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authorJan Kara <jack@suse.cz>2021-02-04 18:05:42 +0100
committerJan Kara <jack@suse.cz>2021-07-13 14:29:00 +0200
commitd4f5258eae7b38c2a28d0a7b28a6d0a8c1f9fe8e (patch)
tree9878725ed6feb4691c42d900917fe89775ee8439 /fs/ext4/file.c
parent7506ae6a7033f617ca5fea53e356fb1f7bd98010 (diff)
downloadlinux-d4f5258eae7b38c2a28d0a7b28a6d0a8c1f9fe8e.tar.gz
ext4: Convert to use mapping->invalidate_lock
Convert ext4 to use mapping->invalidate_lock instead of its private EXT4_I(inode)->i_mmap_sem. This is mostly search-and-replace. By this conversion we fix a long standing race between hole punching and read(2) / readahead(2) paths that can lead to stale page cache contents. CC: <linux-ext4@vger.kernel.org> CC: Ted Tso <tytso@mit.edu> Acked-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/ext4/file.c')
-rw-r--r--fs/ext4/file.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 816dedcbd541e..d3b4ed91aa682 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -704,22 +704,23 @@ static vm_fault_t ext4_dax_huge_fault(struct vm_fault *vmf,
*/
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
(vmf->vma->vm_flags & VM_SHARED);
+ struct address_space *mapping = vmf->vma->vm_file->f_mapping;
pfn_t pfn;
if (write) {
sb_start_pagefault(sb);
file_update_time(vmf->vma->vm_file);
- down_read(&EXT4_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock_shared(mapping);
retry:
handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
EXT4_DATA_TRANS_BLOCKS(sb));
if (IS_ERR(handle)) {
- up_read(&EXT4_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock_shared(mapping);
sb_end_pagefault(sb);
return VM_FAULT_SIGBUS;
}
} else {
- down_read(&EXT4_I(inode)->i_mmap_sem);
+ filemap_invalidate_lock_shared(mapping);
}
result = dax_iomap_fault(vmf, pe_size, &pfn, &error, &ext4_iomap_ops);
if (write) {
@@ -731,10 +732,10 @@ retry:
/* Handling synchronous page fault? */
if (result & VM_FAULT_NEEDDSYNC)
result = dax_finish_sync_fault(vmf, pe_size, pfn);
- up_read(&EXT4_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock_shared(mapping);
sb_end_pagefault(sb);
} else {
- up_read(&EXT4_I(inode)->i_mmap_sem);
+ filemap_invalidate_unlock_shared(mapping);
}
return result;
@@ -756,7 +757,7 @@ static const struct vm_operations_struct ext4_dax_vm_ops = {
#endif
static const struct vm_operations_struct ext4_file_vm_ops = {
- .fault = ext4_filemap_fault,
+ .fault = filemap_fault,
.map_pages = filemap_map_pages,
.page_mkwrite = ext4_page_mkwrite,
};