[PATCH v10 0/3] fallocate for block devices

[PATCH v10 0/3] fallocate for block devices

[Darrick J. Wong]

Hi,

This is a redesign of the patch series that fixes various interface
problems with the existing "zero out this part of a block device"
code.  BLKZEROOUT2 is gone.

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.  Without this patch we still have the pagecache
coherence bug that's been in the kernel forever.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.  It also allows
the combination of PUNCH_HOLE and NO_HIDE_STALE to invoke non-zeroing
discard.

Test cases for the new block device fallocate are now in xfstests as
generic/349-351.

Comments and questions are, as always, welcome.  Patches are against
4.8-rc3.

v7: Strengthen parameter checking and fix various code issues pointed
out by Linus and Christoph.
v8: More code rearranging, rebase to 4.6-rc3, and dig into alignment
issues.
v9: Forward port to 4.7.
v10: Forward port to 4.8.  Remove the extra call to
invalidate_inode_pages2_range per Bart Van Assche's request.

--D

[PATCH v10 0/3] fallocate for block devices

[Darrick J. Wong]

Hi,

This is a redesign of the patch series that fixes various interface
problems with the existing "zero out this part of a block device"
code.  BLKZEROOUT2 is gone.

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.  Without this patch we still have the pagecache
coherence bug that's been in the kernel forever.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.  It also allows
the combination of PUNCH_HOLE and NO_HIDE_STALE to invoke non-zeroing
discard.

Test cases for the new block device fallocate are now in xfstests as
generic/349-351.

Comments and questions are, as always, welcome.  Patches are against
4.8-rc3.

v7: Strengthen parameter checking and fix various code issues pointed
out by Linus and Christoph.
v8: More code rearranging, rebase to 4.6-rc3, and dig into alignment
issues.
v9: Forward port to 4.7.
v10: Forward port to 4.8.  Remove the extra call to
invalidate_inode_pages2_range per Bart Van Assche's request.

--D

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[PATCH 1/3] block: invalidate the page cache when issuing BLKZEROOUT.

[Darrick J. Wong]

Invalidate the page cache (as a regular O_DIRECT write would do) to avoid
returning stale cache contents at a later time.

v5: Refactor the 4.4 refactoring of the ioctl code into separate functions.
Split the page invalidation and the new ioctl into separate patches.
v6: Remove the call to invalidate_inode_pages2_range since we don't need it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 block/ioctl.c |   18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)


diff --git a/block/ioctl.c b/block/ioctl.c
index ed2397f..755119c 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -225,7 +225,8 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
 		unsigned long arg)
 {
 	uint64_t range[2];
-	uint64_t start, len;
+	struct address_space *mapping;
+	uint64_t start, end, len;
 
 	if (!(mode & FMODE_WRITE))
 		return -EBADF;
@@ -235,18 +236,23 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
 
 	start = range[0];
 	len = range[1];
+	end = start + len - 1;
 
 	if (start & 511)
 		return -EINVAL;
 	if (len & 511)
 		return -EINVAL;
-	start >>= 9;
-	len >>= 9;
-
-	if (start + len > (i_size_read(bdev->bd_inode) >> 9))
+	if (end >= (uint64_t)i_size_read(bdev->bd_inode))
+		return -EINVAL;
+	if (end < start)
 		return -EINVAL;
 
-	return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false);
+	/* Invalidate the page cache, including dirty pages */
+	mapping = bdev->bd_inode->i_mapping;
+	truncate_inode_pages_range(mapping, start, end);
+
+	return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
+				    false);
 }
 
 static int put_ushort(unsigned long arg, unsigned short val)

[PATCH 1/3] block: invalidate the page cache when issuing BLKZEROOUT.

