| Message ID | 20160129151841.18752.6457.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9f4736fe7ca8 |
| Headers | show |
On Fri, Jan 29, 2016 at 07:18:41AM -0800, Dan Williams wrote: > 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@suse.com> > Cc: Jeff Moyer <jmoyer@redhat.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Dave Chinner <david@fromorbit.com> > Cc: Matthew Wilcox <willy@linux.intel.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Ross Zwisler <ross.zwisler@linux.intel.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Sure, makes sense. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> > --- > 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 */ >
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 */
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@suse.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- 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(-)