[PATCH 0/9 V3] New ->fiemap infrastructure and ->bmap removal

[PATCH 0/9 V3] New ->fiemap infrastructure and ->bmap removal

[Carlos Maiolino]

Hi.

This is the 3rd version of the complete series with the goal to remove ->bmap
interface completely, in lieu of FIEMAP.

This new version has been slightly modified in comparison with the second one,
based on reviews of the second version. My apologies if I forgot to update
anything based on previous discussion.

Patch 1-3 have no difference from the previous version, and Christoph's
Reviewed-by has been kept.

Patch 4 is a V3 of the previous set, Containing just a small update renaming a
variable.

Patches 5-6 are the same from previous version, including now Christoph's
Reviewed-by tahg.

Patch 7 contains a merge of patches 7 and 8 from the previous version, a small
conflict fix when rebasing on top of linux-next, and a rename of the pointer
holding the fiemap callback.

Patch 8 is the biggest change in this patchset, and has been flagged as a RFC
giving the fact we have not reached a decision on how the replacement of ->bmap
by ->fiemap should be done. The patch description has all details.

Patch 9 is a V2 from the previous patchset, including removal of iomap unused
functions.

As always, comments are much appreciated.

Cheers


Carlos Maiolino (9):
  fs: Enable bmap() function to properly return errors
  cachefiles: drop direct usage of ->bmap method.
  ecryptfs: drop direct calls to ->bmap
  fibmap: Use bmap instead of ->bmap method in ioctl_fibmap
  fs: Move start and length fiemap fields into fiemap_extent_info
  iomap: Remove length and start fields from iomap_fiemap
  fiemap: Use a callback to fill fiemap extents
  Use FIEMAP for FIBMAP calls
  xfs: Get rid of ->bmap

 drivers/md/md-bitmap.c |  16 ++++--
 fs/bad_inode.c         |   3 +-
 fs/btrfs/inode.c       |   5 +-
 fs/cachefiles/rdwr.c   |  27 ++++-----
 fs/ecryptfs/mmap.c     |  16 ++----
 fs/ext2/ext2.h         |   3 +-
 fs/ext2/inode.c        |   6 +-
 fs/ext4/ext4.h         |   3 +-
 fs/ext4/extents.c      |  15 +++--
 fs/f2fs/data.c         |  10 +++-
 fs/f2fs/f2fs.h         |   3 +-
 fs/gfs2/inode.c        |   5 +-
 fs/hpfs/file.c         |   4 +-
 fs/inode.c             | 106 +++++++++++++++++++++++++++++-----
 fs/ioctl.c             | 126 ++++++++++++++++++++++++++---------------
 fs/iomap.c             |  40 ++-----------
 fs/jbd2/journal.c      |  22 ++++---
 fs/nilfs2/inode.c      |   5 +-
 fs/nilfs2/nilfs.h      |   3 +-
 fs/ocfs2/extent_map.c  |  13 ++++-
 fs/ocfs2/extent_map.h  |   3 +-
 fs/overlayfs/inode.c   |   5 +-
 fs/xfs/xfs_aops.c      |  24 --------
 fs/xfs/xfs_iops.c      |  19 ++++---
 fs/xfs/xfs_trace.h     |   1 -
 include/linux/fs.h     |  33 +++++++----
 include/linux/iomap.h  |   2 +-
 mm/page_io.c           |  11 ++--
 28 files changed, 309 insertions(+), 220 deletions(-)

-- 
2.17.2

[PATCH 1/9] fs: Enable bmap() function to properly return errors

[Carlos Maiolino]

By now, bmap() will either return the physical block number related to
the requested file offset or 0 in case of error or the requested offset
maps into a hole.
This patch makes the needed changes to enable bmap() to proper return
errors, using the return value as an error return, and now, a pointer
must be passed to bmap() to be filled with the mapped physical block.

It will change the behavior of bmap() on return:

- negative value in case of error
- zero on success or map fell into a hole

In case of a hole, the *block will be zero too

Since this is a prep patch, by now, the only error return is -EINVAL if
->bmap doesn't exist.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 drivers/md/md-bitmap.c | 16 ++++++++++------
 fs/inode.c             | 30 +++++++++++++++++-------------
 fs/jbd2/journal.c      | 22 +++++++++++++++-------
 include/linux/fs.h     |  2 +-
 mm/page_io.c           | 11 +++++++----
 5 files changed, 50 insertions(+), 31 deletions(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 1cd4f991792c..0668b2dd290e 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -363,7 +363,7 @@ static int read_page(struct file *file, unsigned long index,
 	int ret = 0;
 	struct inode *inode = file_inode(file);
 	struct buffer_head *bh;
-	sector_t block;
+	sector_t block, blk_cur;
 
 	pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
 		 (unsigned long long)index << PAGE_SHIFT);
@@ -374,17 +374,21 @@ static int read_page(struct file *file, unsigned long index,
 		goto out;
 	}
 	attach_page_buffers(page, bh);
-	block = index << (PAGE_SHIFT - inode->i_blkbits);
+	blk_cur = index << (PAGE_SHIFT - inode->i_blkbits);
 	while (bh) {
+		block = blk_cur;
+
 		if (count == 0)
 			bh->b_blocknr = 0;
 		else {
-			bh->b_blocknr = bmap(inode, block);
-			if (bh->b_blocknr == 0) {
-				/* Cannot use this file! */
+			ret = bmap(inode, &block);
+			if (ret || !block) {
 				ret = -EINVAL;
+				bh->b_blocknr = 0;
 				goto out;
 			}
+
+			bh->b_blocknr = block;
 			bh->b_bdev = inode->i_sb->s_bdev;
 			if (count < (1<<inode->i_blkbits))
 				count = 0;
@@ -398,7 +402,7 @@ static int read_page(struct file *file, unsigned long index,
 			set_buffer_mapped(bh);
 			submit_bh(REQ_OP_READ, 0, bh);
 		}
-		block++;
+		blk_cur++;
 		bh = bh->b_this_page;
 	}
 	page->index = index;
diff --git a/fs/inode.c b/fs/inode.c
index 0cd47fe0dbe5..db681d310465 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1580,21 +1580,25 @@ EXPORT_SYMBOL(iput);
 
