1 files changed, 453 insertions, 0 deletions

diff --git a/fs/gfs2/unlinked.c b/fs/gfs2/unlinked.c
new file mode 100644
index 0000000..4a993af
--- /dev/null
+++ b/fs/gfs2/unlinked.c
@@ -0,0 +1,453 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 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 v.2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/kthread.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "bmap.h"
+#include "inode.h"
+#include "meta_io.h"
+#include "trans.h"
+#include "unlinked.h"
+
+static int munge_ondisk(struct gfs2_sbd *sdp, unsigned int slot,
+			struct gfs2_unlinked_tag *ut)
+{
+	struct gfs2_inode *ip = sdp->sd_ut_inode;
+	unsigned int block, offset;
+	uint64_t dblock;
+	int new = 0;
+	struct buffer_head *bh;
+	int error;
+
+	block = slot / sdp->sd_ut_per_block;
+	offset = slot % sdp->sd_ut_per_block;
+
+	error = gfs2_block_map(ip, block, &new, &dblock, NULL);
+	if (error)
+		return error;
+	error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT, &bh);
+	if (error)
+		return error;
+	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) {
+		error = -EIO;
+		goto out;
+	}
+
+	down(&sdp->sd_unlinked_mutex);
+	gfs2_trans_add_bh(ip->i_gl, bh);
+	gfs2_unlinked_tag_out(ut, bh->b_data +
+				  sizeof(struct gfs2_meta_header) +
+				  offset * sizeof(struct gfs2_unlinked_tag));
+	up(&sdp->sd_unlinked_mutex);
+
+ out:
+	brelse(bh);
+
+	return error;
+}
+
+static void ul_hash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
+{
+	spin_lock(&sdp->sd_unlinked_spin);
+	list_add(&ul->ul_list, &sdp->sd_unlinked_list);
+	gfs2_assert(sdp, ul->ul_count);
+	ul->ul_count++;
+	atomic_inc(&sdp->sd_unlinked_count);
+	spin_unlock(&sdp->sd_unlinked_spin);
+}
+
+static void ul_unhash(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
+{
+	spin_lock(&sdp->sd_unlinked_spin);
+	list_del_init(&ul->ul_list);
+	gfs2_assert(sdp, ul->ul_count > 1);
+	ul->ul_count--;
+	gfs2_assert_warn(sdp, atomic_read(&sdp->sd_unlinked_count) > 0);
+	atomic_dec(&sdp->sd_unlinked_count);
+	spin_unlock(&sdp->sd_unlinked_spin);
+}
+
+static struct gfs2_unlinked *ul_fish(struct gfs2_sbd *sdp)
+{
+	struct list_head *head;
+	struct gfs2_unlinked *ul;
+	int found = 0;
+
+	if (sdp->sd_vfs->s_flags & MS_RDONLY)
+		return NULL;
+
+	spin_lock(&sdp->sd_unlinked_spin);
+
+	head = &sdp->sd_unlinked_list;
+
+	list_for_each_entry(ul, head, ul_list) {
+		if (test_bit(ULF_LOCKED, &ul->ul_flags))
+			continue;
+
+		list_move_tail(&ul->ul_list, head);
+		ul->ul_count++;
+		set_bit(ULF_LOCKED, &ul->ul_flags);
+		found = 1;
+
+		break;
+	}
+
+	if (!found)
+		ul = NULL;
+
+	spin_unlock(&sdp->sd_unlinked_spin);
+
+	return ul;
+}
+
+/**
+ * enforce_limit - limit the number of inodes waiting to be deallocated
+ * @sdp: the filesystem
+ *
+ * Returns: errno
+ */
+
+static void enforce_limit(struct gfs2_sbd *sdp)
+{
+	unsigned int tries = 0, min = 0;
+	int error;
+
+	if (atomic_read(&sdp->sd_unlinked_count) >=
+	    gfs2_tune_get(sdp, gt_ilimit)) {
+		tries = gfs2_tune_get(sdp, gt_ilimit_tries);
+		min = gfs2_tune_get(sdp, gt_ilimit_min);
+	}
+
+	while (tries--) {
+		struct gfs2_unlinked *ul = ul_fish(sdp);
+		if (!ul)
+			break;
+		error = gfs2_inode_dealloc(sdp, ul);
+		gfs2_unlinked_put(sdp, ul);
+
+		if (!error) {
+			if (!--min)
+				break;
+		} else if (error != 1)
+			break;
+	}
+}
+
+static struct gfs2_unlinked *ul_alloc(struct gfs2_sbd *sdp)
