--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * Copyright (C) 2002, 2004 Oracle. All rights reserved.
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <asm/byteorder.h>
+
+#define MLOG_MASK_PREFIX ML_FILE_IO
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "aops.h"
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "file.h"
+#include "inode.h"
+#include "journal.h"
+#include "super.h"
+#include "symlink.h"
+
+#include "buffer_head_io.h"
+
+static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int err = -EIO;
+ int status;
+ struct ocfs2_dinode *fe = NULL;
+ struct buffer_head *bh = NULL;
+ struct buffer_head *buffer_cache_bh = NULL;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ void *kaddr;
+
+ mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
+ (unsigned long long)iblock, bh_result, create);
+
+ BUG_ON(ocfs2_inode_is_fast_symlink(inode));
+
+ if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
+ mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
+ (unsigned long long)iblock);
+ goto bail;
+ }
+
+ status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+ OCFS2_I(inode)->ip_blkno,
+ &bh, OCFS2_BH_CACHED, inode);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ fe = (struct ocfs2_dinode *) bh->b_data;
+
+ if (!OCFS2_IS_VALID_DINODE(fe)) {
+ mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
+ (unsigned long long)fe->i_blkno, 7, fe->i_signature);
+ goto bail;
+ }
+
+ if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
+ le32_to_cpu(fe->i_clusters))) {
+ mlog(ML_ERROR, "block offset is outside the allocated size: "
+ "%llu\n", (unsigned long long)iblock);
+ goto bail;
+ }
+
+ /* We don't use the page cache to create symlink data, so if
+ * need be, copy it over from the buffer cache. */
+ if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
+ u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
+ iblock;
+ buffer_cache_bh = sb_getblk(osb->sb, blkno);
+ if (!buffer_cache_bh) {
+ mlog(ML_ERROR, "couldn't getblock for symlink!\n");
+ goto bail;
+ }
+
+ /* we haven't locked out transactions, so a commit
+ * could've happened. Since we've got a reference on
+ * the bh, even if it commits while we're doing the
+ * copy, the data is still good. */
+ if (buffer_jbd(buffer_cache_bh)
+ && ocfs2_inode_is_new(inode)) {
+ kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
+ if (!kaddr) {
+ mlog(ML_ERROR, "couldn't kmap!\n");
+ goto bail;
+ }
+ memcpy(kaddr + (bh_result->b_size * iblock),
+ buffer_cache_bh->b_data,
+ bh_result->b_size);
+ kunmap_atomic(kaddr, KM_USER0);
+ set_buffer_uptodate(bh_result);
+ }
+ brelse(buffer_cache_bh);
+ }
+
+ map_bh(bh_result, inode->i_sb,
+ le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
+
+ err = 0;
+
+bail:
+ if (bh)
+ brelse(bh);
+
+ mlog_exit(err);
+ return err;
+}
+
+static int ocfs2_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int err = 0;
+ u64 p_blkno, past_eof;
+
+ mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
+ (unsigned long long)iblock, bh_result, create);
+
+ if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
+ mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
+ inode, inode->i_ino);
+
+ if (S_ISLNK(inode->i_mode)) {
+ /* this always does I/O for some reason. */
+ err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
+ goto bail;
+ }
+
+ /* this can happen if another node truncs after our extend! */
+ spin_lock(&OCFS2_I(inode)->ip_lock);
+ if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
+ OCFS2_I(inode)->ip_clusters))
+ err = -EIO;
+ spin_unlock(&OCFS2_I(inode)->ip_lock);
+ if (err)
+ goto bail;
+
+ err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
+ NULL);
+ if (err) {
+ mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
+ "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
+ (unsigned long long)p_blkno);
+ goto bail;
+ }
+
+ map_bh(bh_result, inode->i_sb, p_blkno);
+
+ if (bh_result->b_blocknr == 0) {
+ err = -EIO;
+ mlog(ML_ERROR, "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
+ (unsigned long long)iblock,
+ (unsigned long long)p_blkno,
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ }
+
+ past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
+ mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
+ (unsigned long long)past_eof);
+
+ if (create && (iblock >= past_eof))
+ set_buffer_new(bh_result);
+
+bail:
+ if (err < 0)
+ err = -EIO;
+
+ mlog_exit(err);
+ return err;
+}
+
+static int ocfs2_readpage(struct file *file, struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
+ int ret, unlock = 1;
+
+ mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
+
+ ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
+ if (ret != 0) {
+ if (ret == AOP_TRUNCATED_PAGE)
+ unlock = 0;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+ /*
+ * i_size might have just been updated as we grabed the meta lock. We
+ * might now be discovering a truncate that hit on another node.
