1 files changed, 632 insertions, 0 deletions

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
new file mode 100644
index 000000000000..89a8b8fad2e7
--- /dev/null
+++ b/fs/gfs2/ops_address.c
@@ -0,0 +1,632 @@
+/*
+ * 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/pagemap.h>
+#include <linux/mpage.h>
+#include <linux/fs.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "bmap.h"
+#include "glock.h"
+#include "inode.h"
+#include "log.h"
+#include "meta_io.h"
+#include "ops_address.h"
+#include "page.h"
+#include "quota.h"
+#include "trans.h"
+#include "rgrp.h"
+#include "ops_file.h"
+
+/**
+ * gfs2_get_block - Fills in a buffer head with details about a block
+ * @inode: The inode
+ * @lblock: The block number to look up
+ * @bh_result: The buffer head to return the result in
+ * @create: Non-zero if we may add block to the file
+ *
+ * Returns: errno
+ */
+
+int gfs2_get_block(struct inode *inode, sector_t lblock,
+                   struct buffer_head *bh_result, int create)
+{
+        struct gfs2_inode *ip = get_v2ip(inode);
+        int new = create;
+        uint64_t dblock;
+        int error;
+
+        error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
+        if (error)
+                return error;
+
+        if (!dblock)
+                return 0;
+
+        map_bh(bh_result, inode->i_sb, dblock);
+        if (new)
+                set_buffer_new(bh_result);
+
+        return 0;
+}
+
+/**
+ * get_block_noalloc - Fills in a buffer head with details about a block
+ * @inode: The inode
+ * @lblock: The block number to look up
+ * @bh_result: The buffer head to return the result in
+ * @create: Non-zero if we may add block to the file
+ *
+ * Returns: errno
+ */
+
+static int get_block_noalloc(struct inode *inode, sector_t lblock,
+                             struct buffer_head *bh_result, int create)
+{
+        struct gfs2_inode *ip = get_v2ip(inode);
+        int new = 0;
+        uint64_t dblock;
+        int error;
+
+        error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
+        if (error)
+                return error;
+
+        if (dblock)
+                map_bh(bh_result, inode->i_sb, dblock);
+        else if (gfs2_assert_withdraw(ip->i_sbd, !create))
+                error = -EIO;
+
+        return error;
+}
+
+static int get_blocks(struct inode *inode, sector_t lblock,
+                      unsigned long max_blocks, struct buffer_head *bh_result,
+                      int create)
+{
+        struct gfs2_inode *ip = get_v2ip(inode);
+        int new = create;
+        uint64_t dblock;
+        uint32_t extlen;
+        int error;
+
+        error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
+        if (error)
+                return error;
+
+        if (!dblock)
+                return 0;
+
+        map_bh(bh_result, inode->i_sb, dblock);
+        if (new)
+                set_buffer_new(bh_result);
+
+        if (extlen > max_blocks)
+                extlen = max_blocks;
+        bh_result->b_size = extlen << inode->i_blkbits;
+
+        return 0;
+}
+
+static int get_blocks_noalloc(struct inode *inode, sector_t lblock,
+                              unsigned long max_blocks,
+                              struct buffer_head *bh_result, int create)
+{
+        struct gfs2_inode *ip = get_v2ip(inode);
+        int new = 0;
+        uint64_t dblock;
+        uint32_t extlen;
+        int error;
+
+        error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen);
+        if (error)
+                return error;
+
+        if (dblock) {
+                map_bh(bh_result, inode->i_sb, dblock);
+                if (extlen > max_blocks)
+                        extlen = max_blocks;
+                bh_result->b_size = extlen << inode->i_blkbits;
+        } else if (gfs2_assert_withdraw(ip->i_sbd, !create))
+                error = -EIO;
+
+        return error;
+}
+
+/**
+ * gfs2_writepage - Write complete page
+ * @page: Page to write
+ *
+ * Returns: errno
+ *
+ * Some of this is copied from block_write_full_page() although we still
+ * call it to do most of the work.