+{
+	struct gfs2_unlinked *ul;
+
+	ul = kzalloc(sizeof(struct gfs2_unlinked), GFP_KERNEL);
+	if (ul) {
+		INIT_LIST_HEAD(&ul->ul_list);
+		ul->ul_count = 1;
+		set_bit(ULF_LOCKED, &ul->ul_flags);
+	}
+
+	return ul;
+}
+
+int gfs2_unlinked_get(struct gfs2_sbd *sdp, struct gfs2_unlinked **ul)
+{
+	unsigned int c, o = 0, b;
+	unsigned char byte = 0;
+
+	enforce_limit(sdp);
+
+	*ul = ul_alloc(sdp);
+	if (!*ul)
+		return -ENOMEM;
+
+	spin_lock(&sdp->sd_unlinked_spin);
+
+	for (c = 0; c < sdp->sd_unlinked_chunks; c++)
+		for (o = 0; o < PAGE_SIZE; o++) {
+			byte = sdp->sd_unlinked_bitmap[c][o];
+			if (byte != 0xFF)
+				goto found;
+		}
+
+	goto fail;
+
+ found:
+	for (b = 0; b < 8; b++)
+		if (!(byte & (1 << b)))
+			break;
+	(*ul)->ul_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
+
+	if ((*ul)->ul_slot >= sdp->sd_unlinked_slots)
+		goto fail;
+
+	sdp->sd_unlinked_bitmap[c][o] |= 1 << b;
+
+	spin_unlock(&sdp->sd_unlinked_spin);
+
+	return 0;
+
+ fail:
+	spin_unlock(&sdp->sd_unlinked_spin);
+	kfree(*ul);
+	return -ENOSPC;
+}
+
+void gfs2_unlinked_put(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
+{
+	gfs2_assert_warn(sdp, test_and_clear_bit(ULF_LOCKED, &ul->ul_flags));
+
+	spin_lock(&sdp->sd_unlinked_spin);
+	gfs2_assert(sdp, ul->ul_count);
+	ul->ul_count--;
+	if (!ul->ul_count) {
+		gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, ul->ul_slot, 0);
+		spin_unlock(&sdp->sd_unlinked_spin);
+		kfree(ul);
+	} else
+		spin_unlock(&sdp->sd_unlinked_spin);
+}
+
+int gfs2_unlinked_ondisk_add(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
+{
+	int error;
+
+	gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
+	gfs2_assert_warn(sdp, list_empty(&ul->ul_list));
+
+	error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut);
+	if (!error)
+		ul_hash(sdp, ul);
+
+	return error;
+}
+
+int gfs2_unlinked_ondisk_munge(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
+{
+	int error;
+
+	gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
+	gfs2_assert_warn(sdp, !list_empty(&ul->ul_list));
+
+	error = munge_ondisk(sdp, ul->ul_slot, &ul->ul_ut);
+
+	return error;
+}
+
+int gfs2_unlinked_ondisk_rm(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
+{
+	struct gfs2_unlinked_tag ut;
+	int error;
+
+	gfs2_assert_warn(sdp, test_bit(ULF_LOCKED, &ul->ul_flags));
+	gfs2_assert_warn(sdp, !list_empty(&ul->ul_list));
+
+	memset(&ut, 0, sizeof(struct gfs2_unlinked_tag));
+
+	error = munge_ondisk(sdp, ul->ul_slot, &ut);
+	if (error)
+		return error;
+
+	ul_unhash(sdp, ul);
+
+	return 0;
+}
+
+/**
+ * gfs2_unlinked_dealloc - Go through the list of inodes to be deallocated
+ * @sdp: the filesystem
+ *
+ * Returns: errno
+ */
+
+int gfs2_unlinked_dealloc(struct gfs2_sbd *sdp)
+{
+	unsigned int hits, strikes;
+	int error;
+
+	for (;;) {
+		hits = 0;
+		strikes = 0;
+
+		for (;;) {
+			struct gfs2_unlinked *ul = ul_fish(sdp);
+			if (!ul)
+				return 0;
+			error = gfs2_inode_dealloc(sdp, ul);
+			gfs2_unlinked_put(sdp, ul);
+
+			if (!error) {
+				hits++;
+				if (strikes)
+					strikes--;
+			} else if (error == 1) {
+				strikes++;
+				if (strikes >=
+				    atomic_read(&sdp->sd_unlinked_count)) {
+					error = 0;
+					break;
+				}
+			} else
+				return error;
+		}
+
+		if (!hits || kthread_should_stop())
+			break;
+
+		cond_resched();
+	}
+
+	return 0;
+}
+
+int gfs2_unlinked_init(struct gfs2_sbd *sdp)