[Darrick J. Wong]

Invalidate the page cache (as a regular O_DIRECT write would do) to avoid
returning stale cache contents at a later time.

v5: Refactor the 4.4 refactoring of the ioctl code into separate functions.
Split the page invalidation and the new ioctl into separate patches.
v6: Remove the call to invalidate_inode_pages2_range since we don't need it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 block/ioctl.c |   18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)


diff --git a/block/ioctl.c b/block/ioctl.c
index ed2397f..755119c 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -225,7 +225,8 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
 		unsigned long arg)
 {
 	uint64_t range[2];
-	uint64_t start, len;
+	struct address_space *mapping;
+	uint64_t start, end, len;
 
 	if (!(mode & FMODE_WRITE))
 		return -EBADF;
@@ -235,18 +236,23 @@ static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
 
 	start = range[0];
 	len = range[1];
+	end = start + len - 1;
 
 	if (start & 511)
 		return -EINVAL;
 	if (len & 511)
 		return -EINVAL;
-	start >>= 9;
-	len >>= 9;
-
-	if (start + len > (i_size_read(bdev->bd_inode) >> 9))
+	if (end >= (uint64_t)i_size_read(bdev->bd_inode))
+		return -EINVAL;
+	if (end < start)
 		return -EINVAL;
 
-	return blkdev_issue_zeroout(bdev, start, len, GFP_KERNEL, false);
+	/* Invalidate the page cache, including dirty pages */
+	mapping = bdev->bd_inode->i_mapping;
+	truncate_inode_pages_range(mapping, start, end);
+
+	return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
+				    false);
 }
 
 static int put_ushort(unsigned long arg, unsigned short val)

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[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 083e56f..46fe924 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -31,6 +31,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int granularity;
 	enum req_op op;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -50,6 +51,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		op = REQ_OP_DISCARD;
 	}
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -150,10 +155,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -202,6 +212,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 083e56f..46fe924 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -31,6 +31,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int granularity;
 	enum req_op op;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -50,6 +51,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		op = REQ_OP_DISCARD;
 	}
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -150,10 +155,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -202,6 +212,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),

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[PATCH 3/3] block: implement (some of) fallocate for block devices

[Darrick J. Wong]

After much discussion, it seems that the fallocate feature flag
FALLOC_FL_ZERO_RANGE maps nicely to SCSI WRITE SAME; and the feature
FALLOC_FL_PUNCH_HOLE maps nicely to the devices that have been
whitelisted for zeroing SCSI UNMAP.  Punch still requires that
FALLOC_FL_KEEP_SIZE is set.  A length that goes past the end of the
device will be clamped to the device size if KEEP_SIZE is set; or will
return -EINVAL if not.  Both start and length must be aligned to the
device's logical block size.

Since the semantics of fallocate are fairly well established already,
wire up the two pieces.  The other fallocate variants (collapse range,
insert range, and allocate blocks) are not supported.

v2: Incorporate feedback from Christoph & Linus.  Tentatively add
a requirement that the fallocate arguments be aligned to logical block
size, and put in a few XXX comments ahead of LSF discussion.

v3: Forward port to 4.7.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/block_dev.c |   84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/open.c      |    3 +-
 2 files changed, 86 insertions(+), 1 deletion(-)


diff --git a/fs/block_dev.c b/fs/block_dev.c
index c3cdde8..4df3fc8 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -30,6 +30,7 @@
 #include <linux/cleancache.h>
 #include <linux/dax.h>
 #include <linux/badblocks.h>
+#include <linux/falloc.h>
 #include <asm/uaccess.h>
 #include "internal.h"
 
@@ -1786,6 +1787,88 @@ static const struct address_space_operations def_blk_aops = {
 	.is_dirty_writeback = buffer_check_dirty_writeback,
 };
 
