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fs: interface for directly reading/writing compressed data

PATCH Superseded Omar Sandoval 2 participants 16 messages Jan 22, 2021 – Feb 3, 2021

Subsystems (12)

v7 of 9 Superseded Latest is v9 →

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#0 lore raw

v7 cover fs: interface for directly reading/writing compressed data

From: Omar Sandoval <[email protected]>

This series adds an API for reading compressed data on a filesystem without decompressing it as well as support for writing compressed data directly to the filesystem. As with the previous submissions, I've included a man page patch describing the API. I have test cases (including fsstress support) and example programs which I'll send up [1].

The main use-case is Btrfs send/receive: currently, when sending data from one compressed filesystem to another, the sending side decompresses the data and the receiving side recompresses it before writing it out. This is wasteful and can be avoided if we can just send and write compressed extents. The patches implementing the send/receive support will be sent shortly.

Patches 1-3 add the VFS support and UAPI. Patch 4 is a fix that this series depends on; it can be merged independently. Patches 5-8 are Btrfs prep patches. Patch 9 adds Btrfs encoded read support and patch 10 adds Btrfs encoded write support.

These patches are based on Dave Sterba's Btrfs misc-next branch [2], which is in turn currently based on v5.11-rc4.

Changes since v6 [3]:

- Dropped O_CLOEXEC requirement for O_ALLOW_ENCODED.
- Readded lost FMODE_ENCODED_IO check.
- Used macros instead of enum for ENCODED_IOV_COMPRESSION_* and ENCODED_IOV_ENCRYPTION_*.
- Moved encoded I/O definitions to their own UAPI header file.
- Fixed style nits.
- Added reviewed-bys.
- Addressed man page nits.

1: https://github.com/osandov/xfstests/tree/rwf-encoded
2: https://github.com/kdave/btrfs-devel/tree/misc-next
3: https://lore.kernel.org/linux-btrfs/[email protected]/

Omar Sandoval (10):
iov_iter: add copy_struct_from_iter()
fs: add O_ALLOW_ENCODED open flag
fs: add RWF_ENCODED for reading/writing compressed data
btrfs: fix check_data_csum() error message for direct I/O
btrfs: don't advance offset for compressed bios in
btrfs_csum_one_bio()
btrfs: add ram_bytes and offset to btrfs_ordered_extent
btrfs: support different disk extent size for delalloc
btrfs: optionally extend i_size in cow_file_range_inline()
btrfs: implement RWF_ENCODED reads
btrfs: implement RWF_ENCODED writes

 Documentation/filesystems/encoded_io.rst |  74 ++
 Documentation/filesystems/index.rst      |   1 +
 arch/alpha/include/uapi/asm/fcntl.h      |   1 +
 arch/parisc/include/uapi/asm/fcntl.h     |   1 +
 arch/sparc/include/uapi/asm/fcntl.h      |   1 +
 fs/btrfs/compression.c                   |  12 +-
 fs/btrfs/compression.h                   |   6 +-
 fs/btrfs/ctree.h                         |   9 +-
 fs/btrfs/delalloc-space.c                |  18 +-
 fs/btrfs/file-item.c                     |  35 +-
 fs/btrfs/file.c                          |  46 +-
 fs/btrfs/inode.c                         | 936 ++++++++++++++++++++---
 fs/btrfs/ordered-data.c                  |  80 +-
 fs/btrfs/ordered-data.h                  |  18 +-
 fs/btrfs/relocation.c                    |   4 +-
 fs/fcntl.c                               |  10 +-
 fs/namei.c                               |   4 +
 fs/read_write.c                          | 168 +++-
 include/linux/encoded_io.h               |  17 +
 include/linux/fcntl.h                    |   2 +-
 include/linux/fs.h                       |  13 +
 include/linux/uio.h                      |   2 +
 include/uapi/asm-generic/fcntl.h         |   4 +
 include/uapi/linux/encoded_io.h          |  30 +
 include/uapi/linux/fs.h                  |   5 +-
 lib/iov_iter.c                           |  82 ++
 26 files changed, 1378 insertions(+), 201 deletions(-)
 create mode 100644 Documentation/filesystems/encoded_io.rst
 create mode 100644 include/linux/encoded_io.h
 create mode 100644 include/uapi/linux/encoded_io.h
Signature · 1 line
2.30.0
#1 lore raw

PATCH v7 1/10 iov_iter: add copy_struct_from_iter()

From: Omar Sandoval <[email protected]>

This is essentially copy_struct_from_user() but for an iov_iter.

---
 include/linux/uio.h |  2 ++
 lib/iov_iter.c      | 82 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)
include/linux/uio.h +2 -0
index 72d88566694e..f4e6ea85a269 100644
@@ -121,6 +121,8 @@ size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
 			 struct iov_iter *i);
 size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
 			 struct iov_iter *i);
+int copy_struct_from_iter(void *dst, size_t ksize, struct iov_iter *i,
+			  size_t usize);
 
 size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
 size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
lib/iov_iter.c +82 -0

88 lines not on this page · raw message

Signature · 1 line
2.30.0
#2 lore raw

PATCH v7 2/10 fs: add O_ALLOW_ENCODED open flag

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

The upcoming RWF_ENCODED operation introduces some security concerns:

1. Compressed writes will pass arbitrary data to decompression algorithms in the kernel.
2. Compressed reads can leak truncated/hole punched data.

Therefore, we need to require privilege for RWF_ENCODED. It's not possible to do the permissions checks at the time of the read or write because, e.g., io_uring submits IO from a worker thread. So, add an open flag which requires CAP_SYS_ADMIN. It can also be set and cleared with fcntl(). The flag is not cleared in any way on fork or exec.

Note that the usual issue that unknown open flags are ignored doesn't really matter for O_ALLOW_ENCODED; if the kernel doesn't support O_ALLOW_ENCODED, then it doesn't support RWF_ENCODED, either.

---
 arch/alpha/include/uapi/asm/fcntl.h  |  1 +
 arch/parisc/include/uapi/asm/fcntl.h |  1 +
 arch/sparc/include/uapi/asm/fcntl.h  |  1 +
 fs/fcntl.c                           | 10 ++++++++--
 fs/namei.c                           |  4 ++++
 include/linux/fcntl.h                |  2 +-
 include/uapi/asm-generic/fcntl.h     |  4 ++++
 7 files changed, 20 insertions(+), 3 deletions(-)
arch/alpha/include/uapi/asm/fcntl.h +1 -0
index 50bdc8e8a271..391e0d112e41 100644
@@ -34,6 +34,7 @@
 
 #define O_PATH		040000000
 #define __O_TMPFILE	0100000000
+#define O_ALLOW_ENCODED	0200000000
 
 #define F_GETLK		7
 #define F_SETLK		8
arch/parisc/include/uapi/asm/fcntl.h +1 -0
index 03dee816cb13..72ea9bdf5f04 100644
@@ -19,6 +19,7 @@
 
 #define O_PATH		020000000
 #define __O_TMPFILE	040000000
+#define O_ALLOW_ENCODED	100000000
 
 #define F_GETLK64	8
 #define F_SETLK64	9
arch/sparc/include/uapi/asm/fcntl.h +1 -0
index 67dae75e5274..ac3e8c9cb32c 100644
@@ -37,6 +37,7 @@
 
 #define O_PATH		0x1000000
 #define __O_TMPFILE	0x2000000
+#define O_ALLOW_ENCODED	0x8000000
 
 #define F_GETOWN	5	/*  for sockets. */
 #define F_SETOWN	6	/*  for sockets. */
fs/fcntl.c +8 -2
index 05b36b28f2e8..2c1f0580a497 100644
@@ -30,7 +30,8 @@
 #include <asm/siginfo.h>
 #include <linux/uaccess.h>
 
