[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/nilfs2/mdt.c b/ap/os/linux/linux-3.4.x/fs/nilfs2/mdt.c
new file mode 100644
index 0000000..f9897d0
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nilfs2/mdt.c
@@ -0,0 +1,589 @@
+/*
+ * mdt.c - meta data file for NILFS
+ *
+ * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Written by Ryusuke Konishi <ryusuke@osrg.net>
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/mm.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include "nilfs.h"
+#include "btnode.h"
+#include "segment.h"
+#include "page.h"
+#include "mdt.h"
+
+
+#define NILFS_MDT_MAX_RA_BLOCKS (16 - 1)
+
+
+static int
+nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block,
+ struct buffer_head *bh,
+ void (*init_block)(struct inode *,
+ struct buffer_head *, void *))
+{
+ struct nilfs_inode_info *ii = NILFS_I(inode);
+ void *kaddr;
+ int ret;
+
+ /* Caller exclude read accesses using page lock */
+
+ /* set_buffer_new(bh); */
+ bh->b_blocknr = 0;
+
+ ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh);
+ if (unlikely(ret))
+ return ret;
+
+ set_buffer_mapped(bh);
+
+ kaddr = kmap_atomic(bh->b_page);
+ memset(kaddr + bh_offset(bh), 0, 1 << inode->i_blkbits);
+ if (init_block)
+ init_block(inode, bh, kaddr);
+ flush_dcache_page(bh->b_page);
+ kunmap_atomic(kaddr);
+
+ set_buffer_uptodate(bh);
+ mark_buffer_dirty(bh);
+ nilfs_mdt_mark_dirty(inode);
+ return 0;
+}
+
+static int nilfs_mdt_create_block(struct inode *inode, unsigned long block,
+ struct buffer_head **out_bh,
+ void (*init_block)(struct inode *,
+ struct buffer_head *,
+ void *))
+{
+ struct super_block *sb = inode->i_sb;
+ struct nilfs_transaction_info ti;
+ struct buffer_head *bh;
+ int err;
+
+ nilfs_transaction_begin(sb, &ti, 0);
+
+ err = -ENOMEM;
+ bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0);
+ if (unlikely(!bh))
+ goto failed_unlock;
+
+ err = -EEXIST;
+ if (buffer_uptodate(bh))
+ goto failed_bh;
+
+ wait_on_buffer(bh);
+ if (buffer_uptodate(bh))
+ goto failed_bh;
+
+ bh->b_bdev = sb->s_bdev;
+ err = nilfs_mdt_insert_new_block(inode, block, bh, init_block);
+ if (likely(!err)) {
+ get_bh(bh);
+ *out_bh = bh;
+ }
+
+ failed_bh:
+ unlock_page(bh->b_page);
+ page_cache_release(bh->b_page);
+ brelse(bh);
+
+ failed_unlock:
+ if (likely(!err))
+ err = nilfs_transaction_commit(sb);
+ else
+ nilfs_transaction_abort(sb);
+
+ return err;
+}
+
+static int
+nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff,
+ int mode, struct buffer_head **out_bh)
+{
+ struct buffer_head *bh;
+ __u64 blknum = 0;
+ int ret = -ENOMEM;
+
+ bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
+ if (unlikely(!bh))
+ goto failed;
+
+ ret = -EEXIST; /* internal code */
+ if (buffer_uptodate(bh))
+ goto out;
+
+ if (mode == READA) {
+ if (!trylock_buffer(bh)) {
+ ret = -EBUSY;
+ goto failed_bh;
+ }
+ } else /* mode == READ */
+ lock_buffer(bh);
+
+ if (buffer_uptodate(bh)) {
+ unlock_buffer(bh);
+ goto out;
+ }
+
+ ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum);
+ if (unlikely(ret)) {
+ unlock_buffer(bh);
+ goto failed_bh;
+ }
+ map_bh(bh, inode->i_sb, (sector_t)blknum);
+
+ bh->b_end_io = end_buffer_read_sync;
+ get_bh(bh);
+ submit_bh(mode, bh);
+ ret = 0;
+ out:
+ get_bh(bh);
+ *out_bh = bh;
+
+ failed_bh:
+ unlock_page(bh->b_page);
+ page_cache_release(bh->b_page);
+ brelse(bh);
+ failed:
+ return ret;
+}
+
+static int nilfs_mdt_read_block(struct inode *inode, unsigned long block,