+#define	BLKDEV_FALLOC_FL_SUPPORTED					\
+		(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |		\
+		 FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
+
+static long blkdev_fallocate(struct file *file, int mode, loff_t start,
+			     loff_t len)
+{
+	struct block_device *bdev = I_BDEV(bdev_file_inode(file));
+	struct request_queue *q = bdev_get_queue(bdev);
+	struct address_space *mapping;
+	loff_t end = start + len - 1;
+	loff_t isize;
+	int error;
+
+	/* Fail if we don't recognize the flags. */
+	if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)
+		return -EOPNOTSUPP;
+
+	/* Don't go off the end of the device. */
+	isize = i_size_read(bdev->bd_inode);
+	if (start >= isize)
+		return -EINVAL;
+	if (end > isize) {
+		if (mode & FALLOC_FL_KEEP_SIZE) {
+			len = isize - start;
+			end = start + len - 1;
+		} else
+			return -EINVAL;
+	}
+
+	/*
+	 * Don't allow IO that isn't aligned to logical block size.
+	 */
+	if ((start | len) & (bdev_logical_block_size(bdev) - 1))
+		return -EINVAL;
+
+	/* Invalidate the page cache, including dirty pages. */
+	mapping = bdev->bd_inode->i_mapping;
+	truncate_inode_pages_range(mapping, start, end);
+
+	switch (mode) {
+	case FALLOC_FL_ZERO_RANGE:
+	case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
+		error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
+					    GFP_KERNEL, false);
+		if (error)
+			return error;
+		break;
+	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
+		/* Only punch if the device can do zeroing discard. */
+		if (!blk_queue_discard(q) || !q->limits.discard_zeroes_data)
+			return -EOPNOTSUPP;
+		error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
+					     GFP_KERNEL, 0);
+		if (error)
+			return error;
+		break;
+	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
+		/*
+		 * XXX: a well known search engine vendor interprets this
+		 * flag (in other circumstances) to mean "I don't care if
+		 * we can read stale contents later".  Is it appropriate
+		 * to wire this up to the non-zeroing discard?
+		 */
+		error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
+					     GFP_KERNEL, 0);
+		if (error)
+			return error;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	/*
+	 * Invalidate again; if someone wandered in and dirtied a page,
+	 * the caller will be given -EBUSY;
+	 */
+	return invalidate_inode_pages2_range(mapping,
+					     start >> PAGE_SHIFT,
+					     end >> PAGE_SHIFT);
+}
+
 const struct file_operations def_blk_fops = {
 	.open		= blkdev_open,
 	.release	= blkdev_close,
@@ -1800,6 +1883,7 @@ const struct file_operations def_blk_fops = {
 #endif
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= iter_file_splice_write,
+	.fallocate	= blkdev_fallocate,
 };
 
 int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
diff --git a/fs/open.c b/fs/open.c
index 4fd6e25..01b6092 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -289,7 +289,8 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	 * Let individual file system decide if it supports preallocation
 	 * for directories or not.
 	 */
-	if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
+	if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode) &&
+	    !S_ISBLK(inode->i_mode))
 		return -ENODEV;
 
 	/* Check for wrap through zero too */

[PATCH 3/3] block: implement (some of) fallocate for block devices

[Darrick J. Wong]

After much discussion, it seems that the fallocate feature flag
FALLOC_FL_ZERO_RANGE maps nicely to SCSI WRITE SAME; and the feature
FALLOC_FL_PUNCH_HOLE maps nicely to the devices that have been
whitelisted for zeroing SCSI UNMAP.  Punch still requires that
FALLOC_FL_KEEP_SIZE is set.  A length that goes past the end of the
device will be clamped to the device size if KEEP_SIZE is set; or will
return -EINVAL if not.  Both start and length must be aligned to the
device's logical block size.

Since the semantics of fallocate are fairly well established already,
wire up the two pieces.  The other fallocate variants (collapse range,
insert range, and allocate blocks) are not supported.

v2: Incorporate feedback from Christoph & Linus.  Tentatively add
a requirement that the fallocate arguments be aligned to logical block
size, and put in a few XXX comments ahead of LSF discussion.

v3: Forward port to 4.7.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/block_dev.c |   84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/open.c      |    3 +-
 2 files changed, 86 insertions(+), 1 deletion(-)


diff --git a/fs/block_dev.c b/fs/block_dev.c
index c3cdde8..4df3fc8 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -30,6 +30,7 @@
 #include <linux/cleancache.h>
 #include <linux/dax.h>
 #include <linux/badblocks.h>
+#include <linux/falloc.h>
 #include <asm/uaccess.h>
 #include "internal.h"
 