-#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
+#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME | \
+		    O_ALLOW_ENCODED)
 
 static int setfl(int fd, struct file * filp, unsigned long arg)
 {
@@ -49,6 +50,11 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
 		if (!inode_owner_or_capable(inode))
 			return -EPERM;
 
+	/* O_ALLOW_ENCODED can only be set by superuser */
+	if ((arg & O_ALLOW_ENCODED) && !(filp->f_flags & O_ALLOW_ENCODED) &&
+	    !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
 	/* required for strict SunOS emulation */
 	if (O_NONBLOCK != O_NDELAY)
 	       if (arg & O_NDELAY)
@@ -1035,7 +1041,7 @@ static int __init fcntl_init(void)
 	 * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY
 	 * is defined as O_NONBLOCK on some platforms and not on others.
 	 */
-	BUILD_BUG_ON(21 - 1 /* for O_RDONLY being 0 */ !=
+	BUILD_BUG_ON(22 - 1 /* for O_RDONLY being 0 */ !=
 		HWEIGHT32(
 			(VALID_OPEN_FLAGS & ~(O_NONBLOCK | O_NDELAY)) |
 			__FMODE_EXEC | __FMODE_NONOTIFY));
fs/namei.c +4 -0
index 78443a85480a..73b925b133a0 100644
@@ -2892,6 +2892,10 @@ static int may_open(const struct path *path, int acc_mode, int flag)
 	if (flag & O_NOATIME && !inode_owner_or_capable(inode))
 		return -EPERM;
 
+	/* O_ALLOW_ENCODED can only be set by superuser */
+	if ((flag & O_ALLOW_ENCODED) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
 	return 0;
 }
 
include/linux/fcntl.h +1 -1
index 921e750843e6..dc66c557b7d0 100644
@@ -10,7 +10,7 @@
 	(O_RDONLY | O_WRONLY | O_RDWR | O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC | \
 	 O_APPEND | O_NDELAY | O_NONBLOCK | __O_SYNC | O_DSYNC | \
 	 FASYNC	| O_DIRECT | O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | \
-	 O_NOATIME | O_CLOEXEC | O_PATH | __O_TMPFILE)
+	 O_NOATIME | O_CLOEXEC | O_PATH | __O_TMPFILE | O_ALLOW_ENCODED)
 
 /* List of all valid flags for the how->upgrade_mask argument: */
 #define VALID_UPGRADE_FLAGS \
include/uapi/asm-generic/fcntl.h +4 -0
index 9dc0bf0c5a6e..75321c7a66ac 100644
@@ -89,6 +89,10 @@
 #define __O_TMPFILE	020000000
 #endif
 
+#ifndef O_ALLOW_ENCODED
+#define O_ALLOW_ENCODED	040000000
+#endif
+
 /* a horrid kludge trying to make sure that this will fail on old kernels */
 #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY)
 #define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT)      
Signature · 1 line
2.30.0
Reviewed-by on v7 2/10
#3 lore raw

Re: [PATCH v7 02/10] fs: add O_ALLOW_ENCODED open flag

Quoted 14 lines · Omar Sandoval

From: Omar Sandoval <[email protected]>

The upcoming RWF_ENCODED operation introduces some security concerns:

1. Compressed writes will pass arbitrary data to decompression algorithms in the kernel.
2. Compressed reads can leak truncated/hole punched data.

Therefore, we need to require privilege for RWF_ENCODED. It's not possible to do the permissions checks at the time of the read or write because, e.g., io_uring submits IO from a worker thread. So, add an open flag which requires CAP_SYS_ADMIN. It can also be set and cleared with fcntl(). The flag is not cleared in any way on fork or exec.

Quoted 5 lines

Note that the usual issue that unknown open flags are ignored doesn't really matter for O_ALLOW_ENCODED; if the kernel doesn't support O_ALLOW_ENCODED, then it doesn't support RWF_ENCODED, either.

Thanks,

Josef

#4 lore raw

PATCH v7 3/10 fs: add RWF_ENCODED for reading/writing compressed data

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

Btrfs supports transparent compression: data written by the user can be compressed when written to disk and decompressed when read back. However, we'd like to add an interface to write pre-compressed data directly to the filesystem, and the matching interface to read compressed data without decompressing it. This adds support for so-called "encoded I/O" via preadv2() and pwritev2().

A new RWF_ENCODED flags indicates that a read or write is "encoded". If this flag is set, iov[0].iov_base points to a struct encoded_iov which is used for metadata: namely, the compression algorithm, unencoded (i.e., decompressed) length, and what subrange of the unencoded data should be used (needed for truncated or hole-punched extents and when reading in the middle of an extent). For reads, the filesystem returns this information; for writes, the caller provides it to the filesystem. iov[0].iov_len must be set to sizeof(struct encoded_iov), which can be used to extend the interface in the future a la copy_struct_from_user(). The remaining iovecs contain the encoded extent.

This adds the VFS helpers for supporting encoded I/O and documentation for filesystem support.

---
 Documentation/filesystems/encoded_io.rst |  74 ++++++++++
 Documentation/filesystems/index.rst      |   1 +
 fs/read_write.c                          | 168 +++++++++++++++++++++--
 include/linux/encoded_io.h               |  17 +++
 include/linux/fs.h                       |  13 ++
 include/uapi/linux/encoded_io.h          |  30 ++++
 include/uapi/linux/fs.h                  |   5 +-
 7 files changed, 294 insertions(+), 14 deletions(-)
 create mode 100644 Documentation/filesystems/encoded_io.rst
 create mode 100644 include/linux/encoded_io.h
 create mode 100644 include/uapi/linux/encoded_io.h
Documentation/filesystems/encoded_io.rst new file +74 -0
new file mode 100644
index 000000000000..50405276d866
@@ -0,0 +1,74 @@
+===========
+Encoded I/O
+===========
+
+Encoded I/O is a mechanism for reading and writing encoded (e.g., compressed
+and/or encrypted) data directly from/to the filesystem. The userspace interface
+is thoroughly described in the :manpage:`encoded_io(7)` man page; this document
+describes the requirements for filesystem support.
+
+First of all, a filesystem supporting encoded I/O must indicate this by setting
+the ``FMODE_ENCODED_IO`` flag in its ``file_open`` file operation::
+
+    static int foo_file_open(struct inode *inode, struct file *filp)
+    {
+            ...
+            filep->f_mode |= FMODE_ENCODED_IO;
+            ...
+    }
+
+Encoded I/O goes through ``read_iter`` and ``write_iter``, designated by the
+``IOCB_ENCODED`` flag in ``kiocb->ki_flags``.
+
+Reads
+=====
+
+Encoded ``read_iter`` should:
+
+1. Call ``generic_encoded_read_checks()`` to validate the file and buffers
+   provided by userspace.
+2. Initialize the ``encoded_iov`` appropriately.
+3. Copy it to the user with ``copy_encoded_iov_to_iter()``.
+4. Copy the encoded data to the user.
+5. Advance ``kiocb->ki_pos`` by ``encoded_iov->len``.
+6. Return the size of the encoded data read, not including the ``encoded_iov``.
+
+There are a few details to be aware of:
+
+* Encoded ``read_iter`` should support reading unencoded data if the extent is
+  not encoded.
+* If the buffers provided by the user are not large enough to contain an entire
+  encoded extent, then ``read_iter`` should return ``-ENOBUFS``. This is to
+  avoid confusing userspace with truncated data that cannot be properly
+  decoded.
+* Reads in the middle of an encoded extent can be returned by setting
+  ``encoded_iov->unencoded_offset`` to non-zero.
+* Truncated unencoded data (e.g., because the file does not end on a block
+  boundary) may be returned by setting ``encoded_iov->len`` to a value smaller
+  value than ``encoded_iov->unencoded_len - encoded_iov->unencoded_offset``.
+
+Writes
+======
+
+Encoded ``write_iter`` should (in addition to the usual accounting/checks done
+by ``write_iter``):
+
+1. Call ``copy_encoded_iov_from_iter()`` to get and validate the
+   ``encoded_iov``.
+2. Call ``generic_encoded_write_checks()`` instead of
+   ``generic_write_checks()``.
+3. Check that the provided encoding in ``encoded_iov`` is supported.
+4. Advance ``kiocb->ki_pos`` by ``encoded_iov->len``.
+5. Return the size of the encoded data written.
+
+Again, there are a few details:
+
+* Encoded ``write_iter`` doesn't need to support writing unencoded data.
+* ``write_iter`` should either write all of the encoded data or none of it; it
+  must not do partial writes.
+* ``write_iter`` doesn't need to validate the encoded data; a subsequent read
+  may return, e.g., ``-EIO`` if the data is not valid.
+* The user may lie about the unencoded size of the data; a subsequent read
+  should truncate or zero-extend the unencoded data rather than returning an
+  error.
+* Be careful of page cache coherency.
Documentation/filesystems/index.rst +1 -0
index 7be9b46d85d9..258b745ea3d8 100644
@@ -53,6 +53,7 @@ filesystem implementations.
    journalling
    fscrypt
    fsverity
+   encoded_io
 
