On Wed, Sep 11, 2019 at 03:43:14PM +0200, Carlos Maiolino wrote:
> Enables the usage of FIEMAP ioctl infrastructure to handle FIBMAP calls.
> From now on, ->bmap() methods can start to be removed from filesystems
> which already provides ->fiemap().
>
> This adds a new helper - bmap_fiemap() - which is used to fill in the
> fiemap request, call into the underlying filesystem, check the flags
> set in the extent requested.
>
> Add a new fiemap fill extent callback to handle the in-kernel only
> fiemap_extent structure used for FIBMAP.
>
> Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> ---
>
> With the removal of FIEMAP_KERNEL_FIBMAP flag in this version, we hide
> from the filesystem whether the call is coming from FIEMAP, or FIBMAP.
>
> In this way, filesystems that previously did not support FIBMAP (but
> supports FIEMAP), may start to support it. It *may* be an issue for
> filesystems like btrfs, where we can't say for sure on which device the
> requested block resides in. But well, this is also true for FIEMAP
> requests.
> At a first glance, I didn't see any harm in having FIBMAP enabled in
> btrfs, my first worry was about bootloaders trying to use it, but I
> don't think it will change much in practice.
>
> Changelog:
>
> V6:
> - Fix sparse warning on fiemal_fill_kernel_extent:
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> - Fix conflict in ext4
> - Remove the FIEMAP_KERNEL_FIBMAP flag and let the
> caller decide whether to reply user's FIBMAP call
> based on the FIEMAP flags returned by the filesystem,
> suggested by Christoph.
>
> V5:
> - Properly rebase against 5.3
> - Fix xfs coding style
> - Use xfs_is_cow_inode() check in xfs_vn_fiemap.
> - It needs xfs_reflink.h, but maybe it's better to move
> static calls into xfs_inode.h
> - Fix small conflict due indentation update in xfs_vn_fiemap
> V4:
> - Fix if conditional in bmap()
> - Add filesystem-specific modifications
> V3:
> - Add FIEMAP_EXTENT_SHARED to the list of invalid extents in
> bmap_fiemap()
> - Rename fi_extents_start to fi_cb_data
> - Use if conditional instead of ternary operator
> - Make fiemap_fill_* callbacks static (which required the
> removal of some macros
> - Set FIEMAP_FLAG_SYNC when calling in ->fiemap method from
> fibmap
> - Add FIEMAP_KERNEL_FIBMAP flag, to identify the usage of fiemap
> infrastructure for fibmap calls, defined in fs.h so it's not
> exported to userspace.
> - Update fiemap_check_flags() to understand FIEMAP_KERNEL_FIBMAP
> - Update filesystems supporting both FIBMAP and FIEMAP, which
> need extra checks on FIBMAP calls
>
> V2:
> - Now based on the updated fiemap_extent_info,
> - move the fiemap call itself to a new helper
>
> fs/inode.c | 84 +++++++++++++++++++++++++++++++++++++++++--
> fs/ioctl.c | 21 +++++------
> fs/ocfs2/extent_map.c | 1 +
> 3 files changed, 94 insertions(+), 12 deletions(-)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index 0a20aaa572f2..ab33d16bc29d 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -1591,6 +1591,81 @@ void iput(struct inode *inode)
> }
> EXPORT_SYMBOL(iput);
>
> +static int fiemap_fill_kernel_extent(struct fiemap_extent_info *fieinfo,
> + u64 logical, u64 phys, u64 len, u32 flags)
> +{
> + struct fiemap_extent *extent = fieinfo->fi_cb_data;
> +
> + /* only count the extents */
> + if (!fieinfo->fi_cb_data) {
> + fieinfo->fi_extents_mapped++;
> + goto out;
> + }
> +
> + if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
> + return 1;
> +
> + if (flags & FIEMAP_EXTENT_DELALLOC)
> + flags |= FIEMAP_EXTENT_UNKNOWN;
> + if (flags & FIEMAP_EXTENT_DATA_ENCRYPTED)
> + flags |= FIEMAP_EXTENT_ENCODED;
> + if (flags & (FIEMAP_EXTENT_DATA_TAIL | FIEMAP_EXTENT_DATA_INLINE))
> + flags |= FIEMAP_EXTENT_NOT_ALIGNED;
> +
> + extent->fe_logical = logical;
> + extent->fe_physical = phys;
> + extent->fe_length = len;
> + extent->fe_flags = flags;
> +
> + fieinfo->fi_extents_mapped++;
> +
> + if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
> + return 1;
> +
> +out:
> + if (flags & FIEMAP_EXTENT_LAST)
> + return 1;
> + return 0;
> +}
> +
> +#define FIBMAP_INCOMPAT_FLAGS \
> + (FIEMAP_EXTENT_UNKNOWN | FIEMAP_EXTENT_DELALLOC | \
> + FIEMAP_EXTENT_ENCODED | FIEMAP_EXTENT_DATA_ENCRYPTED | \
> + FIEMAP_EXTENT_NOT_ALIGNED | FIEMAP_EXTENT_DATA_INLINE | \
> + FIEMAP_EXTENT_DATA_TAIL | FIEMAP_EXTENT_UNWRITTEN | \
> + FIEMAP_EXTENT_SHARED)
> +
> +static int bmap_fiemap(struct inode *inode, sector_t *block)
> +{
> + struct fiemap_extent_info fieinfo = { 0, };
> + struct fiemap_extent fextent;
> + u64 start = *block << inode->i_blkbits;
> + int error = -EINVAL;
> +
> + fextent.fe_logical = 0;
> + fextent.fe_physical = 0;
> + fieinfo.fi_extents_max = 1;
> + fieinfo.fi_extents_mapped = 0;
> + fieinfo.fi_cb_data = &fextent;
> + fieinfo.fi_start = start;
> + fieinfo.fi_len = 1 << inode->i_blkbits;
> + fieinfo.fi_cb = fiemap_fill_kernel_extent;
> + fieinfo.fi_flags = FIEMAP_FLAG_SYNC;
> +
> + error = inode->i_op->fiemap(inode, &fieinfo);
> +
Unnecessary blank line?