@@ -1786,6 +1787,88 @@ static const struct address_space_operations def_blk_aops = {
 	.is_dirty_writeback = buffer_check_dirty_writeback,
 };
 
+#define	BLKDEV_FALLOC_FL_SUPPORTED					\
+		(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |		\
+		 FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
+
+static long blkdev_fallocate(struct file *file, int mode, loff_t start,
+			     loff_t len)
+{
+	struct block_device *bdev = I_BDEV(bdev_file_inode(file));
+	struct request_queue *q = bdev_get_queue(bdev);
+	struct address_space *mapping;
+	loff_t end = start + len - 1;
+	loff_t isize;
+	int error;
+
+	/* Fail if we don't recognize the flags. */
+	if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)
+		return -EOPNOTSUPP;
+
+	/* Don't go off the end of the device. */
+	isize = i_size_read(bdev->bd_inode);
+	if (start >= isize)
+		return -EINVAL;
+	if (end > isize) {
+		if (mode & FALLOC_FL_KEEP_SIZE) {
+			len = isize - start;
+			end = start + len - 1;
+		} else
+			return -EINVAL;
+	}
+
+	/*
+	 * Don't allow IO that isn't aligned to logical block size.
+	 */
+	if ((start | len) & (bdev_logical_block_size(bdev) - 1))
+		return -EINVAL;
+
+	/* Invalidate the page cache, including dirty pages. */
+	mapping = bdev->bd_inode->i_mapping;
+	truncate_inode_pages_range(mapping, start, end);
+
+	switch (mode) {
+	case FALLOC_FL_ZERO_RANGE:
+	case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
+		error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
+					    GFP_KERNEL, false);
+		if (error)
+			return error;
+		break;
+	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
+		/* Only punch if the device can do zeroing discard. */
+		if (!blk_queue_discard(q) || !q->limits.discard_zeroes_data)
+			return -EOPNOTSUPP;
+		error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
+					     GFP_KERNEL, 0);
+		if (error)
+			return error;
+		break;
+	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
+		/*
+		 * XXX: a well known search engine vendor interprets this
+		 * flag (in other circumstances) to mean "I don't care if
+		 * we can read stale contents later".  Is it appropriate
+		 * to wire this up to the non-zeroing discard?
+		 */
+		error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
+					     GFP_KERNEL, 0);
+		if (error)
+			return error;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	/*
+	 * Invalidate again; if someone wandered in and dirtied a page,
+	 * the caller will be given -EBUSY;
+	 */
+	return invalidate_inode_pages2_range(mapping,
+					     start >> PAGE_SHIFT,
+					     end >> PAGE_SHIFT);
+}
+
 const struct file_operations def_blk_fops = {
 	.open		= blkdev_open,
 	.release	= blkdev_close,
@@ -1800,6 +1883,7 @@ const struct file_operations def_blk_fops = {
 #endif
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= iter_file_splice_write,
+	.fallocate	= blkdev_fallocate,
 };
 
 int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
diff --git a/fs/open.c b/fs/open.c
index 4fd6e25..01b6092 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -289,7 +289,8 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	 * Let individual file system decide if it supports preallocation
 	 * for directories or not.
 	 */
-	if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
+	if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode) &&
+	    !S_ISBLK(inode->i_mode))
 		return -ENODEV;
 
 	/* Check for wrap through zero too */

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Re: [PATCH v10 0/3] fallocate for block devices

[Martin K. Petersen]

>>>>> "Darrick" == Darrick J Wong <darrick.wong@oracle.com> writes:

Darrick,

Darrick> This is a redesign of the patch series that fixes various
Darrick> interface problems with the existing "zero out this part of a
Darrick> block device" code.  BLKZEROOUT2 is gone.