 /**
  *	bmap	- find a block number in a file
- *	@inode: inode of file
- *	@block: block to find
- *
- *	Returns the block number on the device holding the inode that
- *	is the disk block number for the block of the file requested.
- *	That is, asked for block 4 of inode 1 the function will return the
- *	disk block relative to the disk start that holds that block of the
- *	file.
+ *	@inode:  inode owning the block number being requested
+ *	@*block: pointer containing the block to find
+ *
+ *	Replaces the value in *block with the block number on the device holding
+ *	corresponding to the requested block number in the file.
+ *	That is, asked for block 4 of inode 1 the function will replace the
+ *	4 in *block, with disk block relative to the disk start that holds that
+ *	block of the file.
+ *
+ *	Returns -EINVAL in case of error, 0 otherwise. If mapping falls into a
+ *	hole, returns 0 and *block is also set to 0.
  */
-sector_t bmap(struct inode *inode, sector_t block)
+int bmap(struct inode *inode, sector_t *block)
 {
-	sector_t res = 0;
-	if (inode->i_mapping->a_ops->bmap)
-		res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block);
-	return res;
+	if (!inode->i_mapping->a_ops->bmap)
+		return -EINVAL;
+
+	*block = inode->i_mapping->a_ops->bmap(inode->i_mapping, *block);
+	return 0;
 }
 EXPORT_SYMBOL(bmap);
 
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 8ef6b6daaa7a..7acaf6f55404 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -814,18 +814,23 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
 {
 	int err = 0;
 	unsigned long long ret;
+	sector_t block = 0;
 
 	if (journal->j_inode) {
-		ret = bmap(journal->j_inode, blocknr);
-		if (ret)
-			*retp = ret;
-		else {
+		block = blocknr;
+		ret = bmap(journal->j_inode, &block);
+
+		if (ret || !block) {
 			printk(KERN_ALERT "%s: journal block not found "
 					"at offset %lu on %s\n",
 			       __func__, blocknr, journal->j_devname);
 			err = -EIO;
 			__journal_abort_soft(journal, err);
+
+		} else {
+			*retp = block;
 		}
+
 	} else {
 		*retp = blocknr; /* +journal->j_blk_offset */
 	}
@@ -1251,11 +1256,14 @@ journal_t *jbd2_journal_init_dev(struct block_device *bdev,
 journal_t *jbd2_journal_init_inode(struct inode *inode)
 {
 	journal_t *journal;
+	sector_t blocknr;
 	char *p;
-	unsigned long long blocknr;
+	int err = 0;
+
+	blocknr = 0;
+	err = bmap(inode, &blocknr);
 
-	blocknr = bmap(inode, 0);
-	if (!blocknr) {
+	if (err || !blocknr) {
 		pr_err("%s: Cannot locate journal superblock\n",
 			__func__);
 		return NULL;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d005e38ce278..d63ed037c4b9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2790,7 +2790,7 @@ static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
 extern void emergency_sync(void);
 extern void emergency_remount(void);
 #ifdef CONFIG_BLOCK
-extern sector_t bmap(struct inode *, sector_t);
+extern int bmap(struct inode *, sector_t *);
 #endif
 extern int notify_change(struct dentry *, struct iattr *, struct inode **);
 extern int inode_permission(struct inode *, int);
diff --git a/mm/page_io.c b/mm/page_io.c
index 2e8019d0e048..dc878c47916c 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -177,8 +177,9 @@ int generic_swapfile_activate(struct swap_info_struct *sis,
 
 		cond_resched();
 
-		first_block = bmap(inode, probe_block);
-		if (first_block == 0)
+		first_block = probe_block;
+		ret = bmap(inode, &first_block);
+		if (ret || !first_block)
 			goto bad_bmap;
 
 		/*
@@ -193,9 +194,11 @@ int generic_swapfile_activate(struct swap_info_struct *sis,
 					block_in_page++) {
 			sector_t block;
 
-			block = bmap(inode, probe_block + block_in_page);
-			if (block == 0)
+			block = probe_block + block_in_page;
+			ret = bmap(inode, &block);
+			if (ret || !block)
 				goto bad_bmap;
+
 			if (block != first_block + block_in_page) {
 				/* Discontiguity */
 				probe_block++;
-- 
2.17.2

[PATCH 2/9] cachefiles: drop direct usage of ->bmap method.

[Carlos Maiolino]

Replace the direct usage of ->bmap method by a bmap() call.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/cachefiles/rdwr.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index 8a577409d030..1a74aa978056 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -400,7 +400,7 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 	struct cachefiles_object *object;
 	struct cachefiles_cache *cache;
 	struct inode *inode;
-	sector_t block0, block;
+	sector_t block;
 	unsigned shift;
 	int ret;
 
@@ -416,7 +416,6 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 
 	inode = d_backing_inode(object->backer);
 	ASSERT(S_ISREG(inode->i_mode));
-	ASSERT(inode->i_mapping->a_ops->bmap);
 	ASSERT(inode->i_mapping->a_ops->readpages);
 
 	/* calculate the shift required to use bmap */
@@ -432,12 +431,14 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 	 *   enough for this as it doesn't indicate errors, but it's all we've
 	 *   got for the moment
 	 */
-	block0 = page->index;
-	block0 <<= shift;
+	block = page->index;
+	block <<= shift;
+
+	ret = bmap(inode, &block);
+	ASSERT(!ret);
 
-	block = inode->i_mapping->a_ops->bmap(inode->i_mapping, block0);
 	_debug("%llx -> %llx",
-	       (unsigned long long) block0,
+	       (unsigned long long) (page->index << shift),
 	       (unsigned long long) block);
 
 	if (block) {
@@ -715,7 +716,6 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 
 	inode = d_backing_inode(object->backer);
 	ASSERT(S_ISREG(inode->i_mode));
-	ASSERT(inode->i_mapping->a_ops->bmap);
 	ASSERT(inode->i_mapping->a_ops->readpages);
 
 	/* calculate the shift required to use bmap */
@@ -732,7 +732,7 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 
 	ret = space ? -ENODATA : -ENOBUFS;
 	list_for_each_entry_safe(page, _n, pages, lru) {
-		sector_t block0, block;
+		sector_t block;
 
 		/* we assume the absence or presence of the first block is a
 		 * good enough indication for the page as a whole
@@ -740,13 +740,14 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 		 *   good enough for this as it doesn't indicate errors, but
 		 *   it's all we've got for the moment
 		 */
-		block0 = page->index;
-		block0 <<= shift;
+		block = page->index;
+		block <<= shift;
+
+		ret = bmap(inode, &block);
+		ASSERT(!ret);
 
-		block = inode->i_mapping->a_ops->bmap(inode->i_mapping,
-						      block0);
 		_debug("%llx -> %llx",
-		       (unsigned long long) block0,
+		       (unsigned long long) (page->index << shift),
 		       (unsigned long long) block);
 
 		if (block) {
-- 
2.17.2

[PATCH 3/9] ecryptfs: drop direct calls to ->bmap

[Carlos Maiolino]