+ int readahead, struct buffer_head **out_bh)
+{
+ struct buffer_head *first_bh, *bh;
+ unsigned long blkoff;
+ int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS;
+ int err;
+
+ err = nilfs_mdt_submit_block(inode, block, READ, &first_bh);
+ if (err == -EEXIST) /* internal code */
+ goto out;
+
+ if (unlikely(err))
+ goto failed;
+
+ if (readahead) {
+ blkoff = block + 1;
+ for (i = 0; i < nr_ra_blocks; i++, blkoff++) {
+ err = nilfs_mdt_submit_block(inode, blkoff, READA, &bh);
+ if (likely(!err || err == -EEXIST))
+ brelse(bh);
+ else if (err != -EBUSY)
+ break;
+ /* abort readahead if bmap lookup failed */
+ if (!buffer_locked(first_bh))
+ goto out_no_wait;
+ }
+ }
+
+ wait_on_buffer(first_bh);
+
+ out_no_wait:
+ err = -EIO;
+ if (!buffer_uptodate(first_bh))
+ goto failed_bh;
+ out:
+ *out_bh = first_bh;
+ return 0;
+
+ failed_bh:
+ brelse(first_bh);
+ failed:
+ return err;
+}
+
+/**
+ * nilfs_mdt_get_block - read or create a buffer on meta data file.
+ * @inode: inode of the meta data file
+ * @blkoff: block offset
+ * @create: create flag
+ * @init_block: initializer used for newly allocated block
+ * @out_bh: output of a pointer to the buffer_head
+ *
+ * nilfs_mdt_get_block() looks up the specified buffer and tries to create
+ * a new buffer if @create is not zero. On success, the returned buffer is
+ * assured to be either existing or formatted using a buffer lock on success.
+ * @out_bh is substituted only when zero is returned.
+ *
+ * Return Value: On success, it returns 0. On error, the following negative
+ * error code is returned.
+ *
+ * %-ENOMEM - Insufficient memory available.
+ *
+ * %-EIO - I/O error
+ *
+ * %-ENOENT - the specified block does not exist (hole block)
+ *
+ * %-EROFS - Read only filesystem (for create mode)
+ */
+int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create,
+ void (*init_block)(struct inode *,
+ struct buffer_head *, void *),
+ struct buffer_head **out_bh)
+{
+ int ret;
+
+ /* Should be rewritten with merging nilfs_mdt_read_block() */
+ retry:
+ ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh);
+ if (!create || ret != -ENOENT)
+ return ret;
+
+ ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block);
+ if (unlikely(ret == -EEXIST)) {
+ /* create = 0; */ /* limit read-create loop retries */
+ goto retry;
+ }
+ return ret;
+}
+
+/**
+ * nilfs_mdt_delete_block - make a hole on the meta data file.
+ * @inode: inode of the meta data file
+ * @block: block offset
+ *
+ * Return Value: On success, zero is returned.
+ * On error, one of the following negative error code is returned.
+ *
+ * %-ENOMEM - Insufficient memory available.
+ *
+ * %-EIO - I/O error
+ */
+int nilfs_mdt_delete_block(struct inode *inode, unsigned long block)
+{
+ struct nilfs_inode_info *ii = NILFS_I(inode);
+ int err;
+
+ err = nilfs_bmap_delete(ii->i_bmap, block);
+ if (!err || err == -ENOENT) {
+ nilfs_mdt_mark_dirty(inode);
+ nilfs_mdt_forget_block(inode, block);
+ }
+ return err;
+}
+
+/**
+ * nilfs_mdt_forget_block - discard dirty state and try to remove the page
+ * @inode: inode of the meta data file
+ * @block: block offset
+ *
+ * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and
+ * tries to release the page including the buffer from a page cache.
+ *
+ * Return Value: On success, 0 is returned. On error, one of the following
+ * negative error code is returned.
+ *
+ * %-EBUSY - page has an active buffer.
+ *
+ * %-ENOENT - page cache has no page addressed by the offset.