+ * block_read_full_page->get_block freaks out if it is asked to read
+ * beyond the end of a file, so we check here. Callers
+ * (generic_file_read, fault->nopage) are clever enough to check i_size
+ * and notice that the page they just read isn't needed.
+ *
+ * XXX sys_readahead() seems to get that wrong?
+ */
+ if (start >= i_size_read(inode)) {
+ char *addr = kmap(page);
+ memset(addr, 0, PAGE_SIZE);
+ flush_dcache_page(page);
+ kunmap(page);
+ SetPageUptodate(page);
+ ret = 0;
+ goto out_alloc;
+ }
+
+ ret = ocfs2_data_lock_with_page(inode, 0, page);
+ if (ret != 0) {
+ if (ret == AOP_TRUNCATED_PAGE)
+ unlock = 0;
+ mlog_errno(ret);
+ goto out_alloc;
+ }
+
+ ret = block_read_full_page(page, ocfs2_get_block);
+ unlock = 0;
+
+ ocfs2_data_unlock(inode, 0);
+out_alloc:
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
+ ocfs2_meta_unlock(inode, 0);
+out:
+ if (unlock)
+ unlock_page(page);
+ mlog_exit(ret);
+ return ret;
+}
+
+/* Note: Because we don't support holes, our allocation has
+ * already happened (allocation writes zeros to the file data)
+ * so we don't have to worry about ordered writes in
+ * ocfs2_writepage.
+ *
+ * ->writepage is called during the process of invalidating the page cache
+ * during blocked lock processing. It can't block on any cluster locks
+ * to during block mapping. It's relying on the fact that the block
+ * mapping can't have disappeared under the dirty pages that it is
+ * being asked to write back.
+ */
+static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
+{
+ int ret;
+
+ mlog_entry("(0x%p)\n", page);
+
+ ret = block_write_full_page(page, ocfs2_get_block, wbc);
+
+ mlog_exit(ret);
+
+ return ret;
+}
+
+/* This can also be called from ocfs2_write_zero_page() which has done
+ * it's own cluster locking. */
+int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
+ unsigned from, unsigned to)
+{
+ int ret;
+
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+ ret = block_prepare_write(page, from, to, ocfs2_get_block);
+
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+ return ret;
+}
+
+/*
+ * ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called
+ * from loopback. It must be able to perform its own locking around
+ * ocfs2_get_block().
+ */
+static int ocfs2_prepare_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ struct inode *inode = page->mapping->host;
+ int ret;
+
+ mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
+
+ ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
+ if (ret != 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_prepare_write_nolock(inode, page, from, to);
+
+ ocfs2_meta_unlock(inode, 0);
+out:
+ mlog_exit(ret);
+ return ret;
+}
+
+/* Taken from ext3. We don't necessarily need the full blown
+ * functionality yet, but IMHO it's better to cut and paste the whole
+ * thing so we can avoid introducing our own bugs (and easily pick up
+ * their fixes when they happen) --Mark */
+static int walk_page_buffers( handle_t *handle,
+ struct buffer_head *head,
+ unsigned from,
+ unsigned to,
+ int *partial,
+ int (*fn)( handle_t *handle,
+ struct buffer_head *bh))
+{
+ struct buffer_head *bh;
+ unsigned block_start, block_end;
+ unsigned blocksize = head->b_size;
+ int err, ret = 0;
+ struct buffer_head *next;
+
+ for ( bh = head, block_start = 0;
+ ret == 0 && (bh != head || !block_start);
+ block_start = block_end, bh = next)
+ {
+ next = bh->b_this_page;
+ block_end = block_start + blocksize;
+ if (block_end <= from || block_start >= to) {
+ if (partial && !buffer_uptodate(bh))
+ *partial = 1;
+ continue;
+ }
+ err = (*fn)(handle, bh);
+ if (!ret)
+ ret = err;
+ }
+ return ret;
+}
+
+struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
+ struct page *page,
+ unsigned from,
+ unsigned to)
+{
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_journal_handle *handle = NULL;
+ int ret = 0;
+
+ handle = ocfs2_start_trans(osb, NULL, OCFS2_INODE_UPDATE_CREDITS);
+ if (!handle) {
+ ret = -ENOMEM;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ if (ocfs2_should_order_data(inode)) {
+ ret = walk_page_buffers(handle->k_handle,
+ page_buffers(page),
+ from, to, NULL,
+ ocfs2_journal_dirty_data);
+ if (ret < 0)
+ mlog_errno(ret);
+ }
+out:
+ if (ret) {
+ if (handle)
+ ocfs2_commit_trans(handle);
+ handle = ERR_PTR(ret);
+ }
+ return handle;
+}
+
+static int ocfs2_commit_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ int ret, extending = 0, locklevel = 0;
+ loff_t new_i_size;
+ struct buffer_head *di_bh = NULL;
+ struct inode *inode = page->mapping->host;
+ struct ocfs2_journal_handle *handle = NULL;
+
+ mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
+
+ /* NOTE: ocfs2_file_aio_write has ensured that it's safe for
+ * us to sample inode->i_size here without the metadata lock:
+ *
+ * 1) We're currently holding the inode alloc lock, so no
+ * nodes can change it underneath us.