 Filesystems
 ===========
fs/read_write.c +155 -13

196 lines not on this page · raw message

include/linux/encoded_io.h new file +17 -0
new file mode 100644
index 000000000000..a8cfc0108ba0
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_ENCODED_IO_H
+#define _LINUX_ENCODED_IO_H
+
+#include <uapi/linux/encoded_io.h>
+
+struct encoded_iov;
+struct iov_iter;
+struct kiocb;
+extern int generic_encoded_write_checks(struct kiocb *,
+					const struct encoded_iov *);
+extern int copy_encoded_iov_from_iter(struct encoded_iov *, struct iov_iter *);
+extern ssize_t generic_encoded_read_checks(struct kiocb *, struct iov_iter *);
+extern int copy_encoded_iov_to_iter(const struct encoded_iov *,
+				    struct iov_iter *);
+
+#endif /* _LINUX_ENCODED_IO_H */
include/linux/fs.h +13 -0
index fd47deea7c17..2a0700e4efcc 100644
@@ -178,6 +178,9 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 /* File supports async buffered reads */
 #define FMODE_BUF_RASYNC	((__force fmode_t)0x40000000)
 
+/* File supports encoded IO */
+#define FMODE_ENCODED_IO	((__force fmode_t)0x80000000)
+
 /*
  * Attribute flags.  These should be or-ed together to figure out what
  * has been changed!
@@ -308,6 +311,7 @@ enum rw_hint {
 #define IOCB_SYNC		(__force int) RWF_SYNC
 #define IOCB_NOWAIT		(__force int) RWF_NOWAIT
 #define IOCB_APPEND		(__force int) RWF_APPEND
+#define IOCB_ENCODED		(__force int) RWF_ENCODED
 
 /* non-RWF related bits - start at 16 */
 #define IOCB_EVENTFD		(1 << 16)
@@ -2961,6 +2965,13 @@ extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
 extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
 extern int generic_write_check_limits(struct file *file, loff_t pos,
 		loff_t *count);
+struct encoded_iov;
+extern int generic_encoded_write_checks(struct kiocb *,
+					const struct encoded_iov *);
+extern int copy_encoded_iov_from_iter(struct encoded_iov *, struct iov_iter *);
+extern ssize_t generic_encoded_read_checks(struct kiocb *, struct iov_iter *);
+extern int copy_encoded_iov_to_iter(const struct encoded_iov *,
+				    struct iov_iter *);
 extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
 extern ssize_t generic_file_buffered_read(struct kiocb *iocb,
 		struct iov_iter *to, ssize_t already_read);
@@ -3267,6 +3278,8 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
 			return -EOPNOTSUPP;
 		kiocb_flags |= IOCB_NOIO;
 	}
+	if ((flags & RWF_ENCODED) && !(ki->ki_filp->f_mode & FMODE_ENCODED_IO))
+		return -EOPNOTSUPP;
 	kiocb_flags |= (__force int) (flags & RWF_SUPPORTED);
 	if (flags & RWF_SYNC)
 		kiocb_flags |= IOCB_DSYNC;
include/uapi/linux/encoded_io.h new file +30 -0
new file mode 100644
index 000000000000..cf741453dba4
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_LINUX_ENCODED_IO_H
+#define _UAPI_LINUX_ENCODED_IO_H
+
+#include <linux/types.h>
+
+#define ENCODED_IOV_COMPRESSION_NONE 0
+#define ENCODED_IOV_COMPRESSION_BTRFS_ZLIB 1
+#define ENCODED_IOV_COMPRESSION_BTRFS_ZSTD 2
+#define ENCODED_IOV_COMPRESSION_BTRFS_LZO_4K 3
+#define ENCODED_IOV_COMPRESSION_BTRFS_LZO_8K 4
+#define ENCODED_IOV_COMPRESSION_BTRFS_LZO_16K 5
+#define ENCODED_IOV_COMPRESSION_BTRFS_LZO_32K 6
+#define ENCODED_IOV_COMPRESSION_BTRFS_LZO_64K 7
+#define ENCODED_IOV_COMPRESSION_TYPES 8
+
+#define ENCODED_IOV_ENCRYPTION_NONE 0
+#define ENCODED_IOV_ENCRYPTION_TYPES 1
+
+struct encoded_iov {
+	__aligned_u64 len;
+	__aligned_u64 unencoded_len;
+	__aligned_u64 unencoded_offset;
+	__u32 compression;
+	__u32 encryption;
+};
+
+#define ENCODED_IOV_SIZE_VER0 32
+
+#endif /* _UAPI_LINUX_ENCODED_IO_H */
include/uapi/linux/fs.h +4 -1
index f44eb0a04afd..0800b01524e8 100644
@@ -300,8 +300,11 @@ typedef int __bitwise __kernel_rwf_t;
 /* per-IO O_APPEND */
 #define RWF_APPEND	((__force __kernel_rwf_t)0x00000010)
 
+/* encoded (e.g., compressed and/or encrypted) IO */
+#define RWF_ENCODED	((__force __kernel_rwf_t)0x00000020)
+
 /* mask of flags supported by the kernel */
 #define RWF_SUPPORTED	(RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT |\
-			 RWF_APPEND)
+			 RWF_APPEND | RWF_ENCODED)
 
 #endif /* _UAPI_LINUX_FS_H */
Signature · 1 line
2.30.0
#5 lore raw

PATCH v7 4/10 btrfs: fix check_data_csum() error message for direct I/O

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

Commit 1dae796aabf6 ("btrfs: inode: sink parameter start and len to check_data_csum()") replaced the start parameter to check_data_csum() with page_offset(), but page_offset() is not meaningful for direct I/O pages. Bring back the start parameter.

