1 files changed, 590 insertions, 0 deletions

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
new file mode 100644
index 000000000000..3912d6a4b1e6
--- /dev/null
+++ b/fs/gfs2/meta_io.c
@@ -0,0 +1,590 @@
+/*
+ * 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/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/swap.h>
+#include <linux/delay.h>
+#include <linux/bio.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/lm_interface.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "glock.h"
+#include "glops.h"
+#include "inode.h"
+#include "log.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "util.h"
+#include "ops_address.h"
+
+static int aspace_get_block(struct inode *inode, sector_t lblock,
+                            struct buffer_head *bh_result, int create)
+{
+        gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
+        return -EOPNOTSUPP;
+}
+
+static int gfs2_aspace_writepage(struct page *page,
+                                 struct writeback_control *wbc)
+{
+        return block_write_full_page(page, aspace_get_block, wbc);
+}
+
+static const struct address_space_operations aspace_aops = {
+        .writepage = gfs2_aspace_writepage,
+        .releasepage = gfs2_releasepage,
+};
+
+/**
+ * gfs2_aspace_get - Create and initialize a struct inode structure
+ * @sdp: the filesystem the aspace is in
+ *
+ * Right now a struct inode is just a struct inode.  Maybe Linux
+ * will supply a more lightweight address space construct (that works)
+ * in the future.
+ *
+ * Make sure pages/buffers in this aspace aren't in high memory.
+ *
+ * Returns: the aspace
+ */
+
+struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
+{
+        struct inode *aspace;
+
+        aspace = new_inode(sdp->sd_vfs);
+        if (aspace) {
+                mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
+                aspace->i_mapping->a_ops = &aspace_aops;
+                aspace->i_size = ~0ULL;
+                aspace->i_private = NULL;
+                insert_inode_hash(aspace);
+        }
+        return aspace;
+}
+
+void gfs2_aspace_put(struct inode *aspace)
+{
+        remove_inode_hash(aspace);
+        iput(aspace);
+}
+
+/**
+ * gfs2_meta_inval - Invalidate all buffers associated with a glock
+ * @gl: the glock
+ *
+ */
+
+void gfs2_meta_inval(struct gfs2_glock *gl)
+{
+        struct gfs2_sbd *sdp = gl->gl_sbd;
+        struct inode *aspace = gl->gl_aspace;
+        struct address_space *mapping = gl->gl_aspace->i_mapping;
+
+        gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
+
+        atomic_inc(&aspace->i_writecount);
+        truncate_inode_pages(mapping, 0);
+        atomic_dec(&aspace->i_writecount);
+
+        gfs2_assert_withdraw(sdp, !mapping->nrpages);
+}
+
+/**
+ * gfs2_meta_sync - Sync all buffers associated with a glock
+ * @gl: The glock
+ *
+ */
+
+void gfs2_meta_sync(struct gfs2_glock *gl)
+{
+        struct address_space *mapping = gl->gl_aspace->i_mapping;
+        int error;
+
+        filemap_fdatawrite(mapping);
+        error = filemap_fdatawait(mapping);
+
+        if (error)
+                gfs2_io_error(gl->gl_sbd);
+}
+
+/**
+ * getbuf - Get a buffer with a given address space
+ * @sdp: the filesystem
+ * @aspace: the address space
+ * @blkno: the block number (filesystem scope)
+ * @create: 1 if the buffer should be created
+ *
+ * Returns: the buffer
+ */
+
+static struct buffer_head *getbuf(struct gfs2_sbd *sdp, struct inode *aspace,
+                                  u64 blkno, int create)
+{
+        struct page *page;
+        struct buffer_head *bh;
+        unsigned int shift;
+        unsigned long index;
+        unsigned int bufnum;
+
+        shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
+        index = blkno >> shift;             /* convert block to page */
+        bufnum = blkno - (index << shift);  /* block buf index within page */
+
+        if (create) {
+                for (;;) {
+                        page = grab_cache_page(aspace->i_mapping, index);
+                        if (page)
+                                break;
+                        yield();
+                }
+        } else {
+                page = find_lock_page(aspace->i_mapping, index);
+                if (!page)
+                        return NULL;
+        }
+
+        if (!page_has_buffers(page))
