**
* inode_go_inval - prepare a inode glock to be released
* @gl: the glock
* @flags:
*
* Normally we invalidate everything, but if we are moving into
* LM_ST_DEFERRED from LM_ST_SHARED or LM_ST_EXCLUSIVE then we
* can keep hold of the metadata, since it won't have changed.
*
*/
static void inode_go_inval(struct gfs2_glock *gl, int flags)
{
struct gfs2_inode *ip = gl->gl_object;
gfs2_assert_withdraw(gl->gl_sbd, !atomic_read(&gl->gl_ail_count));
if (flags & DIO_METADATA) {
struct address_space *mapping = gfs2_glock2aspace(gl);
truncate_inode_pages(mapping, 0);
if (ip) {
set_bit(GIF_INVALID, &ip->i_flags);
forget_all_cached_acls(&ip->i_inode);
gfs2_dir_hash_inval(ip);
}
}
if (ip == GFS2_I(gl->gl_sbd->sd_rindex)) {
gfs2_log_flush(gl->gl_sbd, NULL, NORMAL_FLUSH);
gl->gl_sbd->sd_rindex_uptodate = 0;
}
if (ip && S_ISREG(ip->i_inode.i_mode))
truncate_inode_pages(ip->i_inode.i_mapping, 0);
}
/**
* inode_go_demote_ok - Check to see if it's ok to unlock an inode glock
* @gl: the glock
*
* Returns: 1 if it's ok
*/
static int inode_go_demote_ok(const struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_holder *gh;
if (sdp->sd_jindex == gl->gl_object || sdp->sd_rindex == gl->gl_object)
return 0;
if (!list_empty(&gl->gl_holders)) {
gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
if (gh->gh_list.next != &gl->gl_holders)
return 0;
}
return 1;
}
/**
* gfs2_set_nlink - Set the inode's link count based on on-disk info
* @inode: The inode in question
* @nlink: The link count
*
* If the link count has hit zero, it must never be raised, whatever the
* on-disk inode might say. When new struct inodes are created the link
* count is set to 1, so that we can safely use this test even when reading
* in on disk information for the first time.
*/
static void gfs2_set_nlink(struct inode *inode, u32 nlink)
{
/*
* We will need to review setting the nlink count here in the
* light of the forthcoming ro bind mount work. This is a reminder
* to do that.
*/
if ((inode->i_nlink != nlink) && (inode->i_nlink != 0)) {
if (nlink == 0)
clear_nlink(inode);
else
set_nlink(inode, nlink);
}
}
static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
{
const struct gfs2_dinode *str = buf;
struct timespec atime;
u16 height, depth;
if (unlikely(ip->i_no_addr != be64_to_cpu(str->di_num.no_addr)))
goto corrupt;
ip->i_no_formal_ino = be64_to_cpu(str->di_num.no_formal_ino);
ip->i_inode.i_mode = be32_to_cpu(str->di_mode);
ip->i_inode.i_rdev = 0;
switch (ip->i_inode.i_mode & S_IFMT) {
case S_IFBLK:
case S_IFCHR:
ip->i_inode.i_rdev = MKDEV(be32_to_cpu(str->di_major),
be32_to_cpu(str->di_minor));
break;
};
i_uid_write(&ip->i_inode, be32_to_cpu(str->di_uid));
i_gid_write(&ip->i_inode, be32_to_cpu(str->di_gid));
gfs2_set_nlink(&ip->i_inode, be32_to_cpu(str->di_nlink));
i_size_write(&ip->i_inode, be64_to_cpu(str->di_size));
gfs2_set_inode_blocks(&ip->i_inode, be64_to_cpu(str->di_blocks));
atime.tv_sec = be64_to_cpu(str->di_atime);
atime.tv_nsec = be32_to_cpu(str->di_atime_nsec);
if (timespec_compare(&ip->i_inode.i_atime, &atime) < 0)
ip->i_inode.i_atime = atime;
ip->i_inode.i_mtime.tv_sec = be64_to_cpu(str->di_mtime);