Fixes 265d4ac03fdf ("btrfs: sink parameter start and len to check_data_csum")
---
 fs/btrfs/inode.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
fs/btrfs/inode.c +9 -5
index ef6cb7b620d0..d2ece8554416 100644
@@ -2947,11 +2947,13 @@ void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
  * @bio_offset:	offset to the beginning of the bio (in bytes)
  * @page:	page where is the data to be verified
  * @pgoff:	offset inside the page
+ * @start:	logical offset in the file
  *
  * The length of such check is always one sector size.
  */
 static int check_data_csum(struct inode *inode, struct btrfs_io_bio *io_bio,
-			   u32 bio_offset, struct page *page, u32 pgoff)
+			   u32 bio_offset, struct page *page, u32 pgoff,
+			   u64 start)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
@@ -2978,8 +2980,8 @@ static int check_data_csum(struct inode *inode, struct btrfs_io_bio *io_bio,
 	kunmap_atomic(kaddr);
 	return 0;
 zeroit:
-	btrfs_print_data_csum_error(BTRFS_I(inode), page_offset(page) + pgoff,
-				    csum, csum_expected, io_bio->mirror_num);
+	btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
+				    io_bio->mirror_num);
 	if (io_bio->device)
 		btrfs_dev_stat_inc_and_print(io_bio->device,
 					     BTRFS_DEV_STAT_CORRUPTION_ERRS);
@@ -3032,7 +3034,8 @@ int btrfs_verify_data_csum(struct btrfs_io_bio *io_bio, u32 bio_offset,
 	     pg_off += sectorsize, bio_offset += sectorsize) {
 		int ret;
 
-		ret = check_data_csum(inode, io_bio, bio_offset, page, pg_off);
+		ret = check_data_csum(inode, io_bio, bio_offset, page, pg_off,
+				      page_offset(page) + pg_off);
 		if (ret < 0)
 			return -EIO;
 	}
@@ -7742,7 +7745,8 @@ static blk_status_t btrfs_check_read_dio_bio(struct inode *inode,
 			ASSERT(pgoff < PAGE_SIZE);
 			if (uptodate &&
 			    (!csum || !check_data_csum(inode, io_bio,
-					bio_offset, bvec.bv_page, pgoff))) {
+						       bio_offset, bvec.bv_page,
+						       pgoff, start))) {
 				clean_io_failure(fs_info, failure_tree, io_tree,
 						 start, bvec.bv_page,
 						 btrfs_ino(BTRFS_I(inode)),
Signature · 1 line
2.30.0
Reviewed-by on v7 4/10
#6 lore raw

Re: [PATCH v7 04/10] btrfs: fix check_data_csum() error message for direct I/O

Quoted 9 lines · Omar Sandoval

From: Omar Sandoval <[email protected]>

Commit 1dae796aabf6 ("btrfs: inode: sink parameter start and len to check_data_csum()") replaced the start parameter to check_data_csum() with page_offset(), but page_offset() is not meaningful for direct I/O pages. Bring back the start parameter.

Fixes 265d4ac03fdf ("btrfs: sink parameter start and len to check_data_csum")

Thanks,

Josef

#7 lore raw

PATCH v7 5/10 btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio()

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

btrfs_csum_one_bio() loops over each filesystem block in the bio while keeping a cursor of its current logical position in the file in order to look up the ordered extent to add the checksums to. However, this doesn't make much sense for compressed extents, as a sector on disk does not correspond to a sector of decompressed file data. It happens to work because 1) the compressed bio always covers one ordered extent and 2) the size of the bio is always less than the size of the ordered extent. However, the second point will not always be true for encoded writes.

Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that it can assume that the bio only covers one ordered extent. Since we're already changing the signature, let's get rid of the contig parameter and make it implied by the offset parameter, similar to the change we recently made to btrfs_lookup_bio_sums(). Additionally, let's rename nr_sectors to blockcount to make it clear that it's the number of filesystem blocks, not the number of 512-byte sectors.

---
 fs/btrfs/compression.c |  5 +++--
 fs/btrfs/ctree.h       |  2 +-
 fs/btrfs/file-item.c   | 35 ++++++++++++++++-------------------
 fs/btrfs/inode.c       |  8 ++++----
 4 files changed, 24 insertions(+), 26 deletions(-)
fs/btrfs/compression.c +3 -2
index 5ae3fa0386b7..d9d1d9e38fc5 100644
@@ -436,7 +436,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 			BUG_ON(ret); /* -ENOMEM */
 
 			if (!skip_sum) {
-				ret = btrfs_csum_one_bio(inode, bio, start, 1);
+				ret = btrfs_csum_one_bio(inode, bio, start,
+							 true);
 				BUG_ON(ret); /* -ENOMEM */
 			}
 
@@ -468,7 +469,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 	BUG_ON(ret); /* -ENOMEM */
 
 	if (!skip_sum) {
-		ret = btrfs_csum_one_bio(inode, bio, start, 1);
+		ret = btrfs_csum_one_bio(inode, bio, start, true);
 		BUG_ON(ret); /* -ENOMEM */
 	}
 
fs/btrfs/ctree.h +1 -1
index 1bd416e5a731..f1b9a9e42cc6 100644
@@ -3051,7 +3051,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,
 			   struct btrfs_ordered_sum *sums);
 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
-				u64 file_start, int contig);
+				u64 offset, bool one_ordered);
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
 			     struct list_head *list, int search_commit);
 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
fs/btrfs/file-item.c +16 -19
index 6ccfc019ad90..82d110c8dc03 100644
@@ -608,28 +608,28 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
  * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
  * @inode:	 Owner of the data inside the bio
  * @bio:	 Contains the data to be checksummed
- * @file_start:  offset in file this bio begins to describe
- * @contig:	 Boolean. If true/1 means all bio vecs in this bio are
- *		 contiguous and they begin at @file_start in the file. False/0
- *		 means this bio can contains potentially discontigous bio vecs
- *		 so the logical offset of each should be calculated separately.
+ * @offset:      If (u64)-1, @bio may contain discontiguous bio vecs, so the
+ *               file offsets are determined from the page offsets in the bio.
+ *               Otherwise, this is the starting file offset of the bio vecs in
+ *               @bio, which must be contiguous.
+ * @one_ordered: If true, @bio only refers to one ordered extent.
  */
 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
-		       u64 file_start, int contig)
+				u64 offset, bool one_ordered)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	struct btrfs_ordered_sum *sums;
 	struct btrfs_ordered_extent *ordered = NULL;
+	const bool page_offsets = (offset == (u64)-1);
 	char *data;
 	struct bvec_iter iter;
 	struct bio_vec bvec;
 	int index;
-	int nr_sectors;
+	int blockcount;
 	unsigned long total_bytes = 0;
 	unsigned long this_sum_bytes = 0;
 	int i;
-	u64 offset;
 	unsigned nofs_flag;
 
 	nofs_flag = memalloc_nofs_save();
@@ -643,18 +643,13 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 	sums->len = bio->bi_iter.bi_size;
 	INIT_LIST_HEAD(&sums->list);
 
-	if (contig)
-		offset = file_start;
-	else
-		offset = 0; /* shut up gcc */
-
 	sums->bytenr = bio->bi_iter.bi_sector << 9;
 	index = 0;
 
 	shash->tfm = fs_info->csum_shash;
 
 	bio_for_each_segment(bvec, bio, iter) {
-		if (!contig)
+		if (page_offsets)
 			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
 
 		if (!ordered) {
@@ -662,13 +657,14 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 			BUG_ON(!ordered); /* Logic error */
 		}
 
-		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
+		blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
 						 bvec.bv_len + fs_info->sectorsize
 						 - 1);
 
