diff mbox series

[8/8] fs: move fiemap range validation into the file systems instances

Message ID 20200427095858.1440608-9-hch@lst.de
State Not Applicable
Headers show
Series [1/8] ext4: fix EXT4_MAX_LOGICAL_BLOCK macro | expand

Commit Message

Christoph Hellwig April 27, 2020, 9:58 a.m. UTC 
Replace fiemap_check_flags with a fiemap_validate helpers that also takes
the inode and mapped range, and performs the sanity check and truncation
previously done in fiemap_check_range.  This way the validation is inside
the file system itself and thus properly works for the stacked overlayfs
case as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/filesystems/fiemap.txt |  8 ++---
 fs/btrfs/inode.c                     |  2 +-
 fs/cifs/smb2ops.c                    |  3 +-
 fs/ext4/extents.c                    |  5 +--
 fs/f2fs/data.c                       |  3 +-
 fs/ioctl.c                           | 51 +++++++++++-----------------
 fs/iomap/fiemap.c                    |  2 +-
 fs/nilfs2/inode.c                    |  2 +-
 fs/ocfs2/extent_map.c                |  3 +-
 include/linux/fiemap.h               |  3 +-
 10 files changed, 37 insertions(+), 45 deletions(-)
diff mbox series

Patch

diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt
index ac87e6fda842b..cf757a9191ef2 100644
--- a/Documentation/filesystems/fiemap.txt
+++ b/Documentation/filesystems/fiemap.txt
@@ -203,15 +203,13 @@  EINTR once fatal signal received.
 
 
 Flag checking should be done at the beginning of the ->fiemap callback via the
-fiemap_check_flags() helper:
-
-int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
+fiemap_validate() helper.
 
 The struct fieinfo should be passed in as received from ioctl_fiemap(). The
 set of fiemap flags which the fs understands should be passed via fs_flags. If
-fiemap_check_flags finds invalid user flags, it will place the bad values in
+fiemap_validate finds invalid user flags, it will place the bad values in
 fieinfo->fi_flags and return -EBADR. If the file system gets -EBADR, from
-fiemap_check_flags(), it should immediately exit, returning that error back to
+fiemap_validate(), it should immediately exit, returning that error back to
 ioctl_fiemap().
 
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 320d1062068d3..8382b9edcbb09 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8250,7 +8250,7 @@  static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 {
 	int	ret;
 
-	ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
+	ret = fiemap_validate(inode, fieinfo, start, &len, BTRFS_FIEMAP_FLAGS);
 	if (ret)
 		return ret;
 
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 09047f1ddfb66..bf00329e720e4 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3408,7 +3408,8 @@  static int smb3_fiemap(struct cifs_tcon *tcon,
 	int i, num, rc, flags, last_blob;
 	u64 next;
 
-	if (fiemap_check_flags(fei, FIEMAP_FLAG_SYNC))
+	if (fiemap_validate(cfile->dentry->d_inode, fei, start, &len,
+			FIEMAP_FLAG_SYNC))
 		return -EBADR;
 
 	xid = get_xid();
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index a41ae7c510170..4541ff2ecc469 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4908,8 +4908,9 @@  int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
 	}
 
-	if (fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC))
-		return -EBADR;
+	error = fiemap_validate(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC);
+	if (error)
+		return error;
 
 	error = ext4_fiemap_check_ranges(inode, start, &len);
 	if (error)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 25abbbb65ba09..a33e03ecd5e89 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1825,7 +1825,8 @@  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_validate(inode, fieinfo, start, &len,
+			FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
 	if (ret)
 		return ret;
 
diff --git a/fs/ioctl.c b/fs/ioctl.c
index cbc84e23d00bd..11e95fa010ae8 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -141,8 +141,11 @@  int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
 EXPORT_SYMBOL(fiemap_fill_next_extent);
 
 /**
- * fiemap_check_flags - check validity of requested flags for fiemap
+ * fiemap_validate - check validity of requested flags for fiemap
+ * @inode:	Inode to operate on
  * @fieinfo:	Fiemap context passed into ->fiemap
+ * @start:	Start of the mapped range
+ * @len:	Length of the mapped range, can be truncated by this function.
  * @fs_flags:	Set of fiemap flags that the file system understands
  *
  * Called from file system ->fiemap callback. This will compute the
@@ -154,48 +157,38 @@  EXPORT_SYMBOL(fiemap_fill_next_extent);
  *
  * Returns 0 on success, -EBADR on bad flags.
  */
-int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
+int fiemap_validate(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		u64 start, u64 *len, u32 fs_flags)
 {
+	u64 maxbytes = inode->i_sb->s_maxbytes;
 	u32 incompat_flags;
 
