[PATCH 06/13] ext2: Convert to using invalidate_lock

Jan Kara
2021-05-25T13:51:26Z

Ext2 has its private dax_sem used for synchronizing page faults and
truncation. Use mapping->invalidate_lock instead as it is meant for this
purpose.

CC: <linux-ext4@vger.kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext2/ext2.h | 11 -----------
fs/ext2/file.c | 7 +++----
fs/ext2/inode.c | 12 ++++++------
fs/ext2/super.c | 3 ---
4 files changed, 9 insertions(+), 24 deletions(-)

diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index b0a694820cb7..81907a041570 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -667,9 +667,6 @@ struct ext2_inode_info {
struct rw_semaphore xattr_sem;
#endif
rwlock_t i_meta_lock;
-#ifdef CONFIG_FS_DAX
- struct rw_semaphore dax_sem;
-#endif

/*
* truncate_mutex is for serialising ext2_truncate() against
@@ -685,14 +682,6 @@ struct ext2_inode_info {
#endif
};

-#ifdef CONFIG_FS_DAX
-#define dax_sem_down_write(ext2_inode) down_write(&(ext2_inode)->dax_sem)
-#define dax_sem_up_write(ext2_inode) up_write(&(ext2_inode)->dax_sem)
-#else
-#define dax_sem_down_write(ext2_inode)
-#define dax_sem_up_write(ext2_inode)
-#endif
-
/*
* Inode dynamic state flags
*/
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index f98466acc672..cb54d77d7329 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -81,7 +81,7 @@ static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
*
* mmap_lock (MM)
* sb_start_pagefault (vfs, freeze)
- * ext2_inode_info->dax_sem
+ * address_space->invalidate_lock
* address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
* ext2_inode_info->truncate_mutex
*
@@ -91,7 +91,6 @@ static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
static vm_fault_t ext2_dax_fault(struct vm_fault *vmf)
{
struct inode *inode = file_inode(vmf->vma->vm_file);
- struct ext2_inode_info *ei = EXT2_I(inode);
vm_fault_t ret;
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
(vmf->vma->vm_flags & VM_SHARED);
@@ -100,11 +99,11 @@ static vm_fault_t ext2_dax_fault(struct vm_fault *vmf)
sb_start_pagefault(inode->i_sb);
file_update_time(vmf->vma->vm_file);
}
- down_read(&ei->dax_sem);
+ down_read(&inode->i_mapping->invalidate_lock);

ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops);

- up_read(&ei->dax_sem);
+ up_read(&inode->i_mapping->invalidate_lock);
if (write)
sb_end_pagefault(inode->i_sb);
return ret;
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 68178b2234bd..e843be0ae53c 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1175,7 +1175,7 @@ static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int de
ext2_free_data(inode, p, q);
}

-/* dax_sem must be held when calling this function */
+/* mapping->invalidate_lock must be held when calling this function */
static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
{
__le32 *i_data = EXT2_I(inode)->i_data;
@@ -1192,7 +1192,7 @@ static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);

#ifdef CONFIG_FS_DAX
- WARN_ON(!rwsem_is_locked(&ei->dax_sem));
+ WARN_ON(!rwsem_is_locked(&inode->i_mapping->invalidate_lock));
#endif

n = ext2_block_to_path(inode, iblock, offsets, NULL);
@@ -1274,9 +1274,9 @@ static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
if (ext2_inode_is_fast_symlink(inode))
return;

- dax_sem_down_write(EXT2_I(inode));
+ down_write(&inode->i_mapping->invalidate_lock);
__ext2_truncate_blocks(inode, offset);
- dax_sem_up_write(EXT2_I(inode));
+ up_write(&inode->i_mapping->invalidate_lock);
}

static int ext2_setsize(struct inode *inode, loff_t newsize)
@@ -1306,10 +1306,10 @@ static int ext2_setsize(struct inode *inode, loff_t newsize)
if (error)
return error;

- dax_sem_down_write(EXT2_I(inode));
+ down_write(&inode->i_mapping->invalidate_lock);
truncate_setsize(inode, newsize);
__ext2_truncate_blocks(inode, newsize);
- dax_sem_up_write(EXT2_I(inode));
+ up_write(&inode->i_mapping->invalidate_lock);

inode->i_mtime = inode->i_ctime = current_time(inode);
if (inode_needs_sync(inode)) {
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 21e09fbaa46f..987bcf32ed46 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -206,9 +206,6 @@ static void init_once(void *foo)
init_rwsem(&ei->xattr_sem);
#endif
mutex_init(&ei->truncate_mutex);
-#ifdef CONFIG_FS_DAX
- init_rwsem(&ei->dax_sem);
-#endif
inode_init_once(&ei->vfs_inode);
}

--
2.26.2