+ */
+int nilfs_mdt_forget_block(struct inode *inode, unsigned long block)
+{
+ pgoff_t index = (pgoff_t)block >>
+ (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ struct page *page;
+ unsigned long first_block;
+ int ret = 0;
+ int still_dirty;
+
+ page = find_lock_page(inode->i_mapping, index);
+ if (!page)
+ return -ENOENT;
+
+ wait_on_page_writeback(page);
+
+ first_block = (unsigned long)index <<
+ (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ if (page_has_buffers(page)) {
+ struct buffer_head *bh;
+
+ bh = nilfs_page_get_nth_block(page, block - first_block);
+ nilfs_forget_buffer(bh);
+ }
+ still_dirty = PageDirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+
+ if (still_dirty ||
+ invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0)
+ ret = -EBUSY;
+ return ret;
+}
+
+/**
+ * nilfs_mdt_mark_block_dirty - mark a block on the meta data file dirty.
+ * @inode: inode of the meta data file
+ * @block: block offset
+ *
+ * Return Value: On success, it returns 0. On error, the following negative
+ * error code is returned.
+ *
+ * %-ENOMEM - Insufficient memory available.
+ *
+ * %-EIO - I/O error
+ *
+ * %-ENOENT - the specified block does not exist (hole block)
+ */
+int nilfs_mdt_mark_block_dirty(struct inode *inode, unsigned long block)
+{
+ struct buffer_head *bh;
+ int err;
+
+ err = nilfs_mdt_read_block(inode, block, 0, &bh);
+ if (unlikely(err))
+ return err;
+ mark_buffer_dirty(bh);
+ nilfs_mdt_mark_dirty(inode);
+ brelse(bh);
+ return 0;
+}
+
+int nilfs_mdt_fetch_dirty(struct inode *inode)
+{
+ struct nilfs_inode_info *ii = NILFS_I(inode);
+
+ if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) {
+ set_bit(NILFS_I_DIRTY, &ii->i_state);
+ return 1;
+ }
+ return test_bit(NILFS_I_DIRTY, &ii->i_state);
+}
+
+static int
+nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
+{
+ struct inode *inode;
+ struct super_block *sb;
+ int err = 0;
+
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+
+ inode = page->mapping->host;
+ if (!inode)
+ return 0;
+
+ sb = inode->i_sb;
+
+ if (wbc->sync_mode == WB_SYNC_ALL)
+ err = nilfs_construct_segment(sb);
+ else if (wbc->for_reclaim)
+ nilfs_flush_segment(sb, inode->i_ino);
+
+ return err;
+}
+
+
+static const struct address_space_operations def_mdt_aops = {
+ .writepage = nilfs_mdt_write_page,
+};
+
+static const struct inode_operations def_mdt_iops;
+static const struct file_operations def_mdt_fops;
+
+
+int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
+{
+ struct nilfs_mdt_info *mi;
+
+ mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS);
+ if (!mi)
+ return -ENOMEM;
+
+ init_rwsem(&mi->mi_sem);
+ inode->i_private = mi;
+
+ inode->i_mode = S_IFREG;
+ mapping_set_gfp_mask(inode->i_mapping, gfp_mask);
+ inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
+
+ inode->i_op = &def_mdt_iops;
+ inode->i_fop = &def_mdt_fops;
+ inode->i_mapping->a_ops = &def_mdt_aops;
+
+ return 0;
+}
+
+void nilfs_mdt_set_entry_size(struct inode *inode, unsigned entry_size,
+ unsigned header_size)
+{
+ struct nilfs_mdt_info *mi = NILFS_MDT(inode);
+
+ mi->mi_entry_size = entry_size;
+ mi->mi_entries_per_block = (1 << inode->i_blkbits) / entry_size;
+ mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size);
+}
+
+/**
+ * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file
+ * @inode: inode of the metadata file
+ * @shadow: shadow mapping
+ */
+int nilfs_mdt_setup_shadow_map(struct inode *inode,
+ struct nilfs_shadow_map *shadow)
+{
+ struct nilfs_mdt_info *mi = NILFS_MDT(inode);
+ struct backing_dev_info *bdi = inode->i_sb->s_bdi;
+
+ INIT_LIST_HEAD(&shadow->frozen_buffers);
+ address_space_init_once(&shadow->frozen_data);
