Dynamically enabling DAX requires that the page cache first be flushed
and invalidated. This must occur atomically with the change of DAX mode
otherwise we confuse the fsync/msync tracking and violate data
durability guarantees. Eliminate the possibilty of DAX-disabled to
DAX-enabled transitions for now and revisit this for the next cycle.
Cc: Jan Kara <jack@xxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
block/ioctl.c | 38 --------------------------------------
fs/block_dev.c | 28 ----------------------------
include/linux/fs.h | 3 ---
include/uapi/linux/fs.h | 1 -
4 files changed, 70 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c
index 77f5d17779d6..d8996bbd7f12 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -434,42 +434,6 @@ bool blkdev_dax_capable(struct block_device *bdev)
return true;
}
-
-static int blkdev_daxset(struct block_device *bdev, unsigned long argp)
-{
- unsigned long arg;
- int rc = 0;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EACCES;
-
- if (get_user(arg, (int __user *)(argp)))
- return -EFAULT;
- arg = !!arg;
- if (arg == !!(bdev->bd_inode->i_flags & S_DAX))
- return 0;
-
- if (arg)
- arg = S_DAX;
-
- if (arg && !blkdev_dax_capable(bdev))
- return -ENOTTY;
-
- inode_lock(bdev->bd_inode);
- if (bdev->bd_map_count == 0)
- inode_set_flags(bdev->bd_inode, arg, S_DAX);
- else
- rc = -EBUSY;
- inode_unlock(bdev->bd_inode);
- return rc;
-}
-#else
-static int blkdev_daxset(struct block_device *bdev, int arg)
-{
- if (arg)
- return -ENOTTY;
- return 0;
-}
#endif
static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
@@ -634,8 +598,6 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
case BLKTRACESETUP:
case BLKTRACETEARDOWN:
return blk_trace_ioctl(bdev, cmd, argp);
- case BLKDAXSET:
- return blkdev_daxset(bdev, arg);
case BLKDAXGET:
return put_int(arg, !!(bdev->bd_inode->i_flags & S_DAX));
break;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7b9cd49622b1..afb437484362 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1736,37 +1736,13 @@ static int blkdev_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
return __dax_pmd_fault(vma, addr, pmd, flags, blkdev_get_block, NULL);
}
-static void blkdev_vm_open(struct vm_area_struct *vma)
-{
- struct inode *bd_inode = bdev_file_inode(vma->vm_file);
- struct block_device *bdev = I_BDEV(bd_inode);
-
- inode_lock(bd_inode);
- bdev->bd_map_count++;
- inode_unlock(bd_inode);
-}
-
-static void blkdev_vm_close(struct vm_area_struct *vma)
-{
- struct inode *bd_inode = bdev_file_inode(vma->vm_file);
- struct block_device *bdev = I_BDEV(bd_inode);
-
- inode_lock(bd_inode);
- bdev->bd_map_count--;
- inode_unlock(bd_inode);
-}
-
static const struct vm_operations_struct blkdev_dax_vm_ops = {
- .open = blkdev_vm_open,
- .close = blkdev_vm_close,
.fault = blkdev_dax_fault,
.pmd_fault = blkdev_dax_pmd_fault,
.pfn_mkwrite = blkdev_dax_fault,
};
static const struct vm_operations_struct blkdev_default_vm_ops = {
- .open = blkdev_vm_open,
- .close = blkdev_vm_close,
.fault = filemap_fault,
.map_pages = filemap_map_pages,
};
@@ -1774,18 +1750,14 @@ static const struct vm_operations_struct blkdev_default_vm_ops = {
static int blkdev_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *bd_inode = bdev_file_inode(file);
- struct block_device *bdev = I_BDEV(bd_inode);
file_accessed(file);
- inode_lock(bd_inode);
- bdev->bd_map_count++;
if (IS_DAX(bd_inode)) {
vma->vm_ops = &blkdev_dax_vm_ops;
vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
} else {
vma->vm_ops = &blkdev_default_vm_ops;
}
- inode_unlock(bd_inode);
return 0;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b10002d4a5f5..ae681002100a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -484,9 +484,6 @@ struct block_device {
int bd_fsfreeze_count;
/* Mutex for freeze */
struct mutex bd_fsfreeze_mutex;
-#ifdef CONFIG_FS_DAX
- int bd_map_count;
-#endif
};
/*
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 41e0433b4a83..149bec83a907 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -222,7 +222,6 @@ struct fsxattr {
#define BLKSECDISCARD _IO(0x12,125)
#define BLKROTATIONAL _IO(0x12,126)
#define BLKZEROOUT _IO(0x12,127)
-#define BLKDAXSET _IO(0x12,128)
#define BLKDAXGET _IO(0x12,129)
#define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
--
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