Looks good to me. Let's get this merged. Pretty please!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH v10 0/3] fallocate for block devices

[Martin K. Petersen]

>>>>> "Darrick" == Darrick J Wong <darrick.wong@oracle.com> writes:

Darrick,

Darrick> This is a redesign of the patch series that fixes various
Darrick> interface problems with the existing "zero out this part of a
Darrick> block device" code.  BLKZEROOUT2 is gone.

Looks good to me. Let's get this merged. Pretty please!

-- 
Martin K. Petersen	Oracle Linux Engineering

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[PATCH v11 0/3] fallocate for block devices

[Darrick J. Wong]

Hi Andrew & others,

This is a resend of the patchset to fix page cache coherency with
BLKZEROOUT and implement fallocate for block devices.  This time I'm
sending it direct to Andrew for inclusion because the block layer
maintainer has not been responsive over the past year of submissions.
Can this please go upstream for 4.9?

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.  Without this patch we still have the pagecache
coherence bug that's been in the kernel forever.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.  It also allows
the combination of PUNCH_HOLE and NO_HIDE_STALE to invoke non-zeroing
discard.

Test cases for the new block device fallocate are now in xfstests as
generic/349-351.

Comments and questions are, as always, welcome.  Patches are against
4.8-rc8.

v7: Strengthen parameter checking and fix various code issues pointed
out by Linus and Christoph.
v8: More code rearranging, rebase to 4.6-rc3, and dig into alignment
issues.
v9: Forward port to 4.7.
v10: Forward port to 4.8.  Remove the extra call to
invalidate_inode_pages2_range per Bart Van Assche's request.
v11: Minor fallocate code cleanups suggested by Bart Van Assche.

--D

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 083e56f..46fe924 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -31,6 +31,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int granularity;
 	enum req_op op;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -50,6 +51,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		op = REQ_OP_DISCARD;
 	}
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -150,10 +155,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -202,6 +212,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 083e56f..46fe924 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -31,6 +31,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int granularity;
 	enum req_op op;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -50,6 +51,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		op = REQ_OP_DISCARD;
 	}
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -150,10 +155,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -202,6 +212,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),

_______________________________________________
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http://oss.sgi.com/mailman/listinfo/xfs

[PATCH v10 0/3] fallocate for block devices

[Darrick J. Wong]

Hi Andrew & others,

This is a resend of the patchset to fix page cache coherency with
BLKZEROOUT and implement fallocate for block devices.  This time I'm
sending it direct to Andrew for inclusion because the block layer
maintainer has not been responsive over the past year of submissions.
Can this please go upstream for 4.9?

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.  Without this patch we still have the pagecache
coherence bug that's been in the kernel forever.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.  It also allows
the combination of PUNCH_HOLE and NO_HIDE_STALE to invoke non-zeroing
discard.

Test cases for the new block device fallocate are now in xfstests as
generic/349-351.

Comments and questions are, as always, welcome.  Patches are against
4.8-rc8.

v7: Strengthen parameter checking and fix various code issues pointed
out by Linus and Christoph.
v8: More code rearranging, rebase to 4.6-rc3, and dig into alignment
issues.
v9: Forward port to 4.7.
v10: Forward port to 4.8.  Remove the extra call to
invalidate_inode_pages2_range per Bart Van Assche's request.

--D

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 083e56f..46fe924 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -31,6 +31,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int granularity;
 	enum req_op op;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -50,6 +51,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		op = REQ_OP_DISCARD;
 	}
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -150,10 +155,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -202,6 +212,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 083e56f..46fe924 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -31,6 +31,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int granularity;
 	enum req_op op;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -50,6 +51,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		op = REQ_OP_DISCARD;
 	}
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -150,10 +155,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -202,6 +212,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),

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Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Hannes Reinecke]

On 09/29/2016 02:39 AM, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
> ---
>  block/blk-lib.c |   15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)

Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Hannes Reinecke]