-		for (i = 0; i < nr_sectors; i++) {
-			if (offset >= ordered->file_offset + ordered->num_bytes ||
-			    offset < ordered->file_offset) {
+		for (i = 0; i < blockcount; i++) {
+			if (!one_ordered &&
+			    (offset >= ordered->file_offset + ordered->num_bytes ||
+			     offset < ordered->file_offset)) {
 				unsigned long bytes_left;
 
 				sums->len = this_sum_bytes;
@@ -699,7 +695,8 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 					    sums->sums + index);
 			kunmap_atomic(data);
 			index += fs_info->csum_size;
-			offset += fs_info->sectorsize;
+			if (!one_ordered)
+				offset += fs_info->sectorsize;
 			this_sum_bytes += fs_info->sectorsize;
 			total_bytes += fs_info->sectorsize;
 		}
fs/btrfs/inode.c +4 -4
index d2ece8554416..b92c4a1d6d2f 100644
@@ -2214,7 +2214,7 @@ int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
 static blk_status_t btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
 					   u64 dio_file_offset)
 {
-	return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
+	return btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false);
 }
 
 /*
@@ -2282,7 +2282,7 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio,
 					  0, btrfs_submit_bio_start);
 		goto out;
 	} else if (!skip_sum) {
-		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
+		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false);
 		if (ret)
 			goto out;
 	}
@@ -7820,7 +7820,7 @@ static blk_status_t btrfs_submit_bio_start_direct_io(struct inode *inode,
 						     struct bio *bio,
 						     u64 dio_file_offset)
 {
-	return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, 1);
+	return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, false);
 }
 
 static void btrfs_end_dio_bio(struct bio *bio)
@@ -7877,7 +7877,7 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
 		 * If we aren't doing async submit, calculate the csum of the
 		 * bio now.
 		 */
-		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, 1);
+		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, false);
 		if (ret)
 			goto err;
 	} else {
Signature · 1 line
2.30.0
#8 lore raw

PATCH v7 6/10 btrfs: add ram_bytes and offset to btrfs_ordered_extent

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

Currently, we only create ordered extents when ram_bytes == num_bytes and offset == 0. However, RWF_ENCODED writes may create extents which only refer to a subset of the full unencoded extent, so we need to plumb these fields through the ordered extent infrastructure and pass them down to insert_reserved_file_extent().

Since we're changing the btrfs_add_ordered_extent* signature, let's get rid of the trivial wrappers and add a kernel-doc.

---
 fs/btrfs/inode.c        | 56 ++++++++++++++++++---------------
 fs/btrfs/ordered-data.c | 68 ++++++++++++++++-------------------------
 fs/btrfs/ordered-data.h | 16 ++++------
 3 files changed, 64 insertions(+), 76 deletions(-)
fs/btrfs/inode.c +32 -24
index b92c4a1d6d2f..139d690f171e 100644
@@ -912,13 +912,12 @@ static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
 			goto out_free_reserve;
 		free_extent_map(em);
 
-		ret = btrfs_add_ordered_extent_compress(inode,
-						async_extent->start,
-						ins.objectid,
-						async_extent->ram_size,
-						ins.offset,
-						BTRFS_ORDERED_COMPRESSED,
-						async_extent->compress_type);
+		ret = btrfs_add_ordered_extent(inode, async_extent->start,
+					       async_extent->ram_size,
+					       async_extent->ram_size,
+					       ins.objectid, ins.offset, 0,
+					       1 << BTRFS_ORDERED_COMPRESSED,
+					       async_extent->compress_type);
 		if (ret) {
 			btrfs_drop_extent_cache(inode, async_extent->start,
 						async_extent->start +
@@ -1126,8 +1125,9 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 		}
 		free_extent_map(em);
 
-		ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
-					       ram_size, cur_alloc_size, 0);
+		ret = btrfs_add_ordered_extent(inode, start, ram_size, ram_size,
+					       ins.objectid, cur_alloc_size, 0,
+					       0, BTRFS_COMPRESS_NONE);
 		if (ret)
 			goto out_drop_extent_cache;
 
@@ -1768,10 +1768,11 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
 				goto error;
 			}
 			free_extent_map(em);
-			ret = btrfs_add_ordered_extent(inode, cur_offset,
-						       disk_bytenr, num_bytes,
-						       num_bytes,
-						       BTRFS_ORDERED_PREALLOC);
+			ret = btrfs_add_ordered_extent(inode,
+					cur_offset, num_bytes, num_bytes,
+					disk_bytenr, num_bytes, 0,
+					1 << BTRFS_ORDERED_PREALLOC,
+					BTRFS_COMPRESS_NONE);
 			if (ret) {
 				btrfs_drop_extent_cache(inode, cur_offset,
 							cur_offset + num_bytes - 1,
@@ -1780,9 +1781,11 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
 			}
 		} else {
 			ret = btrfs_add_ordered_extent(inode, cur_offset,
+						       num_bytes, num_bytes,
 						       disk_bytenr, num_bytes,
-						       num_bytes,
-						       BTRFS_ORDERED_NOCOW);
+						       0,
+						       1 << BTRFS_ORDERED_NOCOW,
+						       BTRFS_COMPRESS_NONE);
 			if (ret)
 				goto error;
 		}
@@ -2586,6 +2589,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_key ins;
 	u64 disk_num_bytes = btrfs_stack_file_extent_disk_num_bytes(stack_fi);
 	u64 disk_bytenr = btrfs_stack_file_extent_disk_bytenr(stack_fi);
+	u64 offset = btrfs_stack_file_extent_offset(stack_fi);
 	u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
 	u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
 	struct btrfs_drop_extents_args drop_args = { 0 };
@@ -2660,7 +2664,8 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 		goto out;
 
 	ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode),
-					       file_pos, qgroup_reserved, &ins);
+					       file_pos - offset,
+					       qgroup_reserved, &ins);
 out:
 	btrfs_free_path(path);
 
@@ -2686,20 +2691,20 @@ static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
 					     struct btrfs_ordered_extent *oe)
 {
 	struct btrfs_file_extent_item stack_fi;
-	u64 logical_len;
 	bool update_inode_bytes;
+	u64 num_bytes = oe->num_bytes;
+	u64 ram_bytes = oe->ram_bytes;
 
 	memset(&stack_fi, 0, sizeof(stack_fi));
 	btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_REG);
 	btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, oe->disk_bytenr);
 	btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi,
 						   oe->disk_num_bytes);
+	btrfs_set_stack_file_extent_offset(&stack_fi, oe->offset);
 	if (test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags))
-		logical_len = oe->truncated_len;
-	else
-		logical_len = oe->num_bytes;
-	btrfs_set_stack_file_extent_num_bytes(&stack_fi, logical_len);
-	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, logical_len);
+		num_bytes = ram_bytes = oe->truncated_len;
+	btrfs_set_stack_file_extent_num_bytes(&stack_fi, num_bytes);
+	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, ram_bytes);
 	btrfs_set_stack_file_extent_compression(&stack_fi, oe->compress_type);
 	/* Encryption and other encoding is reserved and all 0 */
 
@@ -7053,8 +7058,11 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
 		if (IS_ERR(em))
 			goto out;
 	}
-	ret = btrfs_add_ordered_extent_dio(inode, start, block_start, len,
-					   block_len, type);
+	ret = btrfs_add_ordered_extent(inode, start, len, len, block_start,
+				       block_len, 0,
+				       (1 << type) |
+				       (1 << BTRFS_ORDERED_DIRECT),
+				       BTRFS_COMPRESS_NONE);
 	if (ret) {
 		if (em) {
 			free_extent_map(em);
fs/btrfs/ordered-data.c +26 -42

104 lines not on this page · raw message

fs/btrfs/ordered-data.h +6 -10
index 46194c2c05d4..8c8d6ed7a350 100644
@@ -72,9 +72,11 @@ struct btrfs_ordered_extent {
 	 * These fields directly correspond to the same fields in
 	 * btrfs_file_extent_item.
 	 */
-	u64 disk_bytenr;
 	u64 num_bytes;
+	u64 ram_bytes;
+	u64 disk_bytenr;
 	u64 disk_num_bytes;
+	u64 offset;
 