+                create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
+
+        /* Locate header for our buffer within our page */
+        for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
+                /* Do nothing */;
+        get_bh(bh);
+
+        if (!buffer_mapped(bh))
+                map_bh(bh, sdp->sd_vfs, blkno);
+
+        unlock_page(page);
+        mark_page_accessed(page);
+        page_cache_release(page);
+
+        return bh;
+}
+
+static void meta_prep_new(struct buffer_head *bh)
+{
+        struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
+
+        lock_buffer(bh);
+        clear_buffer_dirty(bh);
+        set_buffer_uptodate(bh);
+        unlock_buffer(bh);
+
+        mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
+}
+
+/**
+ * gfs2_meta_new - Get a block
+ * @gl: The glock associated with this block
+ * @blkno: The block number
+ *
+ * Returns: The buffer
+ */
+
+struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
+{
+        struct buffer_head *bh;
+        bh = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
+        meta_prep_new(bh);
+        return bh;
+}
+
+/**
+ * gfs2_meta_read - Read a block from disk
+ * @gl: The glock covering the block
+ * @blkno: The block number
+ * @flags: flags
+ * @bhp: the place where the buffer is returned (NULL on failure)
+ *
+ * Returns: errno
+ */
+
+int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
+                   struct buffer_head **bhp)
+{
+        *bhp = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
+        if (!buffer_uptodate(*bhp))
+                ll_rw_block(READ_META, 1, bhp);
+        if (flags & DIO_WAIT) {
+                int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
+                if (error) {
+                        brelse(*bhp);
+                        return error;
+                }
+        }
+
+        return 0;
+}
+
+/**
+ * gfs2_meta_wait - Reread a block from disk
+ * @sdp: the filesystem
+ * @bh: The block to wait for
+ *
+ * Returns: errno
+ */
+
+int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+        if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+                return -EIO;
+
+        wait_on_buffer(bh);
+
+        if (!buffer_uptodate(bh)) {
+                struct gfs2_trans *tr = current->journal_info;
+                if (tr && tr->tr_touched)
+                        gfs2_io_error_bh(sdp, bh);
+                return -EIO;
+        }
+        if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+                return -EIO;
+
+        return 0;
+}
+
+/**
+ * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
+ * @gl: the glock the buffer belongs to
+ * @bh: The buffer to be attached to
+ * @meta: Flag to indicate whether its metadata or not
+ */
+
+void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
+                         int meta)
+{
+        struct gfs2_bufdata *bd;
+
+        if (meta)
+                lock_page(bh->b_page);
+
+        if (bh->b_private) {
+                if (meta)
+                        unlock_page(bh->b_page);
+                return;
+        }
+
+        bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
+        memset(bd, 0, sizeof(struct gfs2_bufdata));
+        bd->bd_bh = bh;
+        bd->bd_gl = gl;
+
+        INIT_LIST_HEAD(&bd->bd_list_tr);
+        if (meta)
+                lops_init_le(&bd->bd_le, &gfs2_buf_lops);
+        else
+                lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
+        bh->b_private = bd;
+
+        if (meta)
+                unlock_page(bh->b_page);
+}
+
+/**
+ * gfs2_pin - Pin a buffer in memory
+ * @sdp: the filesystem the buffer belongs to
+ * @bh: The buffer to be pinned
+ *
+ */
+
+void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+        struct gfs2_bufdata *bd = bh->b_private;
+
+        gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
+
+        if (test_set_buffer_pinned(bh))
+                gfs2_assert_withdraw(sdp, 0);
+
+        wait_on_buffer(bh);
+
+        /* If this buffer is in the AIL and it has already been written
+           to in-place disk block, remove it from the AIL. */
+
+        gfs2_log_lock(sdp);
+        if (bd->bd_ail && !buffer_in_io(bh))
+                list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
+        gfs2_log_unlock(sdp);
+
+        clear_buffer_dirty(bh);
+        wait_on_buffer(bh);
+
+        if (!buffer_uptodate(bh))