+ *
+ * 2) We've had to take the metadata lock at least once
+ * already to check for extending writes, hence insuring
+ * that our current copy is also up to date.
+ */
+ new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+ if (new_i_size > i_size_read(inode)) {
+ extending = 1;
+ locklevel = 1;
+ }
+
+ ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, locklevel, page);
+ if (ret != 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_data_lock_with_page(inode, 1, page);
+ if (ret != 0) {
+ mlog_errno(ret);
+ goto out_unlock_meta;
+ }
+
+ if (extending) {
+ handle = ocfs2_start_walk_page_trans(inode, page, from, to);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ handle = NULL;
+ goto out_unlock_data;
+ }
+
+ /* Mark our buffer early. We'd rather catch this error up here
+ * as opposed to after a successful commit_write which would
+ * require us to set back inode->i_size. */
+ ret = ocfs2_journal_access(handle, inode, di_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+ }
+
+ /* might update i_size */
+ ret = generic_commit_write(file, page, from, to);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+
+ if (extending) {
+ loff_t size = (u64) i_size_read(inode);
+ struct ocfs2_dinode *di =
+ (struct ocfs2_dinode *)di_bh->b_data;
+
+ /* ocfs2_mark_inode_dirty is too heavy to use here. */
+ inode->i_blocks = ocfs2_align_bytes_to_sectors(size);
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+ di->i_size = cpu_to_le64(size);
+ di->i_ctime = di->i_mtime =
+ cpu_to_le64(inode->i_mtime.tv_sec);
+ di->i_ctime_nsec = di->i_mtime_nsec =
+ cpu_to_le32(inode->i_mtime.tv_nsec);
+
+ ret = ocfs2_journal_dirty(handle, di_bh);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+ }
+
+ BUG_ON(extending && (i_size_read(inode) != new_i_size));
+
+out_commit:
+ if (handle)
+ ocfs2_commit_trans(handle);
+out_unlock_data:
+ ocfs2_data_unlock(inode, 1);
+out_unlock_meta:
+ ocfs2_meta_unlock(inode, locklevel);
+out:
+ if (di_bh)
+ brelse(di_bh);
+
+ mlog_exit(ret);
+ return ret;
+}
+
+static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
+{
+ sector_t status;
+ u64 p_blkno = 0;
+ int err = 0;
+ struct inode *inode = mapping->host;
+
+ mlog_entry("(block = %llu)\n", (unsigned long long)block);
+
+ /* We don't need to lock journal system files, since they aren't
+ * accessed concurrently from multiple nodes.
+ */
+ if (!INODE_JOURNAL(inode)) {
+ err = ocfs2_meta_lock(inode, NULL, NULL, 0);
+ if (err) {
+ if (err != -ENOENT)
+ mlog_errno(err);
+ goto bail;
+ }
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
+ }
+
+ err = ocfs2_extent_map_get_blocks(inode, block, 1, &p_blkno,
+ NULL);
+
+ if (!INODE_JOURNAL(inode)) {
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
+ ocfs2_meta_unlock(inode, 0);
+ }
+
+ if (err) {
+ mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
+ (unsigned long long)block);
+ mlog_errno(err);
+ goto bail;
+ }
+
+
+bail:
+ status = err ? 0 : p_blkno;
+
+ mlog_exit((int)status);
+
+ return status;
+}
+
+/*
+ * TODO: Make this into a generic get_blocks function.