 	/* number of bytes that still need writing */
 	u64 bytes_left;
@@ -160,15 +162,9 @@ bool btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
 				   u64 *file_offset, u64 io_size,
 				   int uptodate);
 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
-			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
-			     int type);
-int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
-				 u64 disk_bytenr, u64 num_bytes,
-				 u64 disk_num_bytes, int type);
-int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
-				      u64 disk_bytenr, u64 num_bytes,
-				      u64 disk_num_bytes, int type,
-				      int compress_type);
+			     u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
+			     u64 disk_num_bytes, u64 offset, int flags,
+			     int compress_type);
 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 			   struct btrfs_ordered_sum *sum);
 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
Signature · 1 line
2.30.0
#9 lore raw

PATCH v7 7/10 btrfs: support different disk extent size for delalloc

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

Currently, we always reserve the same extent size in the file and extent size on disk for delalloc because the former is the worst case for the latter. For RWF_ENCODED writes, we know the exact size of the extent on disk, which may be less than or greater than (for bookends) the size in the file. Add a disk_num_bytes parameter to btrfs_delalloc_reserve_metadata() so that we can reserve the correct amount of csum bytes. No functional change.

---
 fs/btrfs/ctree.h          |  3 ++-
 fs/btrfs/delalloc-space.c | 18 ++++++++++--------
 fs/btrfs/file.c           |  3 ++-
 fs/btrfs/inode.c          |  2 +-
 fs/btrfs/relocation.c     |  4 ++--
 5 files changed, 17 insertions(+), 13 deletions(-)
fs/btrfs/ctree.h +2 -1
index f1b9a9e42cc6..3a0c4fb4c657 100644
@@ -2746,7 +2746,8 @@ void btrfs_subvolume_release_metadata(struct btrfs_root *root,
 				      struct btrfs_block_rsv *rsv);
 void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes);
 
-int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes);
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				    u64 disk_num_bytes);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end);
fs/btrfs/delalloc-space.c +10 -8
index bacee09b7bfd..948b78f03f63 100644
@@ -265,11 +265,11 @@ static void btrfs_calculate_inode_block_rsv_size(struct btrfs_fs_info *fs_info,
 }
 
 static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
-				    u64 num_bytes, u64 *meta_reserve,
-				    u64 *qgroup_reserve)
+				    u64 num_bytes, u64 disk_num_bytes,
+				    u64 *meta_reserve, u64 *qgroup_reserve)
 {
 	u64 nr_extents = count_max_extents(num_bytes);
-	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, num_bytes);
+	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, disk_num_bytes);
 	u64 inode_update = btrfs_calc_metadata_size(fs_info, 1);
 
 	*meta_reserve = btrfs_calc_insert_metadata_size(fs_info,
@@ -283,7 +283,8 @@ static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
 	*qgroup_reserve = nr_extents * fs_info->nodesize;
 }
 
-int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				    u64 disk_num_bytes)
 {
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -313,6 +314,7 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	}
 
 	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
+	disk_num_bytes = ALIGN(disk_num_bytes, fs_info->sectorsize);
 
 	/*
 	 * We always want to do it this way, every other way is wrong and ends
@@ -324,8 +326,8 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	 * everything out and try again, which is bad.  This way we just
 	 * over-reserve slightly, and clean up the mess when we are done.
 	 */
-	calc_inode_reservations(fs_info, num_bytes, &meta_reserve,
-				&qgroup_reserve);
+	calc_inode_reservations(fs_info, num_bytes, disk_num_bytes,
+				&meta_reserve, &qgroup_reserve);
 	ret = btrfs_qgroup_reserve_meta_prealloc(root, qgroup_reserve, true);
 	if (ret)
 		return ret;
@@ -344,7 +346,7 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	spin_lock(&inode->lock);
 	nr_extents = count_max_extents(num_bytes);
 	btrfs_mod_outstanding_extents(inode, nr_extents);
-	inode->csum_bytes += num_bytes;
+	inode->csum_bytes += disk_num_bytes;
 	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
 	spin_unlock(&inode->lock);
 
@@ -448,7 +450,7 @@ int btrfs_delalloc_reserve_space(struct btrfs_inode *inode,
 	ret = btrfs_check_data_free_space(inode, reserved, start, len);
 	if (ret < 0)
 		return ret;
-	ret = btrfs_delalloc_reserve_metadata(inode, len);
+	ret = btrfs_delalloc_reserve_metadata(inode, len, len);
 	if (ret < 0)
 		btrfs_free_reserved_data_space(inode, *reserved, start, len);
 	return ret;
fs/btrfs/file.c +2 -1
index d81ae1f518f2..32578f31cf43 100644
@@ -1733,7 +1733,8 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 					 fs_info->sectorsize);
 		WARN_ON(reserve_bytes == 0);
 		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
-				reserve_bytes);
+						      reserve_bytes,
+						      reserve_bytes);
 		if (ret) {
 			if (!only_release_metadata)
 				btrfs_free_reserved_data_space(BTRFS_I(inode),
fs/btrfs/inode.c +1 -1
index 139d690f171e..3c1f1297c9d9 100644
@@ -4712,7 +4712,7 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
 			goto out;
 		}
 	}
-	ret = btrfs_delalloc_reserve_metadata(inode, blocksize);
+	ret = btrfs_delalloc_reserve_metadata(inode, blocksize, blocksize);
 	if (ret < 0) {
 		if (!only_release_metadata)
 			btrfs_free_reserved_data_space(inode, data_reserved,
fs/btrfs/relocation.c +2 -2
index 9f2289bcdde6..85e9e7287bfd 100644
@@ -2660,8 +2660,8 @@ static int relocate_file_extent_cluster(struct inode *inode,
 	index = (cluster->start - offset) >> PAGE_SHIFT;
 	last_index = (cluster->end - offset) >> PAGE_SHIFT;
 	while (index <= last_index) {
-		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
-				PAGE_SIZE);
+		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), PAGE_SIZE,
+						      PAGE_SIZE);
 		if (ret)
 			goto out;
 
Signature · 1 line
2.30.0
#10 lore raw

PATCH v7 8/10 btrfs: optionally extend i_size in cow_file_range_inline()

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

Currently, an inline extent is always created after i_size is extended from btrfs_dirty_pages(). However, for encoded writes, we only want to update i_size after we successfully created the inline extent. Add an update_i_size parameter to cow_file_range_inline() and insert_inline_extent() and pass in the size of the extent rather than determining it from i_size. Since the start parameter is always passed as 0, get rid of it and simplify the logic in these two functions. While we're here, let's document the requirements for creating an inline extent.