-	incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
-	if (incompat_flags) {
-		fieinfo->fi_flags = incompat_flags;
-		return -EBADR;
-	}
-	return 0;
-}
-EXPORT_SYMBOL(fiemap_check_flags);
-
-static int fiemap_check_ranges(struct super_block *sb,
-			       u64 start, u64 len, u64 *new_len)
-{
-	u64 maxbytes = (u64) sb->s_maxbytes;
-
-	*new_len = len;
-
-	if (len == 0)
+	if (*len == 0)
 		return -EINVAL;
-
 	if (start > maxbytes)
 		return -EFBIG;
 
 	/*
 	 * Shrink request scope to what the fs can actually handle.
 	 */
-	if (len > maxbytes || (maxbytes - len) < start)
-		*new_len = maxbytes - start;
+	if (*len > maxbytes || (maxbytes - *len) < start)
+		*len = maxbytes - start;
+
 
+	incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
+	if (incompat_flags) {
+		fieinfo->fi_flags = incompat_flags;
+		return -EBADR;
+	}
 	return 0;
 }
+EXPORT_SYMBOL(fiemap_validate);
 
 static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
 {
 	struct fiemap fiemap;
 	struct fiemap_extent_info fieinfo = { 0, };
 	struct inode *inode = file_inode(filp);
-	struct super_block *sb = inode->i_sb;
-	u64 len;
 	int error;
 
 	if (!inode->i_op->fiemap)
@@ -207,11 +200,6 @@  static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
 	if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
 		return -EINVAL;
 
-	error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
-				    &len);
-	if (error)
-		return error;
-
 	fieinfo.fi_flags = fiemap.fm_flags;
 	fieinfo.fi_extents_max = fiemap.fm_extent_count;
 	fieinfo.fi_extents_start = ufiemap->fm_extents;
@@ -224,7 +212,8 @@  static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap)
 	if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
 		filemap_write_and_wait(inode->i_mapping);
 
-	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len);
+	error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start,
+			fiemap.fm_length);
 	fiemap.fm_flags = fieinfo.fi_flags;
 	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
@@ -312,7 +301,7 @@  static 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_validate(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC);
 	if (ret)
 		return ret;
 
diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c
index dd04e4added15..eb21a483ee776 100644
--- a/fs/iomap/fiemap.c
+++ b/fs/iomap/fiemap.c
@@ -75,7 +75,7 @@  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_validate(inode, fi, start, &len, FIEMAP_FLAG_SYNC);
 	if (ret)
 		return ret;
 
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 6e1aca38931f3..93402e7fd2104 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -1006,7 +1006,7 @@  int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	unsigned int blkbits = inode->i_blkbits;
 	int ret, n;
 
-	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
+	ret = fiemap_validate(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC);
 	if (ret)
 		return ret;
 
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index e3e2d1b2af51a..5b6c2b52a68bd 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -746,7 +746,8 @@  int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	struct buffer_head *di_bh = NULL;
 	struct ocfs2_extent_rec rec;
 
-	ret = fiemap_check_flags(fieinfo, OCFS2_FIEMAP_FLAGS);
+	ret = fiemap_validate(inode, fieinfo, map_start, &map_len,
+			OCFS2_FIEMAP_FLAGS);
 	if (ret)
 		return ret;
 
diff --git a/include/linux/fiemap.h b/include/linux/fiemap.h
index 240d4f7d9116a..a5b328bbb69b6 100644
--- a/include/linux/fiemap.h
+++ b/include/linux/fiemap.h
@@ -13,9 +13,10 @@  struct fiemap_extent_info {
 							fiemap_extent array */
 };
 
+int fiemap_validate(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		u64 start, u64 *len, u32 fs_flags);
 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
 			    u64 phys, u64 len, u32 flags);
-int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
 
 int generic_block_fiemap(struct inode *inode,
 		struct fiemap_extent_info *fieinfo, u64 start, u64 len,