Replace direct ->bmap calls by bmap() method.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/ecryptfs/mmap.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index cdf358b209d9..ff323dccef36 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -538,16 +538,12 @@ static int ecryptfs_write_end(struct file *file,
 
 static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
 {
-	int rc = 0;
-	struct inode *inode;
-	struct inode *lower_inode;
-
-	inode = (struct inode *)mapping->host;
-	lower_inode = ecryptfs_inode_to_lower(inode);
-	if (lower_inode->i_mapping->a_ops->bmap)
-		rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping,
-							 block);
-	return rc;
+	struct inode *lower_inode = ecryptfs_inode_to_lower(mapping->host);
+	int ret = bmap(lower_inode, &block);
+
+	if (ret)
+		return 0;
+	return block;
 }
 
 const struct address_space_operations ecryptfs_aops = {
-- 
2.17.2

[PATCH 4/9 V3] fibmap: Use bmap instead of ->bmap method in ioctl_fibmap

[Carlos Maiolino]

Now we have the possibility of proper error return in bmap, use bmap()
function in ioctl_fibmap() instead of calling ->bmap method directly.

V3:
	- Rename usr_blk to ur_block

V2:
	- Use a local sector_t variable to asign the block number
	  instead of using direct casting.
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/ioctl.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/fs/ioctl.c b/fs/ioctl.c
index fef3a6bf7c78..2c787ca6fa42 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -53,19 +53,26 @@ EXPORT_SYMBOL(vfs_ioctl);
 
 static int ioctl_fibmap(struct file *filp, int __user *p)
 {
-	struct address_space *mapping = filp->f_mapping;
-	int res, block;
+	struct inode *inode = file_inode(filp);
+	int error, ur_block;
+	sector_t block;
 
-	/* do we support this mess? */
-	if (!mapping->a_ops->bmap)
-		return -EINVAL;
 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;
-	res = get_user(block, p);
-	if (res)
-		return res;
-	res = mapping->a_ops->bmap(mapping, block);
-	return put_user(res, p);
+
+	error = get_user(ur_block, p);
+	if (error)
+		return error;
+
+	block = ur_block;
+	error = bmap(inode, &block);
+	if (error)
+		return error;
+	ur_block = block;
+
+	error = put_user(ur_block, p);
+
+	return error;
 }
 
 /**
-- 
2.17.2

[PATCH 5/9] fs: Move start and length fiemap fields into fiemap_extent_info

[Carlos Maiolino]

As the overall goal to deprecate fibmap, Christoph suggested a rework of
the ->fiemap API, in a way we could pass to it a callback to fill the
fiemap structure (one of these callbacks being fiemap_fill_next_extent).

To avoid the need to add several fields into the ->fiemap method, aggregate
everything into a single data structure, and pass it along.

This patch isn't suppose to add any functional change, only to update
filesystems providing ->fiemap() method.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/bad_inode.c        |  3 +--
 fs/btrfs/inode.c      |  5 +++--
 fs/ext2/ext2.h        |  3 +--
 fs/ext2/inode.c       |  6 ++----
 fs/ext4/ext4.h        |  3 +--
 fs/ext4/extents.c     |  8 ++++----
 fs/f2fs/data.c        |  5 +++--
 fs/f2fs/f2fs.h        |  3 +--
 fs/gfs2/inode.c       |  5 +++--
 fs/hpfs/file.c        |  4 ++--
 fs/ioctl.c            | 16 ++++++++++------
 fs/nilfs2/inode.c     |  5 +++--
 fs/nilfs2/nilfs.h     |  3 +--
 fs/ocfs2/extent_map.c |  5 +++--
 fs/ocfs2/extent_map.h |  3 +--
 fs/overlayfs/inode.c  |  5 ++---
 fs/xfs/xfs_iops.c     | 10 +++++-----
 include/linux/fs.h    | 21 +++++++++++----------
 18 files changed, 57 insertions(+), 56 deletions(-)

diff --git a/fs/bad_inode.c b/fs/bad_inode.c
index 8035d2a44561..21dfaf876814 100644
--- a/fs/bad_inode.c
+++ b/fs/bad_inode.c
@@ -120,8 +120,7 @@ static struct posix_acl *bad_inode_get_acl(struct inode *inode, int type)
 }
 
 static int bad_inode_fiemap(struct inode *inode,
-			    struct fiemap_extent_info *fieinfo, u64 start,
-			    u64 len)
+			    struct fiemap_extent_info *fieinfo)
 {
 	return -EIO;
 }
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6126de9b8b9c..35117a381783 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8628,9 +8628,10 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 
 #define BTRFS_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC)
 
-static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		__u64 start, __u64 len)
+static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
+	u64	start = fieinfo->fi_start;
+	u64	len = fieinfo->fi_len;
 	int	ret;
 
 	ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 93fcfe7bbb3b..3a020cb2a9a4 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -759,8 +759,7 @@ extern void ext2_evict_inode(struct inode *);
 extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
 extern int ext2_setattr (struct dentry *, struct iattr *);
 extern void ext2_set_inode_flags(struct inode *inode);
-extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		       u64 start, u64 len);
+extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo);
 
 /* ioctl.c */
 extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 17cdefdc62a8..a14f6fa091e8 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -855,11 +855,9 @@ const struct iomap_ops ext2_iomap_ops = {
 const struct iomap_ops ext2_iomap_ops;
 #endif /* CONFIG_FS_DAX */
 
-int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		u64 start, u64 len)
+int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
-	return generic_block_fiemap(inode, fieinfo, start, len,
-				    ext2_get_block);
+	return generic_block_fiemap(inode, fieinfo, ext2_get_block);
 }
 
 static int ext2_writepage(struct page *page, struct writeback_control *wbc)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 5012ddb6daf9..1330bd905af5 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3147,8 +3147,7 @@ extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
 extern int ext4_ext_check_inode(struct inode *inode);
 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
-extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-			__u64 start, __u64 len);
+extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo);
 extern int ext4_ext_precache(struct inode *inode);
 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
 extern int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 79d986dbf5af..c1fed5b286df 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5045,9 +5045,10 @@ static int ext4_xattr_fiemap(struct inode *inode,
 	return (error < 0 ? error : 0);
 }
 
-int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		__u64 start, __u64 len)
+int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
+	u64 start = fieinfo->fi_start;
+	u64 len = fieinfo->fi_len;
 	ext4_lblk_t start_blk;
 	int error = 0;
 