ip->i_inode.i_mtime.tv_nsec = be32_to_cpu(str->di_mtime_nsec);
ip->i_inode.i_ctime.tv_sec = be64_to_cpu(str->di_ctime);
ip->i_inode.i_ctime.tv_nsec = be32_to_cpu(str->di_ctime_nsec);
ip->i_goal = be64_to_cpu(str->di_goal_meta);
ip->i_generation = be64_to_cpu(str->di_generation);
ip->i_diskflags = be32_to_cpu(str->di_flags);
ip->i_eattr = be64_to_cpu(str->di_eattr);
/* i_diskflags and i_eattr must be set before gfs2_set_inode_flags() */
gfs2_set_inode_flags(&ip->i_inode);
height = be16_to_cpu(str->di_height);
if (unlikely(height > GFS2_MAX_META_HEIGHT))
goto corrupt;
ip->i_height = (u8)height;
depth = be16_to_cpu(str->di_depth);
if (unlikely(depth > GFS2_DIR_MAX_DEPTH))
goto corrupt;
ip->i_depth = (u8)depth;
ip->i_entries = be32_to_cpu(str->di_entries);
if (S_ISREG(ip->i_inode.i_mode))
gfs2_set_aops(&ip->i_inode);
return 0;
corrupt:
gfs2_consist_inode(ip);
return -EIO;
}
/**
* gfs2_inode_refresh - Refresh the incore copy of the dinode
* @ip: The GFS2 inode
*
* Returns: errno
*/
int gfs2_inode_refresh(struct gfs2_inode *ip)
{
struct buffer_head *dibh;
int error;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
return error;
error = gfs2_dinode_in(ip, dibh->b_data);
brelse(dibh);
clear_bit(GIF_INVALID, &ip->i_flags);
return error;
}
/**
* inode_go_lock - operation done after an inode lock is locked by a process
* @gl: the glock
* @flags:
*
* Returns: errno
*/
static int inode_go_lock(struct gfs2_holder *gh)
{
struct gfs2_glock *gl = gh->gh_gl;
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_inode *ip = gl->gl_object;
int error = 0;
if (!ip || (gh->gh_flags & GL_SKIP))
return 0;
if (test_bit(GIF_INVALID, &ip->i_flags)) {
error = gfs2_inode_refresh(ip);
if (error)
return error;
}
if (gh->gh_state != LM_ST_DEFERRED)
inode_dio_wait(&ip->i_inode);
if ((ip->i_diskflags & GFS2_DIF_TRUNC_IN_PROG) &&
(gl->gl_state == LM_ST_EXCLUSIVE) &&
(gh->gh_state == LM_ST_EXCLUSIVE)) {
spin_lock(&sdp->sd_trunc_lock);
if (list_empty(&ip->i_trunc_list))
list_add(&sdp->sd_trunc_list, &ip->i_trunc_list);
spin_unlock(&sdp->sd_trunc_lock);
wake_up(&sdp->sd_quota_wait);
return 1;
}
return error;
}
/**
* inode_go_dump - print information about an inode
* @seq: The iterator
* @ip: the inode
*
*/
static void inode_go_dump(struct seq_file *seq, const struct gfs2_glock *gl)
{
const struct gfs2_inode *ip = gl->gl_object;
if (ip == NULL)
return;
gfs2_print_dbg(seq, " I: n:%llu/%llu t:%u f:0x%02lx d:0x%08x s:%llu\n",
(unsigned long long)ip->i_no_formal_ino,
(unsigned long long)ip->i_no_addr,
IF2DT(ip->i_inode.i_mode), ip->i_flags,
(unsigned int)ip->i_diskflags,
(unsigned long long)i_size_read(&ip->i_inode));
}
/**
* freeze_go_sync - promote/demote the freeze glock
* @gl: the glock
* @state: the requested state
* @flags:
*
*/
static void freeze_go_sync(struct gfs2_glock *gl)
{
int error = 0;
struct gfs2_sbd *sdp = gl->gl_sbd;
if (gl->gl_state == LM_ST_SHARED &&
test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
atomic_set(&sdp->sd_freeze_state, SFS_STARTING_FREEZE);
error = freeze_super(sdp->sd_vfs);
if (error) {
printk(KERN_INFO "GFS2: couldn't freeze filesystem: %d\n", error);
gfs2_assert_withdraw(sdp, 0);
}
