On Wed, Jul 31, 2019 at 04:12:44PM +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 and 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.
>
> The new FIEMAP_KERNEL_FIBMAP flag, is used to tell the filesystem
> ->fiemap interface, that the call is coming from ioctl_fibmap. The
> addition of this new flag, requires an update to fiemap_check_flags(),
> so it doesn't treat FIBMAP requests as invalid.
>
> Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> ---
>
> Changelog:
>
> 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/ext4/extents.c | 7 +++-
> fs/f2fs/data.c | 10 +++++-
> fs/gfs2/inode.c | 6 +++-
> fs/inode.c | 81 +++++++++++++++++++++++++++++++++++++++++--
> fs/ioctl.c | 40 ++++++++++++++-------
> fs/iomap.c | 2 +-
> fs/ocfs2/extent_map.c | 8 ++++-
> fs/xfs/xfs_iops.c | 5 +++
> include/linux/fs.h | 4 +++
> 9 files changed, 144 insertions(+), 19 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 436e564ebdd6..093b6a07067f 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -5001,7 +5001,9 @@ static int ext4_find_delayed_extent(struct inode *inode,
> return next_del;
> }
> /* fiemap flags we can handle specified here */
> -#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
> +#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC | \
> + FIEMAP_FLAG_XATTR| \
> + FIEMAP_KERNEL_FIBMAP)
>
> static int ext4_xattr_fiemap(struct inode *inode,
> struct fiemap_extent_info *fieinfo)
> @@ -5048,6 +5050,9 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> if (ext4_has_inline_data(inode)) {
> int has_inline = 1;
>
> + if (fieinfo->fi_flags & FIEMAP_KERNEL_FIBMAP)
> + return -EINVAL;
Wouldn't the inline data case be caught by fiemap_bmap and turned into
-EINVAL?
> +
> error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
> start, len);
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 2979ca40d192..29b6c48fb6cc 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1409,6 +1409,9 @@ static int f2fs_xattr_fiemap(struct inode *inode,
> return (err < 0 ? err : 0);
> }
>
> +#define F2FS_FIEMAP_COMPAT (FIEMAP_FLAG_SYNC | \
> + FIEMAP_FLAG_XATTR| \
> + FIEMAP_KERNEL_FIBMAP)
> int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> {
> u64 start = fieinfo->fi_start;
> @@ -1426,7 +1429,7 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> return ret;
> }
>
> - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
> + ret = fiemap_check_flags(fieinfo, F2FS_FIEMAP_COMPAT);
> if (ret)
> return ret;
>
> @@ -1438,6 +1441,11 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> }
>
> if (f2fs_has_inline_data(inode)) {
> +
> + ret = -EINVAL;
> + if (fieinfo->fi_flags & FIEMAP_KERNEL_FIBMAP)
> + goto out;
> +
> ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
> if (ret != -EAGAIN)
> goto out;
> diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
> index df31bd8ecf6f..30554b4f49c3 100644
> --- a/fs/gfs2/inode.c
> +++ b/fs/gfs2/inode.c
> @@ -2016,7 +2016,11 @@ static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> if (ret)
> goto out;
>
> - ret = iomap_fiemap(inode, fieinfo, &gfs2_iomap_ops);
> + if (gfs2_is_stuffed(ip) &&
> + (fieinfo->fi_flags & FIEMAP_KERNEL_FIBMAP))
> + ret = -EINVAL;
> + else
> + ret = iomap_fiemap(inode, fieinfo, &gfs2_iomap_ops);
>
> gfs2_glock_dq_uninit(&gh);
>
> diff --git a/fs/inode.c b/fs/inode.c
> index 824fa54d393d..02552b09e77f 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -1575,6 +1575,78 @@ 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 == 0) {
> + 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;
> +}
> +
> +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_KERNEL_FIBMAP | FIEMAP_FLAG_SYNC);
> +
> + error = inode->i_op->fiemap(inode, &fieinfo);
> +
> + if (error)
> + return error;
> +
> + if (fieinfo.fi_flags & (FIEMAP_EXTENT_UNKNOWN |
> + FIEMAP_EXTENT_ENCODED |
> + FIEMAP_EXTENT_DATA_INLINE |
> + FIEMAP_EXTENT_UNWRITTEN |
> + FIEMAP_EXTENT_SHARED))
> + 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
> @@ -1591,10 +1663,15 @@ 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..0759ac6e4c7e 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)
It's too bad that we lose the "not aligned" semantic meaning here.
> + if (flags & (FIEMAP_EXTENT_DATA_TAIL | FIEMAP_EXTENT_DATA_INLINE))
> flags |= FIEMAP_EXTENT_NOT_ALIGNED;
Why doesn't this function just call fiemap_fill_kernel_extent to fill
out the onstack @extent structure? We've now implemented "fill out out
a struct fiemap_extent" twice.