+{
+	struct gfs2_inode *ip = sdp->sd_ut_inode;
+	unsigned int blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
+	unsigned int x, slot = 0;
+	unsigned int found = 0;
+	uint64_t dblock;
+	uint32_t extlen = 0;
+	int error;
+
+	if (!ip->i_di.di_size ||
+	    ip->i_di.di_size > (64 << 20) ||
+	    ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1)) {
+		gfs2_consist_inode(ip);
+		return -EIO;		
+	}
+	sdp->sd_unlinked_slots = blocks * sdp->sd_ut_per_block;
+	sdp->sd_unlinked_chunks = DIV_RU(sdp->sd_unlinked_slots, 8 * PAGE_SIZE);
+
+	error = -ENOMEM;
+
+	sdp->sd_unlinked_bitmap = kcalloc(sdp->sd_unlinked_chunks,
+					  sizeof(unsigned char *),
+					  GFP_KERNEL);
+	if (!sdp->sd_unlinked_bitmap)
+		return error;
+
+	for (x = 0; x < sdp->sd_unlinked_chunks; x++) {
+		sdp->sd_unlinked_bitmap[x] = kzalloc(PAGE_SIZE, GFP_KERNEL);
+		if (!sdp->sd_unlinked_bitmap[x])
+			goto fail;
+	}
+
+	for (x = 0; x < blocks; x++) {
+		struct buffer_head *bh;
+		unsigned int y;
+
+		if (!extlen) {
+			int new = 0;
+			error = gfs2_block_map(ip, x, &new, &dblock, &extlen);
+			if (error)
+				goto fail;
+		}
+		gfs2_meta_ra(ip->i_gl, dblock, extlen);
+		error = gfs2_meta_read(ip->i_gl, dblock, DIO_START | DIO_WAIT,
+				       &bh);
+		if (error)
+			goto fail;
+		error = -EIO;
+		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_UT)) {
+			brelse(bh);
+			goto fail;
+		}
+
+		for (y = 0;
+		     y < sdp->sd_ut_per_block && slot < sdp->sd_unlinked_slots;
+		     y++, slot++) {
+			struct gfs2_unlinked_tag ut;
+			struct gfs2_unlinked *ul;
+
+			gfs2_unlinked_tag_in(&ut, bh->b_data +
+					  sizeof(struct gfs2_meta_header) +
+					  y * sizeof(struct gfs2_unlinked_tag));
+			if (!ut.ut_inum.no_addr)
+				continue;
+
+			error = -ENOMEM;
+			ul = ul_alloc(sdp);
+			if (!ul) {
+				brelse(bh);
+				goto fail;
+			}
+			ul->ul_ut = ut;
+			ul->ul_slot = slot;
+
+			spin_lock(&sdp->sd_unlinked_spin);
+			gfs2_icbit_munge(sdp, sdp->sd_unlinked_bitmap, slot, 1);
+			spin_unlock(&sdp->sd_unlinked_spin);
+			ul_hash(sdp, ul);
+
+			gfs2_unlinked_put(sdp, ul);
+			found++;
+		}
+
+		brelse(bh);
+		dblock++;
+		extlen--;
+	}
+
+	if (found)
+		fs_info(sdp, "found %u unlinked inodes\n", found);
+
+	return 0;
+
+ fail:
+	gfs2_unlinked_cleanup(sdp);
+	return error;
+}
+
+/**
+ * gfs2_unlinked_cleanup - get rid of any extra struct gfs2_unlinked structures
+ * @sdp: the filesystem
+ *
+ */
+
+void gfs2_unlinked_cleanup(struct gfs2_sbd *sdp)
+{
+	struct list_head *head = &sdp->sd_unlinked_list;
+	struct gfs2_unlinked *ul;
+	unsigned int x;
+
+	spin_lock(&sdp->sd_unlinked_spin);
+	while (!list_empty(head)) {
+		ul = list_entry(head->next, struct gfs2_unlinked, ul_list);
+
+		if (ul->ul_count > 1) {
+			list_move_tail(&ul->ul_list, head);
+			spin_unlock(&sdp->sd_unlinked_spin);
+			schedule();
+			spin_lock(&sdp->sd_unlinked_spin);
+			continue;
+		}
+
+		list_del_init(&ul->ul_list);
+		atomic_dec(&sdp->sd_unlinked_count);
+
+		gfs2_assert_warn(sdp, ul->ul_count == 1);
+		gfs2_assert_warn(sdp, !test_bit(ULF_LOCKED, &ul->ul_flags));
+		kfree(ul);
+	}
+	spin_unlock(&sdp->sd_unlinked_spin);
+
+	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_unlinked_count));
+
+	if (sdp->sd_unlinked_bitmap) {
+		for (x = 0; x < sdp->sd_unlinked_chunks; x++)
+			kfree(sdp->sd_unlinked_bitmap[x]);
+		kfree(sdp->sd_unlinked_bitmap);
+	}
+}
+