On 09/29/2016 02:39 AM, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> Reviewed-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
> Reviewed-by: Martin K. Petersen <martin.petersen-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> ---
>  block/blk-lib.c |   15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
Reviewed-by: Hannes Reinecke <hare-IBi9RG/b67k@public.gmane.org>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare-l3A5Bk7waGM@public.gmane.org			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)

Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Hannes Reinecke]

On 09/29/2016 02:39 AM, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
> ---
>  block/blk-lib.c |   15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)

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http://oss.sgi.com/mailman/listinfo/xfs

[PATCH v9 0/3] fallocate for block devices

[Darrick J. Wong]

Hi,

This is a redesign of the patch series that fixes various interface
problems with the existing "zero out this part of a block device"
code.  BLKZEROOUT2 is gone.

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.  Without this patch we still have the pagecache
coherence bug that's been in the kernel forever.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.  It also allows
the combination of PUNCH_HOLE and NO_HIDE_STALE to invoke non-zeroing
discard.

Test cases for the new block device fallocate are now in xfstests as
generic/349-351.

Comments and questions are, as always, welcome.  Patches are against
4.7-rc3.

v7: Strengthen parameter checking and fix various code issues pointed
out by Linus and Christoph.
v8: More code rearranging, rebase to 4.6-rc3, and dig into alignment
issues.
v9: Forward port to 4.7.

--D

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9e29dc3..012aa98 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -29,6 +29,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	struct bio *bio = *biop;
 	unsigned int granularity;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -37,6 +38,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	if ((type & REQ_SECURE) && !blk_queue_secdiscard(q))
 		return -EOPNOTSUPP;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -140,10 +145,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -191,6 +201,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, WRITE,

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9e29dc3..012aa98 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -29,6 +29,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	struct bio *bio = *biop;
 	unsigned int granularity;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -37,6 +38,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	if ((type & REQ_SECURE) && !blk_queue_secdiscard(q))
 		return -EOPNOTSUPP;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -140,10 +145,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -191,6 +201,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, WRITE,

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9e29dc3..012aa98 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -29,6 +29,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	struct bio *bio = *biop;
 	unsigned int granularity;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -37,6 +38,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	if ((type & REQ_SECURE) && !blk_queue_secdiscard(q))
 		return -EOPNOTSUPP;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -140,10 +145,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -191,6 +201,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, WRITE,

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Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Bart Van Assche]

On 06/17/2016 03:19 AM, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>

Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Bart Van Assche]

On 06/17/2016 03:19 AM, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>

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Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Martin K. Petersen]

>>>>> "Darrick" == Darrick J Wong <darrick.wong@oracle.com> writes:

Darrick> Make sure that the offset and length arguments that we're using
Darrick> to construct WRITE SAME and DISCARD requests are actually
Darrick> aligned to the logical block size.  Failure to do this causes
Darrick> other errors in other parts of the block layer or the SCSI
Darrick> layer because disks don't support partial logical block writes.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Martin K. Petersen]

>>>>> "Darrick" == Darrick J Wong <darrick.wong@oracle.com> writes:

Darrick> Make sure that the offset and length arguments that we're using
Darrick> to construct WRITE SAME and DISCARD requests are actually
Darrick> aligned to the logical block size.  Failure to do this causes
Darrick> other errors in other parts of the block layer or the SCSI
Darrick> layer because disks don't support partial logical block writes.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

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[RFC DONOTMERGE v8 0/3] fallocate for block devices

[Darrick J. Wong]

Hi,

This is a redesign of the patch series that fixes various interface
problems with the existing "zero out this part of a block device"
code.  BLKZEROOUT2 is gone.

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.  It also allows
the combination of PUNCH_HOLE and NO_HIDE_STALE to invoke non-zeroing
discard.

The point of this patchset is not to go upstream, but is to be a
starting point for a discussion at LSF.  Don't merge this!  Foremost
in my mind is whether or not we require the offset/len parameters to
be aligned to logical block size or minimum_io_size; what error code
to return for unaligned values; and whether or not we should allow
byte ranges and zero blocks with the page cache (like file fallocate
does now).  It'll also be a jumping off point for Brian Foster and
Mike Snitzer's patches to allow bdev clients to ask that space be
allocated to a range, and to plumb that out to userspace.