+ */
+
+static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
+{
+        struct inode *inode = page->mapping->host;
+        struct gfs2_inode *ip = get_v2ip(page->mapping->host);
+        struct gfs2_sbd *sdp = ip->i_sbd;
+        loff_t i_size = i_size_read(inode);
+        pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+        unsigned offset;
+        int error;
+        int done_trans = 0;
+
+        if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
+                unlock_page(page);
+                return -EIO;
+        }
+        if (get_transaction)
+                goto out_ignore;
+
+        /* Is the page fully outside i_size? (truncate in progress) */
+        offset = i_size & (PAGE_CACHE_SIZE-1);
+        if (page->index >= end_index+1 || !offset) {
+                page->mapping->a_ops->invalidatepage(page, 0);
+                unlock_page(page);
+                return 0; /* don't care */
+        }
+
+        if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
+                error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
+                if (error)
+                        goto out_ignore;
+                gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
+                done_trans = 1;
+        }
+        error = block_write_full_page(page, get_block_noalloc, wbc);
+        if (done_trans)
+                gfs2_trans_end(sdp);
+        gfs2_meta_cache_flush(ip);
+        return error;
+
+out_ignore:
+        redirty_page_for_writepage(wbc, page);
+        unlock_page(page);
+        return 0;
+}
+
+/**
+ * stuffed_readpage - Fill in a Linux page with stuffed file data
+ * @ip: the inode
+ * @page: the page
+ *
+ * Returns: errno
+ */
+
+static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
+{
+        struct buffer_head *dibh;
+        void *kaddr;
+        int error;
+
+        error = gfs2_meta_inode_buffer(ip, &dibh);
+        if (error)
+                return error;
+
+        kaddr = kmap_atomic(page, KM_USER0);
+        memcpy((char *)kaddr,
+               dibh->b_data + sizeof(struct gfs2_dinode),
+               ip->i_di.di_size);
+        memset((char *)kaddr + ip->i_di.di_size,
+               0,
+               PAGE_CACHE_SIZE - ip->i_di.di_size);
+        kunmap_atomic(page, KM_USER0);
+
+        brelse(dibh);
+
+        SetPageUptodate(page);
+
+        return 0;
+}
+
+static int zero_readpage(struct page *page)
+{
+        void *kaddr;
+
+        kaddr = kmap_atomic(page, KM_USER0);
+        memset(kaddr, 0, PAGE_CACHE_SIZE);
+        kunmap_atomic(page, KM_USER0);
+
+        SetPageUptodate(page);
+        unlock_page(page);
+
+        return 0;
+}
+
+/**
+ * gfs2_readpage - readpage with locking
+ * @file: The file to read a page for. N.B. This may be NULL if we are
+ * reading an internal file.
+ * @page: The page to read
+ *
+ * Returns: errno
+ */
+
+static int gfs2_readpage(struct file *file, struct page *page)
+{
+        struct gfs2_inode *ip = get_v2ip(page->mapping->host);
+        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_holder gh;
+        int error;
+
+        if (file != &gfs2_internal_file_sentinal) {
+                gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
+                error = gfs2_glock_nq_m_atime(1, &gh);
+                if (error)
+                        goto out_unlock;
+        }
+
+        if (gfs2_is_stuffed(ip)) {
+                if (!page->index) {
+                        error = stuffed_readpage(ip, page);
+                        unlock_page(page);
+                } else
+                        error = zero_readpage(page);
+        } else
+                error = mpage_readpage(page, gfs2_get_block);
+
+        if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+                error = -EIO;
+
+        if (file != &gfs2_internal_file_sentinal) {
+                gfs2_glock_dq_m(1, &gh);
+                gfs2_holder_uninit(&gh);
+        }
+out:
+        return error;
+out_unlock:
+        unlock_page(page);
+        goto out;
+}
+
+/**
+ * gfs2_prepare_write - Prepare to write a page to a file
+ * @file: The file to write to
+ * @page: The page which is to be prepared for writing
+ * @from: From (byte range within page)
+ * @to: To (byte range within page)
+ *
+ * Returns: errno
+ */
+
+static int gfs2_prepare_write(struct file *file, struct page *page,
+                              unsigned from, unsigned to)
+{
+        struct gfs2_inode *ip = get_v2ip(page->mapping->host);
+        struct gfs2_sbd *sdp = ip->i_sbd;
+        unsigned int data_blocks, ind_blocks, rblocks;
+        int alloc_required;
+        int error = 0;
+        loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
+        loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+        struct gfs2_alloc *al;
+
+        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh);
+        error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