+                gfs2_io_error_bh(sdp, bh);
+
+        get_bh(bh);
+}
+
+/**
+ * gfs2_unpin - Unpin a buffer
+ * @sdp: the filesystem the buffer belongs to
+ * @bh: The buffer to unpin
+ * @ai:
+ *
+ */
+
+void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
+                struct gfs2_ail *ai)
+{
+        struct gfs2_bufdata *bd = bh->b_private;
+
+        gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
+
+        if (!buffer_pinned(bh))
+                gfs2_assert_withdraw(sdp, 0);
+
+        mark_buffer_dirty(bh);
+        clear_buffer_pinned(bh);
+
+        gfs2_log_lock(sdp);
+        if (bd->bd_ail) {
+                list_del(&bd->bd_ail_st_list);
+                brelse(bh);
+        } else {
+                struct gfs2_glock *gl = bd->bd_gl;
+                list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
+                atomic_inc(&gl->gl_ail_count);
+        }
+        bd->bd_ail = ai;
+        list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
+        gfs2_log_unlock(sdp);
+}
+
+/**
+ * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
+ * @ip: the inode who owns the buffers
+ * @bstart: the first buffer in the run
+ * @blen: the number of buffers in the run
+ *
+ */
+
+void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
+{
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+        struct inode *aspace = ip->i_gl->gl_aspace;
+        struct buffer_head *bh;
+
+        while (blen) {
+                bh = getbuf(sdp, aspace, bstart, NO_CREATE);
+                if (bh) {
+                        struct gfs2_bufdata *bd = bh->b_private;
+
+                        if (test_clear_buffer_pinned(bh)) {
+                                struct gfs2_trans *tr = current->journal_info;
+                                gfs2_log_lock(sdp);
+                                list_del_init(&bd->bd_le.le_list);
+                                gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
+                                sdp->sd_log_num_buf--;
+                                gfs2_log_unlock(sdp);
+                                tr->tr_num_buf_rm++;
+                                brelse(bh);
+                        }
+                        if (bd) {
+                                gfs2_log_lock(sdp);
+                                if (bd->bd_ail) {
+                                        u64 blkno = bh->b_blocknr;
+                                        bd->bd_ail = NULL;
+                                        list_del(&bd->bd_ail_st_list);
+                                        list_del(&bd->bd_ail_gl_list);
+                                        atomic_dec(&bd->bd_gl->gl_ail_count);
+                                        brelse(bh);
+                                        gfs2_log_unlock(sdp);
+                                        gfs2_trans_add_revoke(sdp, blkno);
+                                } else
+                                        gfs2_log_unlock(sdp);
+                        }
+
+                        lock_buffer(bh);
+                        clear_buffer_dirty(bh);
+                        clear_buffer_uptodate(bh);
+                        unlock_buffer(bh);
+
+                        brelse(bh);
+                }
+
+                bstart++;
+                blen--;
+        }
+}
+
+/**
+ * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
+ * @ip: The GFS2 inode
+ *
+ * This releases buffers that are in the most-recently-used array of
+ * blocks used for indirect block addressing for this inode.
+ */
+
+void gfs2_meta_cache_flush(struct gfs2_inode *ip)
+{
+        struct buffer_head **bh_slot;
+        unsigned int x;
+
+        spin_lock(&ip->i_spin);
+
+        for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
+                bh_slot = &ip->i_cache[x];
+                if (!*bh_slot)
+                        break;
+                brelse(*bh_slot);
+                *bh_slot = NULL;
+        }
+
+        spin_unlock(&ip->i_spin);
+}
+
+/**
+ * gfs2_meta_indirect_buffer - Get a metadata buffer
+ * @ip: The GFS2 inode
+ * @height: The level of this buf in the metadata (indir addr) tree (if any)
+ * @num: The block number (device relative) of the buffer
+ * @new: Non-zero if we may create a new buffer
+ * @bhp: the buffer is returned here
+ *
+ * Try to use the gfs2_inode's MRU metadata tree cache.