> + if (error)
> + return error;
> +
> + if (fextent.fe_flags & FIBMAP_INCOMPAT_FLAGS)
> + return -EINVAL;
> +
> + *block = (fextent.fe_physical +
> + (start - fextent.fe_logical)) >> inode->i_blkbits;
> +
> + return error;
> +}
> +
> /**
> * bmap - find a block number in a file
> * @inode: inode owning the block number being requested
> @@ -1607,10 +1682,15 @@ EXPORT_SYMBOL(iput);
> */
> int bmap(struct inode *inode, sector_t *block)
> {
> - if (!inode->i_mapping->a_ops->bmap)
> + if (inode->i_op->fiemap)
> + return bmap_fiemap(inode, block);
> +
> + if (inode->i_mapping->a_ops->bmap)
> + *block = inode->i_mapping->a_ops->bmap(inode->i_mapping,
> + *block);
> + else
> return -EINVAL;
>
> - *block = inode->i_mapping->a_ops->bmap(inode->i_mapping, *block);
> return 0;
> }
> EXPORT_SYMBOL(bmap);
> diff --git a/fs/ioctl.c b/fs/ioctl.c
> index d72696c222de..fbfd631ba3cb 100644
> --- a/fs/ioctl.c
> +++ b/fs/ioctl.c
> @@ -77,11 +77,8 @@ static int ioctl_fibmap(struct file *filp, int __user *p)
> return error;
> }
>
> -#define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC)
> -#define SET_NO_UNMOUNTED_IO_FLAGS (FIEMAP_EXTENT_DATA_ENCRYPTED)
> -#define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
> -int fiemap_fill_user_extent(struct fiemap_extent_info *fieinfo, u64 logical,
> - u64 phys, u64 len, u32 flags)
> +static int fiemap_fill_user_extent(struct fiemap_extent_info *fieinfo,
> + u64 logical, u64 phys, u64 len, u32 flags)
> {
> struct fiemap_extent extent;
> struct fiemap_extent __user *dest = fieinfo->fi_cb_data;
> @@ -89,17 +86,17 @@ int fiemap_fill_user_extent(struct fiemap_extent_info *fieinfo, u64 logical,
> /* only count the extents */
> if (fieinfo->fi_extents_max == 0) {
> fieinfo->fi_extents_mapped++;
> - return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
> + goto out;
> }
>
> if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
> return 1;
>
> - if (flags & SET_UNKNOWN_FLAGS)
> + if (flags & FIEMAP_EXTENT_DELALLOC)
> flags |= FIEMAP_EXTENT_UNKNOWN;
> - if (flags & SET_NO_UNMOUNTED_IO_FLAGS)
> + if (flags & FIEMAP_EXTENT_DATA_ENCRYPTED)
> flags |= FIEMAP_EXTENT_ENCODED;
> - if (flags & SET_NOT_ALIGNED_FLAGS)
> + if (flags & (FIEMAP_EXTENT_DATA_TAIL | FIEMAP_EXTENT_DATA_INLINE))
> flags |= FIEMAP_EXTENT_NOT_ALIGNED;
>
> memset(&extent, 0, sizeof(extent));
> @@ -115,7 +112,11 @@ int fiemap_fill_user_extent(struct fiemap_extent_info *fieinfo, u64 logical,
> fieinfo->fi_extents_mapped++;
> if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
> return 1;
> - return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
> +
> +out:
> + if (flags & FIEMAP_EXTENT_LAST)
> + return 1;
> + return 0;
> }
>
> /**
> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
> index 1a5b6af62ee0..0dd838615d14 100644
> --- a/fs/ocfs2/extent_map.c
> +++ b/fs/ocfs2/extent_map.c
> @@ -743,6 +743,7 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> unsigned int hole_size;
> struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
> u64 len_bytes, phys_bytes, virt_bytes;
> +
Unnecessary code change...
With that fixed up, I'd say:
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> struct buffer_head *di_bh = NULL;
> struct ocfs2_extent_rec rec;
> u64 map_start = fieinfo->fi_start;
> --
> 2.20.1
>