+        if (error)
+                goto out_uninit;
+
+        gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks);
+
+        error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required);
+        if (error)
+                goto out_unlock;
+
+
+        if (alloc_required) {
+                al = gfs2_alloc_get(ip);
+
+                error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
+                if (error)
+                        goto out_alloc_put;
+
+                error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
+                if (error)
+                        goto out_qunlock;
+
+                al->al_requested = data_blocks + ind_blocks;
+                error = gfs2_inplace_reserve(ip);
+                if (error)
+                        goto out_qunlock;
+        }
+
+        rblocks = RES_DINODE + ind_blocks;
+        if (gfs2_is_jdata(ip))
+                rblocks += data_blocks ? data_blocks : 1;
+        if (ind_blocks || data_blocks)
+                rblocks += RES_STATFS + RES_QUOTA;
+
+        error = gfs2_trans_begin(sdp, rblocks, 0);
+        if (error)
+                goto out;
+
+        if (gfs2_is_stuffed(ip)) {
+                if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
+                        error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
+                                                    page);
+                        if (error == 0)
+                                goto prepare_write;
+                } else if (!PageUptodate(page))
+                        error = stuffed_readpage(ip, page);
+                goto out;
+        }
+
+prepare_write:
+        error = block_prepare_write(page, from, to, gfs2_get_block);
+
+out:
+        if (error) {
+                gfs2_trans_end(sdp);
+                if (alloc_required) {
+                        gfs2_inplace_release(ip);
+out_qunlock:
+                        gfs2_quota_unlock(ip);
+out_alloc_put:
+                        gfs2_alloc_put(ip);
+                }
+out_unlock:
+                gfs2_glock_dq_m(1, &ip->i_gh);
+out_uninit:
+                gfs2_holder_uninit(&ip->i_gh);
+        }
+
+        return error;
+}
+
+/**
+ * gfs2_commit_write - Commit write to a file
+ * @file: The file to write to
+ * @page: The page containing the data
+ * @from: From (byte range within page)
+ * @to: To (byte range within page)
+ *
+ * Returns: errno
+ */
+
+static int gfs2_commit_write(struct file *file, struct page *page,
+                             unsigned from, unsigned to)
+{
+        struct inode *inode = page->mapping->host;
+        struct gfs2_inode *ip = get_v2ip(inode);
+        struct gfs2_sbd *sdp = ip->i_sbd;
+        int error = -EOPNOTSUPP;
+        struct buffer_head *dibh;
+        struct gfs2_alloc *al = &ip->i_alloc;;
+
+        if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
+                goto fail_nounlock;
+
+        error = gfs2_meta_inode_buffer(ip, &dibh);
+        if (error)
+                goto fail_endtrans;
+
+        gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+
+        if (gfs2_is_stuffed(ip)) {
+                uint64_t file_size;
+                void *kaddr;
+
+                file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+                kaddr = kmap_atomic(page, KM_USER0);
+                memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
+                       (char *)kaddr + from, to - from);
+                kunmap_atomic(page, KM_USER0);
+
+                SetPageUptodate(page);
+
+                if (inode->i_size < file_size)
+                        i_size_write(inode, file_size);
+        } else {
+                if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED ||
+                    gfs2_is_jdata(ip))
+                        gfs2_page_add_databufs(ip, page, from, to);
+                error = generic_commit_write(file, page, from, to);
+                if (error)
+                        goto fail;
+        }
+
+        if (ip->i_di.di_size < inode->i_size)
+                ip->i_di.di_size = inode->i_size;
+
+        gfs2_dinode_out(&ip->i_di, dibh->b_data);
+        brelse(dibh);
+        gfs2_trans_end(sdp);
+        if (al->al_requested) {
+                gfs2_inplace_release(ip);
+                gfs2_quota_unlock(ip);
+                gfs2_alloc_put(ip);
+        }
+        gfs2_glock_dq_m(1, &ip->i_gh);
+        gfs2_holder_uninit(&ip->i_gh);
+        return 0;
+
+fail:
+        brelse(dibh);
+fail_endtrans:
+        gfs2_trans_end(sdp);
+        if (al->al_requested) {
+                gfs2_inplace_release(ip);
+                gfs2_quota_unlock(ip);
+                gfs2_alloc_put(ip);
+        }
+        gfs2_glock_dq_m(1, &ip->i_gh);
+        gfs2_holder_uninit(&ip->i_gh);
+fail_nounlock:
+        ClearPageUptodate(page);
+        return error;
+}
+