@@ -5069,8 +5070,7 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 
 	/* fallback to generic here if not in extents fmt */
 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-		return generic_block_fiemap(inode, fieinfo, start, len,
-			ext4_get_block);
+		return generic_block_fiemap(inode, fieinfo, ext4_get_block);
 
 	if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
 		return -EBADR;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index a9f12ab409ce..450f2b260c46 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1405,9 +1405,10 @@ static int f2fs_xattr_fiemap(struct inode *inode,
 	return (err < 0 ? err : 0);
 }
 
-int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		u64 start, u64 len)
+int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
+	u64 start = fieinfo->fi_start;
+	u64 len = fieinfo->fi_len;
 	struct buffer_head map_bh;
 	sector_t start_blk, last_blk;
 	pgoff_t next_pgofs;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 434fc38c9f37..46c0ddbb6b7d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3127,8 +3127,7 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio);
 void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock);
 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 			int create, int flag);
-int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-			u64 start, u64 len);
+int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo);
 bool f2fs_should_update_inplace(struct inode *inode, struct f2fs_io_info *fio);
 bool f2fs_should_update_outplace(struct inode *inode, struct f2fs_io_info *fio);
 void f2fs_invalidate_page(struct page *page, unsigned int offset,
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 998051c4aea7..5e84d5963506 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -2004,9 +2004,10 @@ static int gfs2_getattr(const struct path *path, struct kstat *stat,
 	return 0;
 }
 
-static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		       u64 start, u64 len)
+static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
+	u64 start = fieinfo->fi_start;
+	u64 len = fieinfo->fi_len;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_holder gh;
 	int ret;
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 1ecec124e76f..0eece4ae1f11 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -190,9 +190,9 @@ static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
 	return generic_block_bmap(mapping, block, hpfs_get_block);
 }
 
-static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len)
+static int hpfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
-	return generic_block_fiemap(inode, fieinfo, start, len, hpfs_get_block);
+	return generic_block_fiemap(inode, fieinfo, hpfs_get_block);
 }
 
 const struct address_space_operations hpfs_aops = {
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 2c787ca6fa42..88b000ffebf4 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -208,6 +208,8 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
 	fieinfo.fi_flags = fiemap.fm_flags;
 	fieinfo.fi_extents_max = fiemap.fm_extent_count;
 	fieinfo.fi_extents_start = ufiemap->fm_extents;
+	fieinfo.fi_start = fiemap.fm_start;
+	fieinfo.fi_len = len;
 
 	if (fiemap.fm_extent_count != 0 &&
 	    !access_ok(fieinfo.fi_extents_start,
@@ -217,7 +219,7 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
 	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_flags = fieinfo.fi_flags;
 	fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
 	if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap)))
@@ -294,9 +296,11 @@ static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
  */
 
 int __generic_block_fiemap(struct inode *inode,
-			   struct fiemap_extent_info *fieinfo, loff_t start,
-			   loff_t len, get_block_t *get_block)
+			   struct fiemap_extent_info *fieinfo,
+			   get_block_t *get_block)
 {
+	loff_t start = fieinfo->fi_start;
+	loff_t len = fieinfo->fi_len;
 	struct buffer_head map_bh;
 	sector_t start_blk, last_blk;
 	loff_t isize = i_size_read(inode);
@@ -453,12 +457,12 @@ EXPORT_SYMBOL(__generic_block_fiemap);
  */
 
 int generic_block_fiemap(struct inode *inode,
-			 struct fiemap_extent_info *fieinfo, u64 start,
-			 u64 len, get_block_t *get_block)
+			 struct fiemap_extent_info *fieinfo,
+			 get_block_t *get_block)
 {
 	int ret;
 	inode_lock(inode);
-	ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
+	ret = __generic_block_fiemap(inode, fieinfo, get_block);
 	inode_unlock(inode);
 	return ret;
 }
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 671085512e0f..1f37d086371c 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -992,9 +992,10 @@ void nilfs_dirty_inode(struct inode *inode, int flags)
 	nilfs_transaction_commit(inode->i_sb); /* never fails */
 }
 
-int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 __u64 start, __u64 len)
+int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
+	u64 start = fieinfo->fi_start;
+	u64 len = fieinfo->fi_len;
 	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 	__u64 logical = 0, phys = 0, size = 0;
 	__u32 flags = 0;
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index a2f247b6a209..55d1307ed710 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -276,8 +276,7 @@ extern int nilfs_inode_dirty(struct inode *);
 int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty);
 extern int __nilfs_mark_inode_dirty(struct inode *, int);
 extern void nilfs_dirty_inode(struct inode *, int flags);
-int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 __u64 start, __u64 len);
+int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo);
 static inline int nilfs_mark_inode_dirty(struct inode *inode)
 {
 	return __nilfs_mark_inode_dirty(inode, I_DIRTY);
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index 06cb96462bf9..e01fd38ea935 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -749,8 +749,7 @@ static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
 
 #define OCFS2_FIEMAP_FLAGS	(FIEMAP_FLAG_SYNC)
 
-int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 u64 map_start, u64 map_len)
+int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
 	int ret, is_last;
 	u32 mapping_end, cpos;
@@ -759,6 +758,8 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	u64 len_bytes, phys_bytes, virt_bytes;
 	struct buffer_head *di_bh = NULL;
 	struct ocfs2_extent_rec rec;
+	u64 map_start = fieinfo->fi_start;
+	u64 map_len = fieinfo->fi_len;
 
 	ret = fiemap_check_flags(fieinfo, OCFS2_FIEMAP_FLAGS);
 	if (ret)
diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h
index 1057586ec19f..793be96099c0 100644
--- a/fs/ocfs2/extent_map.h
+++ b/fs/ocfs2/extent_map.h
@@ -50,8 +50,7 @@ int ocfs2_get_clusters(struct inode *inode, u32 v_cluster, u32 *p_cluster,
 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
 				u64 *ret_count, unsigned int *extent_flags);
 
-int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		 u64 map_start, u64 map_len);
+int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo);
 
 int ocfs2_overwrite_io(struct inode *inode, struct buffer_head *di_bh,
 		       u64 map_start, u64 map_len);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 3b7ed5d2279c..a057b4a756cd 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -456,8 +456,7 @@ int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags)
 	return 0;
 }
 
-static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		      u64 start, u64 len)
+static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
 	int err;
 	struct inode *realinode = ovl_inode_real(inode);
@@ -471,7 +470,7 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
 		filemap_write_and_wait(realinode->i_mapping);
 
-	err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
+	err = realinode->i_op->fiemap(realinode, fieinfo,);
 	revert_creds(old_cred);
 
 	return err;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index f48ffd7a8d3e..1040e8346286 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1092,12 +1092,12 @@ xfs_vn_update_time(
 