+ nilfs_mapping_init(&shadow->frozen_data, inode, bdi);
+ address_space_init_once(&shadow->frozen_btnodes);
+ nilfs_mapping_init(&shadow->frozen_btnodes, inode, bdi);
+ mi->mi_shadow = shadow;
+ return 0;
+}
+
+/**
+ * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map
+ * @inode: inode of the metadata file
+ */
+int nilfs_mdt_save_to_shadow_map(struct inode *inode)
+{
+ struct nilfs_mdt_info *mi = NILFS_MDT(inode);
+ struct nilfs_inode_info *ii = NILFS_I(inode);
+ struct nilfs_shadow_map *shadow = mi->mi_shadow;
+ int ret;
+
+ ret = nilfs_copy_dirty_pages(&shadow->frozen_data, inode->i_mapping);
+ if (ret)
+ goto out;
+
+ ret = nilfs_copy_dirty_pages(&shadow->frozen_btnodes,
+ &ii->i_btnode_cache);
+ if (ret)
+ goto out;
+
+ nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store);
+ out:
+ return ret;
+}
+
+int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh)
+{
+ struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
+ struct buffer_head *bh_frozen;
+ struct page *page;
+ int blkbits = inode->i_blkbits;
+
+ page = grab_cache_page(&shadow->frozen_data, bh->b_page->index);
+ if (!page)
+ return -ENOMEM;
+
+ if (!page_has_buffers(page))
+ create_empty_buffers(page, 1 << blkbits, 0);
+
+ bh_frozen = nilfs_page_get_nth_block(page, bh_offset(bh) >> blkbits);
+
+ if (!buffer_uptodate(bh_frozen))
+ nilfs_copy_buffer(bh_frozen, bh);
+ if (list_empty(&bh_frozen->b_assoc_buffers)) {
+ list_add_tail(&bh_frozen->b_assoc_buffers,
+ &shadow->frozen_buffers);
+ set_buffer_nilfs_redirected(bh);
+ } else {
+ brelse(bh_frozen); /* already frozen */
+ }
+
+ unlock_page(page);
+ page_cache_release(page);
+ return 0;
+}
+
+struct buffer_head *
+nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh)
+{
+ struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
+ struct buffer_head *bh_frozen = NULL;
+ struct page *page;
+ int n;
+
+ page = find_lock_page(&shadow->frozen_data, bh->b_page->index);
+ if (page) {
+ if (page_has_buffers(page)) {
+ n = bh_offset(bh) >> inode->i_blkbits;
+ bh_frozen = nilfs_page_get_nth_block(page, n);
+ }
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ return bh_frozen;
+}
+
+static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow)
+{
+ struct list_head *head = &shadow->frozen_buffers;
+ struct buffer_head *bh;
+
+ while (!list_empty(head)) {
+ bh = list_first_entry(head, struct buffer_head,
+ b_assoc_buffers);
+ list_del_init(&bh->b_assoc_buffers);
+ brelse(bh); /* drop ref-count to make it releasable */
+ }
+}
+
+/**
+ * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state
+ * @inode: inode of the metadata file
+ */
+void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
+{
+ struct nilfs_mdt_info *mi = NILFS_MDT(inode);
+ struct nilfs_inode_info *ii = NILFS_I(inode);
+ struct nilfs_shadow_map *shadow = mi->mi_shadow;
+
+ down_write(&mi->mi_sem);
+
+ if (mi->mi_palloc_cache)
+ nilfs_palloc_clear_cache(inode);
+
+ nilfs_clear_dirty_pages(inode->i_mapping);
+ nilfs_copy_back_pages(inode->i_mapping, &shadow->frozen_data);
+
+ nilfs_clear_dirty_pages(&ii->i_btnode_cache);
+ nilfs_copy_back_pages(&ii->i_btnode_cache, &shadow->frozen_btnodes);
+
+ nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store);
+
+ up_write(&mi->mi_sem);
+}
+
+/**
+ * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches
+ * @inode: inode of the metadata file
+ */
+void nilfs_mdt_clear_shadow_map(struct inode *inode)
+{
+ struct nilfs_mdt_info *mi = NILFS_MDT(inode);
+ struct nilfs_shadow_map *shadow = mi->mi_shadow;
+
+ down_write(&mi->mi_sem);
+ nilfs_release_frozen_buffers(shadow);
+ truncate_inode_pages(&shadow->frozen_data, 0);
+ truncate_inode_pages(&shadow->frozen_btnodes, 0);
+ up_write(&mi->mi_sem);
+}