Test cases for the new block device fallocate have been submitted to
the xfstests list as generic/70[5-7], though the latest versions of
those test cases will be attached to this patchset for convenience.

Comments and questions are, as always, welcome.  Patches are against
4.6-rc3.

v7: Strengthen parameter checking and fix various code issues pointed
out by Linus and Christoph.
v8: More code rearranging, rebase to 4.6-rc3, and dig into alignment
issues.

--D

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9ebf653..9dca6bb 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -49,6 +49,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	struct bio *bio;
 	int ret = 0;
 	struct blk_plug plug;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -56,6 +57,10 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -148,6 +153,7 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q = bdev_get_queue(bdev);
 	unsigned int max_write_same_sectors;
+	sector_t bs_mask;
 	struct bio_batch bb;
 	struct bio *bio;
 	int ret = 0;
@@ -155,6 +161,10 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -218,9 +228,14 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio;
 	struct bio_batch bb;
+	sector_t bs_mask;
 	unsigned int sz;
 	DECLARE_COMPLETION_ONSTACK(wait);
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	atomic_set(&bb.done, 1);
 	bb.error = 0;
 	bb.wait = &wait;

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9ebf653..9dca6bb 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -49,6 +49,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	struct bio *bio;
 	int ret = 0;
 	struct blk_plug plug;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -56,6 +57,10 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -148,6 +153,7 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q = bdev_get_queue(bdev);
 	unsigned int max_write_same_sectors;
+	sector_t bs_mask;
 	struct bio_batch bb;
 	struct bio *bio;
 	int ret = 0;
@@ -155,6 +161,10 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -218,9 +228,14 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio;
 	struct bio_batch bb;
+	sector_t bs_mask;
 	unsigned int sz;
 	DECLARE_COMPLETION_ONSTACK(wait);
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	atomic_set(&bb.done, 1);
 	bb.error = 0;
 	bb.wait = &wait;

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Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Christoph Hellwig]

On Tue, Apr 12, 2016 at 09:01:35PM -0700, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.

FYI, Bart has just been posting a patchset in that includes this, but
goes further.  Can you take a look at it?

Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Christoph Hellwig]

On Tue, Apr 12, 2016 at 09:01:35PM -0700, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.

FYI, Bart has just been posting a patchset in that includes this, but
goes further.  Can you take a look at it?

_______________________________________________
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xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH v7 0/3] fallocate for block devices to provide zero-out

[Darrick J. Wong]

Hi,

This is a redesign of the patch series that fixes various interface
problems with the existing "zero out this part of a block device"
code.  BLKZEROOUT2 is gone.

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.

Test cases for the new block device fallocate have been submitted to
the xfstests list as generic/70[5-7], though the numbering will change
to a lower number when the API and the tests are accepted upstream.
Look for the v2 testcase patch, which reflects v7 of this patchset.

Comments and questions are, as always, welcome.  Patches are against
4.5.

v7: Strengthen parameter checking and fix various code issues pointed
out by Linus and Christoph.

--D

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9ebf653..9dca6bb 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -49,6 +49,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	struct bio *bio;
 	int ret = 0;
 	struct blk_plug plug;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -56,6 +57,10 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -148,6 +153,7 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q = bdev_get_queue(bdev);
 	unsigned int max_write_same_sectors;
+	sector_t bs_mask;
 	struct bio_batch bb;
 	struct bio *bio;
 	int ret = 0;
@@ -155,6 +161,10 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -218,9 +228,14 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio;
 	struct bio_batch bb;
+	sector_t bs_mask;
 	unsigned int sz;
 	DECLARE_COMPLETION_ONSTACK(wait);
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	atomic_set(&bb.done, 1);
 	bb.error = 0;
 	bb.wait = &wait;

[PATCH v6 0/3] fallocate for block devices to provide zero-out

[Darrick J. Wong]

Hi,

This is a redesign of the patch series that fixes various interface
problems with the existing "zero out this part of a block device"
code.  BLKZEROOUT2 is gone.