 STATIC int
 xfs_vn_fiemap(
-	struct inode		*inode,
-	struct fiemap_extent_info *fieinfo,
-	u64			start,
-	u64			length)
+	struct inode		  *inode,
+	struct fiemap_extent_info *fieinfo)
 {
-	int			error;
+	u64	start = fieinfo->fi_start;
+	u64	length = fieinfo->fi_len;
+	int	error;
 
 	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 d63ed037c4b9..93152b3d14bf 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1694,11 +1694,14 @@ extern bool may_open_dev(const struct path *path);
  * VFS FS_IOC_FIEMAP helper definitions.
  */
 struct fiemap_extent_info {
-	unsigned int fi_flags;		/* Flags as passed from user */
-	unsigned int fi_extents_mapped;	/* Number of mapped extents */
-	unsigned int fi_extents_max;	/* Size of fiemap_extent array */
-	struct fiemap_extent __user *fi_extents_start; /* Start of
-							fiemap_extent array */
+	unsigned int	fi_flags;		/* Flags as passed from user */
+	u64		fi_start;
+	u64		fi_len;
+	unsigned int	fi_extents_mapped;	/* Number of mapped extents */
+	unsigned int	fi_extents_max;		/* Size of fiemap_extent array */
+	struct		fiemap_extent __user *fi_extents_start;	/* Start of
+								   fiemap_extent
+								   array */
 };
 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
 			    u64 phys, u64 len, u32 flags);
@@ -1829,8 +1832,7 @@ struct inode_operations {
 	int (*setattr) (struct dentry *, struct iattr *);
 	int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);
 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
-	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
-		      u64 len);
+	int (*fiemap)(struct inode *, struct fiemap_extent_info *);
 	int (*update_time)(struct inode *, struct timespec64 *, int);
 	int (*atomic_open)(struct inode *, struct dentry *,
 			   struct file *, unsigned open_flag,
@@ -3186,11 +3188,10 @@ extern int vfs_readlink(struct dentry *, char __user *, int);
 
 extern int __generic_block_fiemap(struct inode *inode,
 				  struct fiemap_extent_info *fieinfo,
-				  loff_t start, loff_t len,
 				  get_block_t *get_block);
 extern int generic_block_fiemap(struct inode *inode,
-				struct fiemap_extent_info *fieinfo, u64 start,
-				u64 len, get_block_t *get_block);
+				struct fiemap_extent_info *fieinfo,
+				get_block_t *get_block);
 
 extern struct file_system_type *get_filesystem(struct file_system_type *fs);
 extern void put_filesystem(struct file_system_type *fs);
-- 
2.17.2

[PATCH 6/9] iomap: Remove length and start fields from iomap_fiemap

[Carlos Maiolino]

fiemap_extent_info now embeds start and length parameters, users of
iomap_fiemap() doesn't need to pass it individually anymore.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/gfs2/inode.c       | 4 +---
 fs/iomap.c            | 4 +++-
 fs/xfs/xfs_iops.c     | 8 ++------
 include/linux/iomap.h | 2 +-
 4 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 5e84d5963506..df31bd8ecf6f 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -2006,8 +2006,6 @@ static int gfs2_getattr(const struct path *path, struct kstat *stat,
 
 static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 {
-	u64 start = fieinfo->fi_start;
-	u64 len = fieinfo->fi_len;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_holder gh;
 	int ret;
@@ -2018,7 +2016,7 @@ static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
 	if (ret)
 		goto out;
 
-	ret = iomap_fiemap(inode, fieinfo, start, len, &gfs2_iomap_ops);
+	ret = iomap_fiemap(inode, fieinfo, &gfs2_iomap_ops);
 
 	gfs2_glock_dq_uninit(&gh);
 
diff --git a/fs/iomap.c b/fs/iomap.c
index 897c60215dd1..df1ea0a21563 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1183,9 +1183,11 @@ iomap_fiemap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 }
 
 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
-		loff_t start, loff_t len, const struct iomap_ops *ops)
+		 const struct iomap_ops *ops)
 {
 	struct fiemap_ctx ctx;
+	loff_t start = fi->fi_start;
+	loff_t len = fi->fi_len;
 	loff_t ret;
 
 	memset(&ctx, 0, sizeof(ctx));
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 1040e8346286..2b04f69c2c58 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1095,18 +1095,14 @@ xfs_vn_fiemap(
 	struct inode		  *inode,
 	struct fiemap_extent_info *fieinfo)
 {
-	u64	start = fieinfo->fi_start;
-	u64	length = fieinfo->fi_len;
 	int	error;
 
 	xfs_ilock(XFS_I(inode), XFS_IOLOCK_SHARED);
 	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
 		fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
-		error = iomap_fiemap(inode, fieinfo, start, length,
-				&xfs_xattr_iomap_ops);
+		error = iomap_fiemap(inode, fieinfo, &xfs_xattr_iomap_ops);
 	} else {
-		error = iomap_fiemap(inode, fieinfo, start, length,
-				&xfs_iomap_ops);
+		error = iomap_fiemap(inode, fieinfo, &xfs_iomap_ops);
 	}
 	xfs_iunlock(XFS_I(inode), XFS_IOLOCK_SHARED);
 
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 9a4258154b25..c2b5542694a2 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -145,7 +145,7 @@ int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
 vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf,
 			const struct iomap_ops *ops);
 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-		loff_t start, loff_t len, const struct iomap_ops *ops);
+		const struct iomap_ops *ops);
 loff_t iomap_seek_hole(struct inode *inode, loff_t offset,
 		const struct iomap_ops *ops);
 loff_t iomap_seek_data(struct inode *inode, loff_t offset,
-- 
2.17.2

[PATCH 7/9 V3] fiemap: Use a callback to fill fiemap extents

[Carlos Maiolino]

As a goal to enable fiemap infrastructure to be used by fibmap too, we need a
way to use different helpers to fill extent data, depending on its usage. One
helper to fill extent data stored in user address space (used in fiemap), and
another fo fill extent data stored in kernel address space (will be used in
fibmap).

This patch sets up the usage of a callback to be used to fill in the extents.
It transforms the current fiemap_fill_next_extent, into a simple helper to call
the callback, avoiding unneeded changes on any filesystem, and reutilizes the
original function as the callback used by FIEMAP.

