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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/ocfs2/mmap.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/ocfs2/mmap.c')
-rw-r--r--fs/ocfs2/mmap.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
new file mode 100644
index 000000000..1834f2652
--- /dev/null
+++ b/fs/ocfs2/mmap.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * mmap.c
+ *
+ * Code to deal with the mess that is clustered mmap.
+ *
+ * Copyright (C) 2002, 2004 Oracle. All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/uio.h>
+#include <linux/signal.h>
+#include <linux/rbtree.h>
+
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "aops.h"
+#include "dlmglue.h"
+#include "file.h"
+#include "inode.h"
+#include "mmap.h"
+#include "super.h"
+#include "ocfs2_trace.h"
+
+
+static vm_fault_t ocfs2_fault(struct vm_fault *vmf)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ sigset_t oldset;
+ vm_fault_t ret;
+
+ ocfs2_block_signals(&oldset);
+ ret = filemap_fault(vmf);
+ ocfs2_unblock_signals(&oldset);
+
+ trace_ocfs2_fault(OCFS2_I(vma->vm_file->f_mapping->host)->ip_blkno,
+ vma, vmf->page, vmf->pgoff);
+ return ret;
+}
+
+static vm_fault_t __ocfs2_page_mkwrite(struct file *file,
+ struct buffer_head *di_bh, struct page *page)
+{
+ int err;
+ vm_fault_t ret = VM_FAULT_NOPAGE;
+ struct inode *inode = file_inode(file);
+ struct address_space *mapping = inode->i_mapping;
+ loff_t pos = page_offset(page);
+ unsigned int len = PAGE_SIZE;
+ pgoff_t last_index;
+ struct page *locked_page = NULL;
+ void *fsdata;
+ loff_t size = i_size_read(inode);
+
+ last_index = (size - 1) >> PAGE_SHIFT;
+
+ /*
+ * There are cases that lead to the page no longer belonging to the
+ * mapping.
+ * 1) pagecache truncates locally due to memory pressure.
+ * 2) pagecache truncates when another is taking EX lock against
+ * inode lock. see ocfs2_data_convert_worker.
+ *
+ * The i_size check doesn't catch the case where nodes truncated and
+ * then re-extended the file. We'll re-check the page mapping after
+ * taking the page lock inside of ocfs2_write_begin_nolock().
+ *
+ * Let VM retry with these cases.
+ */
+ if ((page->mapping != inode->i_mapping) ||
+ (!PageUptodate(page)) ||
+ (page_offset(page) >= size))
+ goto out;
+
+ /*
+ * Call ocfs2_write_begin() and ocfs2_write_end() to take
+ * advantage of the allocation code there. We pass a write
+ * length of the whole page (chopped to i_size) to make sure
+ * the whole thing is allocated.
+ *
+ * Since we know the page is up to date, we don't have to
+ * worry about ocfs2_write_begin() skipping some buffer reads
+ * because the "write" would invalidate their data.
+ */
+ if (page->index == last_index)
+ len = ((size - 1) & ~PAGE_MASK) + 1;
+
+ err = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_MMAP,
+ &locked_page, &fsdata, di_bh, page);
+ if (err) {
+ if (err != -ENOSPC)
+ mlog_errno(err);
+ ret = vmf_error(err);
+ goto out;
+ }
+
+ if (!locked_page) {
+ ret = VM_FAULT_NOPAGE;
+ goto out;
+ }
+ err = ocfs2_write_end_nolock(mapping, pos, len, len, fsdata);
+ BUG_ON(err != len);
+ ret = VM_FAULT_LOCKED;
+out:
+ return ret;
+}
+
+static vm_fault_t ocfs2_page_mkwrite(struct vm_fault *vmf)
+{
+ struct page *page = vmf->page;
+ struct inode *inode = file_inode(vmf->vma->vm_file);
+ struct buffer_head *di_bh = NULL;
+ sigset_t oldset;
+ int err;
+ vm_fault_t ret;
+
+ sb_start_pagefault(inode->i_sb);
+ ocfs2_block_signals(&oldset);
+
+ /*
+ * The cluster locks taken will block a truncate from another
+ * node. Taking the data lock will also ensure that we don't
+ * attempt page truncation as part of a downconvert.
+ */
+ err = ocfs2_inode_lock(inode, &di_bh, 1);
+ if (err < 0) {
+ mlog_errno(err);
+ ret = vmf_error(err);
+ goto out;
+ }
+
+ /*
+ * The alloc sem should be enough to serialize with
+ * ocfs2_truncate_file() changing i_size as well as any thread
+ * modifying the inode btree.
+ */
+ down_write(&OCFS2_I(inode)->ip_alloc_sem);
+
+ ret = __ocfs2_page_mkwrite(vmf->vma->vm_file, di_bh, page);
+
+ up_write(&OCFS2_I(inode)->ip_alloc_sem);
+
+ brelse(di_bh);
+ ocfs2_inode_unlock(inode, 1);
+
+out:
+ ocfs2_unblock_signals(&oldset);
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}
+
+static const struct vm_operations_struct ocfs2_file_vm_ops = {
+ .fault = ocfs2_fault,
+ .page_mkwrite = ocfs2_page_mkwrite,
+};
+
+int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ int ret = 0, lock_level = 0;
+
+ ret = ocfs2_inode_lock_atime(file_inode(file),
+ file->f_path.mnt, &lock_level, 1);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ ocfs2_inode_unlock(file_inode(file), lock_level);
+out:
+ vma->vm_ops = &ocfs2_file_vm_ops;
+ return 0;
+}
+