The first patch is still a fix to the existing BLKZEROOUT ioctl to
invalidate the page cache if the zeroing command to the underlying
device succeeds.

The second patch changes the internal block device functions to reject
attempts to discard or zeroout that are not aligned to the logical
block size.  Previously, we only checked that the start/len parameters
were 512-byte aligned, which caused kernel BUG_ONs for unaligned IOs
to 4k-LBA devices.

The third patch creates an fallocate handler for block devices, wires
up the FALLOC_FL_PUNCH_HOLE flag to zeroing-discard, and connects
FALLOC_FL_ZERO_RANGE to write-same so that we can have a consistent
fallocate interface between files and block devices.

Test cases[1] for the new block device fallocate will have been
submitted to the xfstests list as generic/70[5-7], though the
numbering will change to a lower number when the API and the tests are
accepted upstream.

Comments and questions are, as always, welcome.  Patches are against
4.5-rc6.

--D

[1] https://github.com/djwong/xfstests/commit/fdc0980ef01076dfb246fd1db2511227e9f67a3f

[PATCH 2/3] block: require write_same and discard requests align to logical block size

[Darrick J. Wong]

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other
parts of the block layer or the SCSI layer because disks don't support
partial logical block writes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 block/blk-lib.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)


diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9ebf653..3e5ca28 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -49,6 +49,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	struct bio *bio;
 	int ret = 0;
 	struct blk_plug plug;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -56,6 +57,10 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector & bs_mask) || ((sector + nr_sects) & bs_mask))
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -148,6 +153,7 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q = bdev_get_queue(bdev);
 	unsigned int max_write_same_sectors;
+	sector_t bs_mask;
 	struct bio_batch bb;
 	struct bio *bio;
 	int ret = 0;
@@ -155,6 +161,10 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector & bs_mask) || ((sector + nr_sects) & bs_mask))
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -218,9 +228,14 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio;
 	struct bio_batch bb;
+	sector_t bs_mask;
 	unsigned int sz;
 	DECLARE_COMPLETION_ONSTACK(wait);
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector & bs_mask) || ((sector + nr_sects) & bs_mask))
+		return -EINVAL;
+
 	atomic_set(&bb.done, 1);
 	bb.error = 0;
 	bb.wait = &wait;

Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Linus Torvalds]

On Fri, Mar 4, 2016 at 4:56 PM, Darrick J. Wong <darrick.wong@oracle.com> wrote:
>
> +       bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
> +       if ((sector & bs_mask) || ((sector + nr_sects) & bs_mask))
> +               return -EINVAL;

This test may _work_, but it's kind of crazily overly complicated.

The sane test would be just "are the start and length aligned":

        if ((sector & bs_mask) || (nr_sects & bs_mask))
                return -EINVAL;

and the *smart* test is simpler still, and asks "are there invalid
bits in either the start or the length":

        if ((sector | nr_sects) & bs_mask)
                return -EINVAL:

I suspect either of these would be fine, and the compiler may even
notice that there's the smart way of doing it.

The compiler *might* even notice that the original version can be
simplified and generate sane code.

But I think that original version is not only overly complicated, it's
also actually less obvious than the simpler versions, if only because
the whole conditional is so big that you have to actively parse it.

That last shortest form is actually so simple that I think it's the
easiest to understand too - the conditional is simply so small that it
doesn't take a lot of effort to see what it does.

            Linus

Re: [PATCH 2/3] block: require write_same and discard requests align to logical block size

[Christoph Hellwig]

On Fri, Mar 04, 2016 at 04:56:10PM -0800, Darrick J. Wong wrote:
> Make sure that the offset and length arguments that we're using to
> construct WRITE SAME and DISCARD requests are actually aligned to the
> logical block size.  Failure to do this causes other errors in other
> parts of the block layer or the SCSI layer because disks don't support
> partial logical block writes.

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>