queue_work(gfs2_freeze_wq, &sdp->sd_freeze_work);
gfs2_log_flush(sdp, NULL, FREEZE_FLUSH);
}
}
/**
* freeze_go_xmote_bh - After promoting/demoting the freeze glock
* @gl: the glock
*
*/
static int freeze_go_xmote_bh(struct gfs2_glock *gl, struct gfs2_holder *gh)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
struct gfs2_glock *j_gl = ip->i_gl;
struct gfs2_log_header_host head;
int error;
if (test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
error = gfs2_find_jhead(sdp->sd_jdesc, &head);
if (error)
gfs2_consist(sdp);
if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT))
gfs2_consist(sdp);
/* Initialize some head of the log stuff */
if (!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) {
sdp->sd_log_sequence = head.lh_sequence + 1;
gfs2_log_pointers_init(sdp, head.lh_blkno);
}
}
return 0;
}
/**
* trans_go_demote_ok
* @gl: the glock
*
* Always returns 0
*/
static int freeze_go_demote_ok(const struct gfs2_glock *gl)
{
return 0;
}
/**
* iopen_go_callback - schedule the dcache entry for the inode to be deleted
* @gl: the glock
*
* gl_spin lock is held while calling this
*/
static void iopen_go_callback(struct gfs2_glock *gl, bool remote)
{
struct gfs2_inode *ip = (struct gfs2_inode *)gl->gl_object;
struct gfs2_sbd *sdp = gl->gl_sbd;
if (!remote || (sdp->sd_vfs->s_flags & MS_RDONLY))
return;
if (gl->gl_demote_state == LM_ST_UNLOCKED &&
gl->gl_state == LM_ST_SHARED && ip) {
gl->gl_lockref.count++;
if (queue_work(gfs2_delete_workqueue, &gl->gl_delete) == 0)
gl->gl_lockref.count--;
}
}
const struct gfs2_glock_operations gfs2_meta_glops = {
.go_type = LM_TYPE_META,
};
const struct gfs2_glock_operations gfs2_inode_glops = {
.go_sync = inode_go_sync,
.go_inval = inode_go_inval,
.go_demote_ok = inode_go_demote_ok,
.go_lock = inode_go_lock,
.go_dump = inode_go_dump,
.go_type = LM_TYPE_INODE,
.go_flags = GLOF_ASPACE,
};
const struct gfs2_glock_operations gfs2_rgrp_glops = {
.go_sync = rgrp_go_sync,
.go_inval = rgrp_go_inval,
.go_lock = gfs2_rgrp_go_lock,
.go_unlock = gfs2_rgrp_go_unlock,
.go_dump = gfs2_rgrp_dump,
.go_type = LM_TYPE_RGRP,
.go_flags = GLOF_LVB,
};
const struct gfs2_glock_operations gfs2_freeze_glops = {
.go_sync = freeze_go_sync,
.go_xmote_bh = freeze_go_xmote_bh,
.go_demote_ok = freeze_go_demote_ok,
.go_type = LM_TYPE_NONDISK,
};
const struct gfs2_glock_operations gfs2_iopen_glops = {
.go_type = LM_TYPE_IOPEN,
.go_callback = iopen_go_callback,
};
const struct gfs2_glock_operations gfs2_flock_glops = {
.go_type = LM_TYPE_FLOCK,
};
const struct gfs2_glock_operations gfs2_nondisk_glops = {
.go_type = LM_TYPE_NONDISK,
};
const struct gfs2_glock_operations gfs2_quota_glops = {
.go_type = LM_TYPE_QUOTA,
.go_flags = GLOF_LVB,
};
const struct gfs2_glock_operations gfs2_journal_glops = {
.go_type = LM_TYPE_JOURNAL,
};
const struct gfs2_glock_operations *gfs2_glops_list[] = {
[LM_TYPE_META] = &gfs2_meta_glops,
[LM_TYPE_INODE] = &gfs2_inode_glops,
[LM_TYPE_RGRP] = &gfs2_rgrp_glops,
[LM_TYPE_IOPEN] = &gfs2_iopen_glops,
[LM_TYPE_FLOCK] = &gfs2_flock_glops,
[LM_TYPE_NONDISK] = &gfs2_nondisk_glops,
[LM_TYPE_QUOTA] = &gfs2_quota_glops,
[LM_TYPE_JOURNAL] = &gfs2_journal_glops,
};