---
 fs/btrfs/inode.c | 100 +++++++++++++++++++++++------------------------
 1 file changed, 48 insertions(+), 52 deletions(-)
fs/btrfs/inode.c +48 -52
index 3c1f1297c9d9..b362e73af840 100644
@@ -203,9 +203,10 @@ static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
 static int insert_inline_extent(struct btrfs_trans_handle *trans,
 				struct btrfs_path *path, bool extent_inserted,
 				struct btrfs_root *root, struct inode *inode,
-				u64 start, size_t size, size_t compressed_size,
+				size_t size, size_t compressed_size,
 				int compress_type,
-				struct page **compressed_pages)
+				struct page **compressed_pages,
+				bool update_i_size)
 {
 	struct extent_buffer *leaf;
 	struct page *page = NULL;
@@ -214,7 +215,7 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_file_extent_item *ei;
 	int ret;
 	size_t cur_size = size;
-	unsigned long offset;
+	u64 i_size;
 
 	ASSERT((compressed_size > 0 && compressed_pages) ||
 	       (compressed_size == 0 && !compressed_pages));
@@ -227,7 +228,7 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		size_t datasize;
 
 		key.objectid = btrfs_ino(BTRFS_I(inode));
-		key.offset = start;
+		key.offset = 0;
 		key.type = BTRFS_EXTENT_DATA_KEY;
 
 		datasize = btrfs_file_extent_calc_inline_size(cur_size);
@@ -265,12 +266,10 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		btrfs_set_file_extent_compression(leaf, ei,
 						  compress_type);
 	} else {
-		page = find_get_page(inode->i_mapping,
-				     start >> PAGE_SHIFT);
+		page = find_get_page(inode->i_mapping, 0);
 		btrfs_set_file_extent_compression(leaf, ei, 0);
 		kaddr = kmap_atomic(page);
-		offset = offset_in_page(start);
-		write_extent_buffer(leaf, kaddr + offset, ptr, size);
+		write_extent_buffer(leaf, kaddr, ptr, size);
 		kunmap_atomic(kaddr);
 		put_page(page);
 	}
@@ -281,8 +280,8 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	 * We align size to sectorsize for inline extents just for simplicity
 	 * sake.
 	 */
-	size = ALIGN(size, root->fs_info->sectorsize);
-	ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start, size);
+	ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
+					ALIGN(size, root->fs_info->sectorsize));
 	if (ret)
 		goto fail;
 
@@ -295,7 +294,13 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	 * before we unlock the pages.  Otherwise we
 	 * could end up racing with unlink.
 	 */
-	BTRFS_I(inode)->disk_i_size = inode->i_size;
+	i_size = i_size_read(inode);
+	if (update_i_size && size > i_size) {
+		i_size_write(inode, size);
+		i_size = size;
+	}
+	BTRFS_I(inode)->disk_i_size = i_size;
+
 fail:
 	return ret;
 }
@@ -306,35 +311,31 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
  * does the checks required to make sure the data is small enough
  * to fit as an inline extent.
  */
-static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
-					  u64 end, size_t compressed_size,
+static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
+					  size_t compressed_size,
 					  int compress_type,
-					  struct page **compressed_pages)
+					  struct page **compressed_pages,
+					  bool update_i_size)
 {
 	struct btrfs_drop_extents_args drop_args = { 0 };
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_trans_handle *trans;
-	u64 isize = i_size_read(&inode->vfs_inode);
-	u64 actual_end = min(end + 1, isize);
-	u64 inline_len = actual_end - start;
-	u64 aligned_end = ALIGN(end, fs_info->sectorsize);
-	u64 data_len = inline_len;
+	u64 data_len = compressed_size ? compressed_size : size;
 	int ret;
 	struct btrfs_path *path;
 
-	if (compressed_size)
-		data_len = compressed_size;
-
-	if (start > 0 ||
-	    actual_end > fs_info->sectorsize ||
+	/*
+	 * We can create an inline extent if it ends at or beyond the current
+	 * i_size, is no larger than a sector (decompressed), and the (possibly
+	 * compressed) data fits in a leaf and the configured maximum inline
+	 * size.
+	 */
+	if (size < i_size_read(&inode->vfs_inode) ||
+	    size > fs_info->sectorsize ||
 	    data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
-	    (!compressed_size &&
-	    (actual_end & (fs_info->sectorsize - 1)) == 0) ||
-	    end + 1 < isize ||
-	    data_len > fs_info->max_inline) {
+	    data_len > fs_info->max_inline)
 		return 1;
-	}
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -348,30 +349,21 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
 	trans->block_rsv = &inode->block_rsv;
 
 	drop_args.path = path;
-	drop_args.start = start;
-	drop_args.end = aligned_end;
+	drop_args.start = 0;
+	drop_args.end = fs_info->sectorsize;
 	drop_args.drop_cache = true;
 	drop_args.replace_extent = true;
-
-	if (compressed_size && compressed_pages)
-		drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
-		   compressed_size);
-	else
-		drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
-		    inline_len);
-
+	drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(data_len);
 	ret = btrfs_drop_extents(trans, root, inode, &drop_args);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto out;
 	}
 
-	if (isize > actual_end)
-		inline_len = min_t(u64, isize, actual_end);
-	ret = insert_inline_extent(trans, path, drop_args.extent_inserted,
-				   root, &inode->vfs_inode, start,
-				   inline_len, compressed_size,
-				   compress_type, compressed_pages);
+	ret = insert_inline_extent(trans, path, drop_args.extent_inserted, root,
+				   &inode->vfs_inode, size, compressed_size,
+				   compress_type, compressed_pages,
+				   update_i_size);
 	if (ret && ret != -ENOSPC) {
 		btrfs_abort_transaction(trans, ret);
 		goto out;
@@ -380,7 +372,7 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
 		goto out;
 	}
 
-	btrfs_update_inode_bytes(inode, inline_len, drop_args.bytes_found);
+	btrfs_update_inode_bytes(inode, size, drop_args.bytes_found);
 	ret = btrfs_update_inode(trans, root, inode);
 	if (ret && ret != -ENOSPC) {
 		btrfs_abort_transaction(trans, ret);
@@ -661,14 +653,15 @@ static noinline int compress_file_range(struct async_chunk *async_chunk)
 			/* we didn't compress the entire range, try
 			 * to make an uncompressed inline extent.
 			 */
-			ret = cow_file_range_inline(BTRFS_I(inode), start, end,
+			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
 						    0, BTRFS_COMPRESS_NONE,
-						    NULL);
+						    NULL, false);
 		} else {
 			/* try making a compressed inline extent */
-			ret = cow_file_range_inline(BTRFS_I(inode), start, end,
+			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
 						    total_compressed,
-						    compress_type, pages);
+						    compress_type, pages,
+						    false);
 		}
 		if (ret <= 0) {
 			unsigned long clear_flags = EXTENT_DELALLOC |
@@ -1056,9 +1049,12 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 	inode_should_defrag(inode, start, end, num_bytes, SZ_64K);
 
 	if (start == 0) {
+		u64 actual_end = min_t(u64, i_size_read(&inode->vfs_inode),
+				       end + 1);
+
 		/* lets try to make an inline extent */
-		ret = cow_file_range_inline(inode, start, end, 0,
-					    BTRFS_COMPRESS_NONE, NULL);
+		ret = cow_file_range_inline(inode, actual_end, 0,
+					    BTRFS_COMPRESS_NONE, NULL, false);
 		if (ret == 0) {
 			/*
 			 * We use DO_ACCOUNTING here because we need the
Signature · 1 line
2.30.0
#11 lore raw

PATCH v7 9/10 btrfs: implement RWF_ENCODED reads

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

There are 4 main cases:

1. Inline extents: we copy the data straight out of the extent buffer.
2. Hole/preallocated extents: we fill in zeroes.
3. Regular, uncompressed extents: we read the sectors we need directly from disk.
4. Regular, compressed extents: we read the entire compressed extent from disk and indicate what subset of the decompressed extent is in the file.

This initial implementation simplifies a few things that can be improved in the future:

- We hold the inode lock during the operation.
- Cases 1, 3, and 4 allocate temporary memory to read into before copying out to userspace.
- We don't do read repair, because it turns out that read repair is currently broken for compressed data.