+/**
+ * gfs2_bmap - Block map function
+ * @mapping: Address space info
+ * @lblock: The block to map
+ *
+ * Returns: The disk address for the block or 0 on hole or error
+ */
+
+static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
+{
+        struct gfs2_inode *ip = get_v2ip(mapping->host);
+        struct gfs2_holder i_gh;
+        sector_t dblock = 0;
+        int error;
+
+        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
+        if (error)
+                return 0;
+
+        if (!gfs2_is_stuffed(ip))
+                dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);
+
+        gfs2_glock_dq_uninit(&i_gh);
+
+        return dblock;
+}
+
+static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+        struct gfs2_bufdata *bd;
+
+        gfs2_log_lock(sdp);
+        bd = get_v2bd(bh);
+        if (bd) {
+                bd->bd_bh = NULL;
+                set_v2bd(bh, NULL);
+                gfs2_log_unlock(sdp);
+                brelse(bh);
+        } else
+                gfs2_log_unlock(sdp);
+
+        lock_buffer(bh);
+        clear_buffer_dirty(bh);
+        bh->b_bdev = NULL;
+        clear_buffer_mapped(bh);
+        clear_buffer_req(bh);
+        clear_buffer_new(bh);
+        clear_buffer_delay(bh);
+        unlock_buffer(bh);
+}
+
+static int gfs2_invalidatepage(struct page *page, unsigned long offset)
+{
+        struct gfs2_sbd *sdp = get_v2sdp(page->mapping->host->i_sb);
+        struct buffer_head *head, *bh, *next;
+        unsigned int curr_off = 0;
+        int ret = 1;
+
+        BUG_ON(!PageLocked(page));
+        if (!page_has_buffers(page))
+                return 1;
+
+        bh = head = page_buffers(page);
+        do {
+                unsigned int next_off = curr_off + bh->b_size;
+                next = bh->b_this_page;
+
+                if (offset <= curr_off)
+                        discard_buffer(sdp, bh);
+
+                curr_off = next_off;
+                bh = next;
+        } while (bh != head);
+
+        if (!offset)
+                ret = try_to_release_page(page, 0);
+
+        return ret;
+}
+
+static ssize_t gfs2_direct_IO_write(struct kiocb *iocb, const struct iovec *iov,
+                                    loff_t offset, unsigned long nr_segs)
+{
+        struct file *file = iocb->ki_filp;
+        struct inode *inode = file->f_mapping->host;
+        struct gfs2_inode *ip = get_v2ip(inode);
+        struct gfs2_holder gh;
+        int rv;
+
+        /*
+         * Shared lock, even though its write, since we do no allocation
+         * on this path. All we need change is atime.
+         */
+        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
+        rv = gfs2_glock_nq_m_atime(1, &gh);
+        if (rv)
+                goto out;
+
+        /*
+         * Should we return an error here? I can't see that O_DIRECT for
+         * a journaled file makes any sense. For now we'll silently fall
+         * back to buffered I/O, likewise we do the same for stuffed
+         * files since they are (a) small and (b) unaligned.
+         */
+        if (gfs2_is_jdata(ip))
+                goto out;
+
+        if (gfs2_is_stuffed(ip))
+                goto out;
+
+        rv = __blockdev_direct_IO(WRITE, iocb, inode, inode->i_sb->s_bdev,
+                                  iov, offset, nr_segs, get_blocks_noalloc,
+                                  NULL, DIO_OWN_LOCKING);
+out:
+        gfs2_glock_dq_m(1, &gh);
+        gfs2_holder_uninit(&gh);
+
+        return rv;
+}
+
+/**
+ * gfs2_direct_IO
+ *
+ * This is called with a shared lock already held for the read path.
+ * Currently, no locks are held when the write path is called.
+ */
+static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
+                              const struct iovec *iov, loff_t offset,
+                              unsigned long nr_segs)
+{
+        struct file *file = iocb->ki_filp;
+        struct inode *inode = file->f_mapping->host;
+        struct gfs2_inode *ip = get_v2ip(inode);
+        struct gfs2_sbd *sdp = ip->i_sbd;
+
+        if (rw == WRITE)
+                return gfs2_direct_IO_write(iocb, iov, offset, nr_segs);
+
+        if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) ||
+            gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
+                return -EINVAL;
+
+        return __blockdev_direct_IO(READ, iocb, inode, inode->i_sb->s_bdev, iov,
+                                    offset, nr_segs, get_blocks, NULL,
+                                    DIO_OWN_LOCKING);
+}
+
+struct address_space_operations gfs2_file_aops = {
+        .writepage = gfs2_writepage,
+        .readpage = gfs2_readpage,
+        .sync_page = block_sync_page,
+        .prepare_write = gfs2_prepare_write,
+        .commit_write = gfs2_commit_write,
+        .bmap = gfs2_bmap,
+        .invalidatepage = gfs2_invalidatepage,
+        .direct_IO = gfs2_direct_IO,
+};
+