V3:
	- Rebase to current linux-next
	- Fix conflict on rebase
	- Merge this patch into patch 07 from V2
	- Rename fi_extents_start to fi_cb_data

V2:
	- Now based on the rework on fiemap_extent_info (previous was
	  based on fiemap_ctx)

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/ioctl.c         | 45 ++++++++++++++++++++++++++-------------------
 include/linux/fs.h | 12 +++++++++---
 2 files changed, 35 insertions(+), 22 deletions(-)

diff --git a/fs/ioctl.c b/fs/ioctl.c
index 88b000ffebf4..acbb14a89f16 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -75,29 +75,14 @@ static int ioctl_fibmap(struct file *filp, int __user *p)
 	return error;
 }
 
-/**
- * fiemap_fill_next_extent - Fiemap helper function
- * @fieinfo:	Fiemap context passed into ->fiemap
- * @logical:	Extent logical start offset, in bytes
- * @phys:	Extent physical start offset, in bytes
- * @len:	Extent length, in bytes
- * @flags:	FIEMAP_EXTENT flags that describe this extent
- *
- * Called from file system ->fiemap callback. Will populate extent
- * info as passed in via arguments and copy to user memory. On
- * success, extent count on fieinfo is incremented.
- *
- * Returns 0 on success, -errno on error, 1 if this was the last
- * extent that will fit in user array.
- */
 #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_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
+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_extents_start;
+	struct fiemap_extent __user *dest = fieinfo->fi_cb_data;
 
 	/* only count the extents */
 	if (fieinfo->fi_extents_max == 0) {
@@ -130,6 +115,27 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
 		return 1;
 	return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
 }
+
+/**
+ * fiemap_fill_next_extent - Fiemap helper function
+ * @fieinfo:	Fiemap context passed into ->fiemap
+ * @logical:	Extent logical start offset, in bytes
+ * @phys:	Extent physical start offset, in bytes
+ * @len:	Extent length, in bytes
+ * @flags:	FIEMAP_EXTENT flags that describe this extent
+ *
+ * Called from file system ->fiemap callback. Will populate extent
+ * info as passed in via arguments and copy to user memory. On
+ * success, extent count on fieinfo is incremented.
+ *
+ * Returns 0 on success, -errno on error, 1 if this was the last
+ * extent that will fit in user array.
+ */
+int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
+			    u64 phys, u64 len, u32 flags)
+{
+	return fieinfo->fi_cb(fieinfo, logical, phys, len, flags);
+}
 EXPORT_SYMBOL(fiemap_fill_next_extent);
 
 /**
@@ -207,12 +213,13 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
 
 	fieinfo.fi_flags = fiemap.fm_flags;
 	fieinfo.fi_extents_max = fiemap.fm_extent_count;
-	fieinfo.fi_extents_start = ufiemap->fm_extents;
+	fieinfo.fi_cb_data = ufiemap->fm_extents;
 	fieinfo.fi_start = fiemap.fm_start;
 	fieinfo.fi_len = len;
+	fieinfo.fi_cb = fiemap_fill_user_extent;
 
 	if (fiemap.fm_extent_count != 0 &&
-	    !access_ok(fieinfo.fi_extents_start,
+	    !access_ok(fieinfo.fi_cb_data,
 		       fieinfo.fi_extents_max * sizeof(struct fiemap_extent)))
 		return -EFAULT;
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 93152b3d14bf..bed301c3c1a2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -64,6 +64,7 @@ struct fscrypt_info;
 struct fscrypt_operations;
 struct fs_context;
 struct fs_parameter_description;
+struct fiemap_extent_info;
 
 extern void __init inode_init(void);
 extern void __init inode_init_early(void);
@@ -1693,16 +1694,21 @@ extern bool may_open_dev(const struct path *path);
 /*
  * VFS FS_IOC_FIEMAP helper definitions.
  */
+
+typedef int (*fiemap_fill_cb)(struct fiemap_extent_info *fieinfo, u64 logical,
+			      u64 phys, u64 len, u32 flags);
+
 struct fiemap_extent_info {
 	unsigned int	fi_flags;		/* Flags as passed from user */
 	u64		fi_start;
 	u64		fi_len;
 	unsigned int	fi_extents_mapped;	/* Number of mapped extents */
 	unsigned int	fi_extents_max;		/* Size of fiemap_extent array */
-	struct		fiemap_extent __user *fi_extents_start;	/* Start of
-								   fiemap_extent
-								   array */
+	void		*fi_cb_data;		/* Start of fiemap_extent
+						   array */
+	fiemap_fill_cb	fi_cb;
 };
+
 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);
-- 
2.17.2

[PATCH RFC 8/9] Use FIEMAP for FIBMAP calls

[Carlos Maiolino]

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.

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

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---

I'm flagging this patch as RFC, because here lies the big discussion about how
to prevent filesystems without FIBMAP support, to keep not supporting it once
this patchset is integrated.

Christoph suggested the use of a flag, so, the main difference between this RFC
V3 and the previous one, is the inclusion of the flag FIEMAP_KERNEL_FIBMAP,
which let the underlying filesystem know if the call is coming from which ioctl
the call is coming from (fibmap or fiemap).

Note that I didn't bother to look too deep if some filesystems like ocfs2, f2fs,
etc, (filesystems I don't use to work on) does require extra checks than those I
added to this patch. The goal of this patch is to discuss the generic
implementation of FIEMAP_KERNEL_FIBMAP flag. If this implementation is ok, I'll
work on the filesystems specifically.

Note the bmap call is able to handle errors now, so, invalid fibmap requests
can now return -EINVAL instead of 0.

I added modifications to specific filesystems in this patch, otherwise there
would be a gap between the implementation of the feature (fibmap via fiemap)
where filesystems without FIBMAP support, would suddenly start to support it

The remaining of the patches in this patchset are either a copy from the
previous series (with the respective Reviewed-by tags), and/or a new updated
version containing the changes suggested previously.

Comments are much appreciated.

Cheers

 fs/ext4/extents.c     |  7 +++-
 fs/f2fs/data.c        |  5 ++-
 fs/inode.c            | 80 +++++++++++++++++++++++++++++++++++++++++--
 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 +++
 8 files changed, 133 insertions(+), 18 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index c1fed5b286df..cbfbd9d85648 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5008,7 +5008,9 @@ 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)
@@ -5055,6 +5057,9 @@ 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;
+
 		error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
 						start, len);
 
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 450f2b260c46..28e4f28d3d39 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1405,6 +1405,9 @@ 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;
@@ -1422,7 +1425,7 @@ 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;
 
diff --git a/fs/inode.c b/fs/inode.c
index db681d310465..323dfe3d26fd 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1578,6 +1578,78 @@ 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
@@ -1594,10 +1666,14 @@ 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);
+	else 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 acbb14a89f16..cbd083896518 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -75,11 +75,8 @@ 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;
@@ -87,17 +84,17 @@ 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));
@@ -113,7 +110,11 @@ 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;
 }
 
 /**
@@ -149,13 +150,23 @@ 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;
@@ -206,6 +217,10 @@ 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)
@@ -316,7 +331,8 @@ 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 df1ea0a21563..f57c50974fa3 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1194,7 +1194,7 @@ 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 2b04f69c2c58..7e2d88b4a25e 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1096,6 +1096,11 @@ xfs_vn_fiemap(
 	struct fiemap_extent_info *fieinfo)
 {
 	int	error;
+	struct	xfs_inode	*ip = XFS_I(inode);
+
+	if (fieinfo->fi_flags & FIEMAP_KERNEL_FIBMAP)
+		if (xfs_is_reflink_inode(ip) || XFS_IS_REALTIME_INODE(ip))
+			return -EINVAL;
 
 	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 bed301c3c1a2..447f992391d4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1698,6 +1698,10 @@ 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;
-- 
2.17.2

[PATCH 9/9 V2] xfs: Get rid of ->bmap

[Carlos Maiolino]

We don't need ->bmap anymore, only usage for it was FIBMAP, which is now
gone.