>
> 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;
> }
>
> /**
> @@ -151,13 +152,23 @@ EXPORT_SYMBOL(fiemap_fill_next_extent);
> * flags, the invalid values will be written into the fieinfo structure, and
> * -EBADR is returned, which tells ioctl_fiemap() to return those values to
> * userspace. For this reason, a return code of -EBADR should be preserved.
> + * In case ->fiemap is being used for FIBMAP calls, and the filesystem does not
> + * support it, return -EINVAL.
> *
> - * Returns 0 on success, -EBADR on bad flags.
> + * Returns 0 on success, -EBADR on bad flags, -EINVAL for an unsupported FIBMAP
> + * request.
> */
> int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
> {
> u32 incompat_flags;
>
> + if (fieinfo->fi_flags & FIEMAP_KERNEL_FIBMAP) {
> + if (fs_flags & FIEMAP_KERNEL_FIBMAP)
> + return 0;
> +
> + return -EINVAL;
> + }
> +
> incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
> if (incompat_flags) {
> fieinfo->fi_flags = incompat_flags;
> @@ -208,6 +219,10 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
> if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
> return -EINVAL;
>
> + /* Userspace has no access to this flag */
> + if (fiemap.fm_flags & FIEMAP_KERNEL_FIBMAP)
> + return -EINVAL;
> +
> error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
> &len);
> if (error)
> @@ -318,7 +333,8 @@ int __generic_block_fiemap(struct inode *inode,
> bool past_eof = false, whole_file = false;
> int ret = 0;
>
> - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
> + ret = fiemap_check_flags(fieinfo,
> + FIEMAP_FLAG_SYNC | FIEMAP_KERNEL_FIBMAP);
> if (ret)
> return ret;
>
> diff --git a/fs/iomap.c b/fs/iomap.c
> index b1e88722e10b..2b182abd18e8 100644
> --- a/fs/iomap.c
> +++ b/fs/iomap.c
> @@ -1195,7 +1195,7 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
> ctx.fi = fi;
> ctx.prev.type = IOMAP_HOLE;
>
> - ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC);
> + ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC | FIEMAP_KERNEL_FIBMAP);
> if (ret)
> return ret;
>
> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
> index e01fd38ea935..2884395f3972 100644
> --- a/fs/ocfs2/extent_map.c
> +++ b/fs/ocfs2/extent_map.c
> @@ -747,7 +747,7 @@ static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
> return 0;
> }
>
> -#define OCFS2_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
> +#define OCFS2_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC | FIEMAP_KERNEL_FIBMAP)
>
> int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> {
> @@ -756,6 +756,7 @@ 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;
> +
> struct buffer_head *di_bh = NULL;
> struct ocfs2_extent_rec rec;
> u64 map_start = fieinfo->fi_start;
> @@ -765,6 +766,11 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
> if (ret)
> return ret;
>
> + if (fieinfo->fi_flags & FIEMAP_KERNEL_FIBMAP) {
> + if (ocfs2_is_refcount_inode(inode))
> + return -EINVAL;
> + }
> +
> ret = ocfs2_inode_lock(inode, &di_bh, 0);
> if (ret) {
> mlog_errno(ret);
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index b485190b7ecd..18a798e9076b 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -1113,6 +1113,11 @@ xfs_vn_fiemap(
> struct fiemap_extent_info *fieinfo)
> {
> int error;
> + struct xfs_inode *ip = XFS_I(inode);
Would you mind fixing the indentation to match usual xfs style?
> +
> + if (fieinfo->fi_flags & FIEMAP_KERNEL_FIBMAP)
> + if (xfs_is_reflink_inode(ip) || XFS_IS_REALTIME_INODE(ip))
> + return -EINVAL;
The xfs part looks ok to me.
--D
>
> xfs_ilock(XFS_I(inode), XFS_IOLOCK_SHARED);
> if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index a8bd3c4f6d86..233e12ccb6d3 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1709,6 +1709,10 @@ extern bool may_open_dev(const struct path *path);
> typedef int (*fiemap_fill_cb)(struct fiemap_extent_info *fieinfo, u64 logical,
> u64 phys, u64 len, u32 flags);
>
> +#define FIEMAP_KERNEL_FIBMAP 0x10000000 /* FIBMAP call through FIEMAP
> + interface. This is a kernel
> + only flag */
> +
> struct fiemap_extent_info {
> unsigned int fi_flags; /* Flags as passed from user */
> u64 fi_start;
> --
> 2.20.1
>