+ *
+ * From do_direct_io in direct-io.c:
+ * "So what we do is to permit the ->get_blocks function to populate
+ * bh.b_size with the size of IO which is permitted at this offset and
+ * this i_blkbits."
+ *
+ * This function is called directly from get_more_blocks in direct-io.c.
+ *
+ * called like this: dio->get_blocks(dio->inode, fs_startblk,
+ * fs_count, map_bh, dio->rw == WRITE);
+ */
+static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ int ret;
+ u64 vbo_max; /* file offset, max_blocks from iblock */
+ u64 p_blkno;
+ int contig_blocks;
+ unsigned char blocksize_bits;
+ unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
+
+ if (!inode || !bh_result) {
+ mlog(ML_ERROR, "inode or bh_result is null\n");
+ return -EIO;
+ }
+
+ blocksize_bits = inode->i_sb->s_blocksize_bits;
+
+ /* This function won't even be called if the request isn't all
+ * nicely aligned and of the right size, so there's no need
+ * for us to check any of that. */
+
+ vbo_max = ((u64)iblock + max_blocks) << blocksize_bits;
+
+ spin_lock(&OCFS2_I(inode)->ip_lock);
+ if ((iblock + max_blocks) >
+ ocfs2_clusters_to_blocks(inode->i_sb,
+ OCFS2_I(inode)->ip_clusters)) {
+ spin_unlock(&OCFS2_I(inode)->ip_lock);
+ ret = -EIO;
+ goto bail;
+ }
+ spin_unlock(&OCFS2_I(inode)->ip_lock);
+
+ /* This figures out the size of the next contiguous block, and
+ * our logical offset */
+ ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
+ &contig_blocks);
+ if (ret) {
+ mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
+ (unsigned long long)iblock);
+ ret = -EIO;
+ goto bail;
+ }
+
+ map_bh(bh_result, inode->i_sb, p_blkno);
+
+ /* make sure we don't map more than max_blocks blocks here as
+ that's all the kernel will handle at this point. */
+ if (max_blocks < contig_blocks)
+ contig_blocks = max_blocks;
+ bh_result->b_size = contig_blocks << blocksize_bits;
+bail:
+ return ret;
+}
+
+/*
+ * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
+ * particularly interested in the aio/dio case. Like the core uses
+ * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
+ * truncation on another.
+ */
+static void ocfs2_dio_end_io(struct kiocb *iocb,
+ loff_t offset,
+ ssize_t bytes,
+ void *private)
+{
+ struct inode *inode = iocb->ki_filp->f_dentry->d_inode;
+
+ /* this io's submitter should not have unlocked this before we could */
+ BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
+ ocfs2_iocb_clear_rw_locked(iocb);
+ up_read(&inode->i_alloc_sem);
+ ocfs2_rw_unlock(inode, 0);
+}
+
+static ssize_t ocfs2_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_dentry->d_inode->i_mapping->host;
+ int ret;
+
+ mlog_entry_void();
+
+ /*
+ * We get PR data locks even for O_DIRECT. This allows
+ * concurrent O_DIRECT I/O but doesn't let O_DIRECT with
+ * extending and buffered zeroing writes race. If they did
+ * race then the buffered zeroing could be written back after
+ * the O_DIRECT I/O. It's one thing to tell people not to mix
+ * buffered and O_DIRECT writes, but expecting them to
+ * understand that file extension is also an implicit buffered
+ * write is too much. By getting the PR we force writeback of
+ * the buffered zeroing before proceeding.
+ */
+ ret = ocfs2_data_lock(inode, 0);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ ocfs2_data_unlock(inode, 0);
+
+ ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
+ inode->i_sb->s_bdev, iov, offset,
+ nr_segs,
+ ocfs2_direct_IO_get_blocks,
+ ocfs2_dio_end_io);
+out:
+ mlog_exit(ret);
+ return ret;
+}
+
+struct address_space_operations ocfs2_aops = {
+ .readpage = ocfs2_readpage,
+ .writepage = ocfs2_writepage,
+ .prepare_write = ocfs2_prepare_write,
+ .commit_write = ocfs2_commit_write,
+ .bmap = ocfs2_bmap,
+ .sync_page = block_sync_page,
+ .direct_IO = ocfs2_direct_IO
+};
git://git.onelab.eu / linux-2.6.git / blobdiff