Also kill iomap_bmap() and iomap_bmap_actor once it has no users anymore.

V2:
	- Kill iomap_bmap() and iomap_bmap_actor()

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/iomap.c         | 34 ----------------------------------
 fs/xfs/xfs_aops.c  | 24 ------------------------
 fs/xfs/xfs_trace.h |  1 -
 3 files changed, 59 deletions(-)

diff --git a/fs/iomap.c b/fs/iomap.c
index f57c50974fa3..890751a17809 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -2138,37 +2138,3 @@ int iomap_swapfile_activate(struct swap_info_struct *sis,
 }
 EXPORT_SYMBOL_GPL(iomap_swapfile_activate);
 #endif /* CONFIG_SWAP */
-
-static loff_t
-iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
-		void *data, struct iomap *iomap)
-{
-	sector_t *bno = data, addr;
-
-	if (iomap->type == IOMAP_MAPPED) {
-		addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
-		if (addr > INT_MAX)
-			WARN(1, "would truncate bmap result\n");
-		else
-			*bno = addr;
-	}
-	return 0;
-}
-
-/* legacy ->bmap interface.  0 is the error return (!) */
-sector_t
-iomap_bmap(struct address_space *mapping, sector_t bno,
-		const struct iomap_ops *ops)
-{
-	struct inode *inode = mapping->host;
-	loff_t pos = bno << inode->i_blkbits;
-	unsigned blocksize = i_blocksize(inode);
-
-	if (filemap_write_and_wait(mapping))
-		return 0;
-
-	bno = 0;
-	iomap_apply(inode, pos, blocksize, 0, ops, &bno, iomap_bmap_actor);
-	return bno;
-}
-EXPORT_SYMBOL_GPL(iomap_bmap);
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 338b9d9984e0..26f5bb80d007 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -963,29 +963,6 @@ xfs_vm_releasepage(
 	return iomap_releasepage(page, gfp_mask);
 }
 
-STATIC sector_t
-xfs_vm_bmap(
-	struct address_space	*mapping,
-	sector_t		block)
-{
-	struct xfs_inode	*ip = XFS_I(mapping->host);
-
-	trace_xfs_vm_bmap(ip);
-
-	/*
-	 * The swap code (ab-)uses ->bmap to get a block mapping and then
-	 * bypasses the file system for actual I/O.  We really can't allow
-	 * that on reflinks inodes, so we have to skip out here.  And yes,
-	 * 0 is the magic code for a bmap error.
-	 *
-	 * Since we don't pass back blockdev info, we can't return bmap
-	 * information for rt files either.
-	 */
-	if (xfs_is_reflink_inode(ip) || XFS_IS_REALTIME_INODE(ip))
-		return 0;
-	return iomap_bmap(mapping, block, &xfs_iomap_ops);
-}
-
 STATIC int
 xfs_vm_readpage(
 	struct file		*unused,
@@ -1024,7 +1001,6 @@ const struct address_space_operations xfs_address_space_operations = {
 	.set_page_dirty		= iomap_set_page_dirty,
 	.releasepage		= xfs_vm_releasepage,
 	.invalidatepage		= xfs_vm_invalidatepage,
-	.bmap			= xfs_vm_bmap,
 	.direct_IO		= noop_direct_IO,
 	.migratepage		= iomap_migrate_page,
 	.is_partially_uptodate  = iomap_is_partially_uptodate,
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 6fcc893dfc91..aac92f2e9cdc 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -621,7 +621,6 @@ DEFINE_INODE_EVENT(xfs_readdir);
 #ifdef CONFIG_XFS_POSIX_ACL
 DEFINE_INODE_EVENT(xfs_get_acl);
 #endif
-DEFINE_INODE_EVENT(xfs_vm_bmap);
 DEFINE_INODE_EVENT(xfs_file_ioctl);
 DEFINE_INODE_EVENT(xfs_file_compat_ioctl);
 DEFINE_INODE_EVENT(xfs_ioctl_setattr);
-- 
2.17.2

Re: [PATCH RFC 8/9] Use FIEMAP for FIBMAP calls

[Andreas Dilger]

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On Feb 18, 2019, at 5:03 AM, Carlos Maiolino <cmaiolino@redhat.com> 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.
> 
> 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
> 
> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
> ---
> 
> I'm flagging this patch as RFC, because here lies the big discussion about how
> to prevent filesystems without FIBMAP support, to keep not supporting it once
> this patchset is integrated.
> 
> Christoph suggested the use of a flag, so, the main difference between this RFC
> V3 and the previous one, is the inclusion of the flag FIEMAP_KERNEL_FIBMAP,
> which let the underlying filesystem know if the call is coming from which ioctl
> the call is coming from (fibmap or fiemap).
> 
> Note that I didn't bother to look too deep if some filesystems like ocfs2, f2fs,
> etc, (filesystems I don't use to work on) does require extra checks than those I
> added to this patch. The goal of this patch is to discuss the generic
> implementation of FIEMAP_KERNEL_FIBMAP flag. If this implementation is ok, I'll
> work on the filesystems specifically.
> 
> Note the bmap call is able to handle errors now, so, invalid fibmap requests
> can now return -EINVAL instead of 0.
> 
> I added modifications to specific filesystems in this patch, otherwise there
> would be a gap between the implementation of the feature (fibmap via fiemap)
> where filesystems without FIBMAP support, would suddenly start to support it
> 
> The remaining of the patches in this patchset are either a copy from the
> previous series (with the respective Reviewed-by tags), and/or a new updated
> version containing the changes suggested previously.
> 
> Comments are much appreciated.
> 
> Cheers

Looks pretty reasonable.  A few minor nits, but nothing serious.