+ *
+ * Returns: errno
+ */
+
+int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
+                              int new, struct buffer_head **bhp)
+{
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+        struct gfs2_glock *gl = ip->i_gl;
+        struct buffer_head *bh = NULL, **bh_slot = ip->i_cache + height;
+        int in_cache = 0;
+
+        spin_lock(&ip->i_spin);
+        if (*bh_slot && (*bh_slot)->b_blocknr == num) {
+                bh = *bh_slot;
+                get_bh(bh);
+                in_cache = 1;
+        }
+        spin_unlock(&ip->i_spin);
+
+        if (!bh)
+                bh = getbuf(gl->gl_sbd, gl->gl_aspace, num, CREATE);
+
+        if (!bh)
+                return -ENOBUFS;
+
+        if (new) {
+                if (gfs2_assert_warn(sdp, height))
+                        goto err;
+                meta_prep_new(bh);
+                gfs2_trans_add_bh(ip->i_gl, bh, 1);
+                gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
+                gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
+        } else {
+                u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
+                if (!buffer_uptodate(bh)) {
+                        ll_rw_block(READ_META, 1, &bh);
+                        if (gfs2_meta_wait(sdp, bh))
+                                goto err;
+                }
+                if (gfs2_metatype_check(sdp, bh, mtype))
+                        goto err;
+        }
+
+        if (!in_cache) {
+                spin_lock(&ip->i_spin);
+                if (*bh_slot)
+                        brelse(*bh_slot);
+                *bh_slot = bh;
+                get_bh(bh);
+                spin_unlock(&ip->i_spin);
+        }
+
+        *bhp = bh;
+        return 0;
+err:
+        brelse(bh);
+        return -EIO;
+}
+
+/**
+ * gfs2_meta_ra - start readahead on an extent of a file
+ * @gl: the glock the blocks belong to
+ * @dblock: the starting disk block
+ * @extlen: the number of blocks in the extent
+ *
+ * returns: the first buffer in the extent
+ */
+
+struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
+{
+        struct gfs2_sbd *sdp = gl->gl_sbd;
+        struct inode *aspace = gl->gl_aspace;
+        struct buffer_head *first_bh, *bh;
+        u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
+                          sdp->sd_sb.sb_bsize_shift;
+
+        BUG_ON(!extlen);
+
+        if (max_ra < 1)
+                max_ra = 1;
+        if (extlen > max_ra)
+                extlen = max_ra;
+
+        first_bh = getbuf(sdp, aspace, dblock, CREATE);
+
+        if (buffer_uptodate(first_bh))
+                goto out;
+        if (!buffer_locked(first_bh))
+                ll_rw_block(READ_META, 1, &first_bh);
+
+        dblock++;
+        extlen--;
+
+        while (extlen) {
+                bh = getbuf(sdp, aspace, dblock, CREATE);
+
+                if (!buffer_uptodate(bh) && !buffer_locked(bh))
+                        ll_rw_block(READA, 1, &bh);
+                brelse(bh);
+                dblock++;
+                extlen--;
+                if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
+                        goto out;
+        }
+
+        wait_on_buffer(first_bh);
+out:
+        return first_bh;
+}
+
+/**
+ * gfs2_meta_syncfs - sync all the buffers in a filesystem
+ * @sdp: the filesystem
+ *
+ */
+
+void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
+{
+        gfs2_log_flush(sdp, NULL);
+        for (;;) {
+                gfs2_ail1_start(sdp, DIO_ALL);
+                if (gfs2_ail1_empty(sdp, DIO_ALL))
+                        break;
+                msleep(10);
+        }
+}
+