ext4: handle layout changes to pinned DAX mappings

Follow the lead of xfs_break_dax_layouts() and add synchronization between
operations in ext4 which remove blocks from an inode (hole punch, truncate
down, etc.) and pages which are pinned due to DAX DMA operations.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
This commit is contained in:
Ross Zwisler
2018-07-29 17:00:22 -04:00
committed by Theodore Ts'o
parent cdbf8897cb
commit 430657b6be
4 changed files with 68 additions and 0 deletions

View File

@@ -4826,6 +4826,13 @@ static long ext4_zero_range(struct file *file, loff_t offset,
* released from page cache.
*/
down_write(&EXT4_I(inode)->i_mmap_sem);
ret = ext4_break_layouts(inode);
if (ret) {
up_write(&EXT4_I(inode)->i_mmap_sem);
goto out_mutex;
}
ret = ext4_update_disksize_before_punch(inode, offset, len);
if (ret) {
up_write(&EXT4_I(inode)->i_mmap_sem);
@@ -5499,6 +5506,11 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
* page cache.
*/
down_write(&EXT4_I(inode)->i_mmap_sem);
ret = ext4_break_layouts(inode);
if (ret)
goto out_mmap;
/*
* Need to round down offset to be aligned with page size boundary
* for page size > block size.
@@ -5647,6 +5659,11 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
* page cache.
*/
down_write(&EXT4_I(inode)->i_mmap_sem);
ret = ext4_break_layouts(inode);
if (ret)
goto out_mmap;
/*
* Need to round down to align start offset to page size boundary
* for page size > block size.