> diff --git a/fs/inode.c b/fs/inode.c
> index db681d310465..323dfe3d26fd 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> 
> +static int fiemap_fill_kernel_extent(struct fiemap_extent_info *fieinfo,
> +			u64 logical, u64 phys, u64 len, u32 flags)
> +{
> +
> +out:
> +	if (flags & FIEMAP_EXTENT_LAST)
> +		return 1;
> +	return 0;

Why not just the straight return:

        return !!(flags & FIEMAP_EXTENT_LAST);

or if this function is only returning 0 or 1 then it could return bool and be:

        return flags & FIEMAP_EXTENT_LAST;

> @@ -1594,10 +1666,14 @@ 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);
> +	else if (inode->i_mapping->a_ops->bmap)
> +		*block = inode->i_mapping->a_ops->bmap(inode->i_mapping,
> +						       *block);

Typically there is no "else" after return.

> @@ -113,7 +110,11 @@ 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;
> }

As above, the simpler code would be:

        return !!(flags & FIEMAP_EXTENT_LAST);

Cheers, Andreas






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Re: [PATCH RFC 8/9] Use FIEMAP for FIBMAP calls

[Carlos Maiolino]

> > Comments are much appreciated.
> > 
> > Cheers
> 
> Looks pretty reasonable.  A few minor nits, but nothing serious.

Thanks for the review...

> 
> > diff --git a/fs/inode.c b/fs/inode.c
> > index db681d310465..323dfe3d26fd 100644
> > --- a/fs/inode.c
> > +++ b/fs/inode.c
> > 
> > +static int fiemap_fill_kernel_extent(struct fiemap_extent_info *fieinfo,
> > +			u64 logical, u64 phys, u64 len, u32 flags)
> > +{
> > +
> > +out:
> > +	if (flags & FIEMAP_EXTENT_LAST)
> > +		return 1;
> > +	return 0;
> 
> Why not just the straight return:
> 
>         return !!(flags & FIEMAP_EXTENT_LAST);
> 
> or if this function is only returning 0 or 1 then it could return bool and be:
> 
>         return flags & FIEMAP_EXTENT_LAST;

Christoph asked to leave it on the good if () style :P

> 
> > @@ -1594,10 +1666,14 @@ 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);
> > +	else if (inode->i_mapping->a_ops->bmap)
> > +		*block = inode->i_mapping->a_ops->bmap(inode->i_mapping,
> > +						       *block);
> 
> Typically there is no "else" after return.

Makes sense.

> 
> > @@ -113,7 +110,11 @@ 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;
> > }
> 
> As above, the simpler code would be:
> 
>         return !!(flags & FIEMAP_EXTENT_LAST);

Same here, discussed on the last thread (I guess)

> 
> Cheers, Andreas

Thanks again for the review



-- 
Carlos

[PATCH 3/9] ecryptfs: drop direct calls to ->bmap

[Carlos Maiolino]

Replace direct ->bmap calls by bmap() method.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/ecryptfs/mmap.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index cffa0c1ec829..019572c6b39a 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -524,16 +524,12 @@ static int ecryptfs_write_end(struct file *file,
 
 static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
 {
-	int rc = 0;
-	struct inode *inode;
-	struct inode *lower_inode;
-
-	inode = (struct inode *)mapping->host;
-	lower_inode = ecryptfs_inode_to_lower(inode);
-	if (lower_inode->i_mapping->a_ops->bmap)
-		rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping,
-							 block);
-	return rc;
+	struct inode *lower_inode = ecryptfs_inode_to_lower(mapping->host);
+	int ret = bmap(lower_inode, &block);
+
+	if (ret)
+		return 0;
+	return block;
 }
 
 const struct address_space_operations ecryptfs_aops = {
-- 
2.20.1

Re: [PATCH 3/9] ecryptfs: drop direct calls to ->bmap

[kbuild test robot]

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Hi Carlos,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[cannot apply to v5.3-rc3 next-20190808]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Carlos-Maiolino/New-fiemap-infrastructure-and-bmap-removal/20190808-221354
config: x86_64-randconfig-g004-201931 (attached as .config)
compiler: gcc-7 (Debian 7.4.0-10) 7.4.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   fs/ecryptfs/mmap.c: In function 'ecryptfs_bmap':
>> fs/ecryptfs/mmap.c:528:12: error: implicit declaration of function 'bmap'; did you mean 'kmap'? [-Werror=implicit-function-declaration]
     int ret = bmap(lower_inode, &block);
               ^~~~
               kmap
   cc1: some warnings being treated as errors

vim +528 fs/ecryptfs/mmap.c

   524	
   525	static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
   526	{
   527		struct inode *lower_inode = ecryptfs_inode_to_lower(mapping->host);
 > 528		int ret = bmap(lower_inode, &block);
   529	
   530		if (ret)
   531			return 0;
   532		return block;
   533	}
   534	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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[PATCH 3/9] ecryptfs: drop direct calls to ->bmap

[Carlos Maiolino]

Replace direct ->bmap calls by bmap() method.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---

 fs/ecryptfs/mmap.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index cffa0c1ec829..019572c6b39a 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -524,16 +524,12 @@ static int ecryptfs_write_end(struct file *file,
 
 static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
 {
-	int rc = 0;
-	struct inode *inode;
-	struct inode *lower_inode;
-
-	inode = (struct inode *)mapping->host;
-	lower_inode = ecryptfs_inode_to_lower(inode);
-	if (lower_inode->i_mapping->a_ops->bmap)
-		rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping,
-							 block);
-	return rc;
+	struct inode *lower_inode = ecryptfs_inode_to_lower(mapping->host);
+	int ret = bmap(lower_inode, &block);
+
+	if (ret)
+		return 0;
+	return block;
 }
 
 const struct address_space_operations ecryptfs_aops = {
-- 
2.20.1

[PATCH 3/9] ecryptfs: drop direct calls to ->bmap

[Carlos Maiolino]

Replace direct ->bmap calls by bmap() method.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/ecryptfs/mmap.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index cdf358b209d9..ff323dccef36 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -538,16 +538,12 @@ static int ecryptfs_write_end(struct file *file,
 
 static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
 {
-	int rc = 0;
-	struct inode *inode;
-	struct inode *lower_inode;
-
-	inode = (struct inode *)mapping->host;
-	lower_inode = ecryptfs_inode_to_lower(inode);
-	if (lower_inode->i_mapping->a_ops->bmap)
-		rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping,
-							 block);
-	return rc;
+	struct inode *lower_inode = ecryptfs_inode_to_lower(mapping->host);
+	int ret = bmap(lower_inode, &block);
+
+	if (ret)
+		return 0;
+	return block;
 }
 
 const struct address_space_operations ecryptfs_aops = {
-- 
2.20.1