---
 fs/btrfs/ctree.h |   2 +
 fs/btrfs/file.c  |   5 +
 fs/btrfs/inode.c | 497 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 504 insertions(+)
fs/btrfs/ctree.h +2 -0
index 3a0c4fb4c657..d093f7a900d7 100644
@@ -3157,6 +3157,8 @@ int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page
 int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end);
 void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
 					  u64 end, int uptodate);
+ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter);
+
 extern const struct dentry_operations btrfs_dentry_operations;
 extern const struct iomap_ops btrfs_dio_iomap_ops;
 extern const struct iomap_dio_ops btrfs_dio_ops;
fs/btrfs/file.c +5 -0
index 32578f31cf43..88eb4c5ddd52 100644
@@ -3630,6 +3630,11 @@ static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	ssize_t ret = 0;
 
+	if (iocb->ki_flags & IOCB_ENCODED) {
+		if (iocb->ki_flags & IOCB_NOWAIT)
+			return -EOPNOTSUPP;
+		return btrfs_encoded_read(iocb, to);
+	}
 	if (iocb->ki_flags & IOCB_DIRECT) {
 		ret = btrfs_direct_read(iocb, to);
 		if (ret < 0 || !iov_iter_count(to) ||
fs/btrfs/inode.c +497 -0

509 lines not on this page · raw message

Signature · 1 line
2.30.0
#12 lore raw

PATCH v7 10/10 btrfs: implement RWF_ENCODED writes

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

The implementation resembles direct I/O: we have to flush any ordered extents, invalidate the page cache, and do the io tree/delalloc/extent map/ordered extent dance. From there, we can reuse the compression code with a minor modification to distinguish the write from writeback. This also creates inline extents when possible.

Now that read and write are implemented, this also sets the FMODE_ENCODED_IO flag in btrfs_file_open().

---
 fs/btrfs/compression.c  |   7 +-
 fs/btrfs/compression.h  |   6 +-
 fs/btrfs/ctree.h        |   2 +
 fs/btrfs/file.c         |  38 +++++-
 fs/btrfs/inode.c        | 259 +++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/ordered-data.c |  12 +-
 fs/btrfs/ordered-data.h |   2 +
 7 files changed, 314 insertions(+), 12 deletions(-)
fs/btrfs/compression.c +5 -2
index d9d1d9e38fc5..4cfd03918ffc 100644
@@ -336,7 +336,8 @@ static void end_compressed_bio_write(struct bio *bio)
 			bio->bi_status == BLK_STS_OK);
 	cb->compressed_pages[0]->mapping = NULL;
 
-	end_compressed_writeback(inode, cb);
+	if (cb->writeback)
+		end_compressed_writeback(inode, cb);
 	/* note, our inode could be gone now */
 
 	/*
@@ -372,7 +373,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				 struct page **compressed_pages,
 				 unsigned long nr_pages,
 				 unsigned int write_flags,
-				 struct cgroup_subsys_state *blkcg_css)
+				 struct cgroup_subsys_state *blkcg_css,
+				 bool writeback)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	struct bio *bio = NULL;
@@ -396,6 +398,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 	cb->mirror_num = 0;
 	cb->compressed_pages = compressed_pages;
 	cb->compressed_len = compressed_len;
+	cb->writeback = writeback;
 	cb->orig_bio = NULL;
 	cb->nr_pages = nr_pages;
 
fs/btrfs/compression.h +5 -1
index 8001b700ea3a..f95cdc16f503 100644
@@ -49,6 +49,9 @@ struct compressed_bio {
 	/* the compression algorithm for this bio */
 	int compress_type;
 
+	/* Whether this is a write for writeback. */
+	bool writeback;
+
 	/* number of compressed pages in the array */
 	unsigned long nr_pages;
 
@@ -96,7 +99,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				  struct page **compressed_pages,
 				  unsigned long nr_pages,
 				  unsigned int write_flags,
-				  struct cgroup_subsys_state *blkcg_css);
+				  struct cgroup_subsys_state *blkcg_css,
+				  bool writeback);
 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				 int mirror_num, unsigned long bio_flags);
 
fs/btrfs/ctree.h +2 -0
index d093f7a900d7..33a08ab5cb0e 100644
@@ -3158,6 +3158,8 @@ int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end);
 void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
 					  u64 end, int uptodate);
 ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter);
+ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
+			       struct encoded_iov *encoded);
 
 extern const struct dentry_operations btrfs_dentry_operations;
 extern const struct iomap_ops btrfs_dio_iomap_ops;
fs/btrfs/file.c +34 -4
index 88eb4c5ddd52..dd7fec85fea1 100644
@@ -3,6 +3,7 @@
  * Copyright (C) 2007 Oracle.  All rights reserved.
  */
 
+#include <linux/encoded_io.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
 #include <linux/time.h>
@@ -1993,6 +1994,32 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
 	return written ? written : err;
 }
 
+static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	struct encoded_iov encoded;
+	ssize_t ret;
+
+	ret = copy_encoded_iov_from_iter(&encoded, from);
+	if (ret)
+		return ret;
+
+	btrfs_inode_lock(inode, 0);
+	ret = generic_encoded_write_checks(iocb, &encoded);
+	if (ret || encoded.len == 0)
+		goto out;
+
+	ret = btrfs_write_check(iocb, from, encoded.len);
+	if (ret < 0)
+		goto out;
+
+	ret = btrfs_do_encoded_write(iocb, from, &encoded);
+out:
+	btrfs_inode_unlock(inode, 0);
+	return ret;
+}
+
 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 				    struct iov_iter *from)
 {
@@ -2009,14 +2036,17 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	if (test_bit(BTRFS_FS_STATE_ERROR, &inode->root->fs_info->fs_state))
 		return -EROFS;
 
-	if (!(iocb->ki_flags & IOCB_DIRECT) &&
-	    (iocb->ki_flags & IOCB_NOWAIT))
+	if ((iocb->ki_flags & IOCB_NOWAIT) &&
+	    (!(iocb->ki_flags & IOCB_DIRECT) ||
+	     (iocb->ki_flags & IOCB_ENCODED)))
 		return -EOPNOTSUPP;
 
 	if (sync)
 		atomic_inc(&inode->sync_writers);
 
-	if (iocb->ki_flags & IOCB_DIRECT)
+	if (iocb->ki_flags & IOCB_ENCODED)
+		num_written = btrfs_encoded_write(iocb, from);
+	else if (iocb->ki_flags & IOCB_DIRECT)
 		num_written = btrfs_direct_write(iocb, from);
 	else
 		num_written = btrfs_buffered_write(iocb, from);
@@ -3587,7 +3617,7 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
 
 static int btrfs_file_open(struct inode *inode, struct file *filp)
 {
-	filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
+	filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC | FMODE_ENCODED_IO;
 	return generic_file_open(inode, filp);
 }
 
fs/btrfs/inode.c +257 -2

283 lines not on this page · raw message

fs/btrfs/ordered-data.c +9 -3
index e11a517fab10..00329d82337e 100644
@@ -472,9 +472,15 @@ void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 	spin_lock(&btrfs_inode->lock);
 	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 	spin_unlock(&btrfs_inode->lock);
-	if (root != fs_info->tree_root)
-		btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes,
-						false);
+	if (root != fs_info->tree_root) {
+		u64 release;
+
+		if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
+			release = entry->disk_num_bytes;
+		else
+			release = entry->num_bytes;
+		btrfs_delalloc_release_metadata(btrfs_inode, release, false);
+	}
 
 	if (test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 		percpu_counter_add_batch(&fs_info->dio_bytes, -entry->num_bytes,
fs/btrfs/ordered-data.h +2 -0
index 8c8d6ed7a350..67c72485bd90 100644
@@ -62,6 +62,8 @@ enum {
 	BTRFS_ORDERED_LOGGED_CSUM,
 	/* We wait for this extent to complete in the current transaction */
 	BTRFS_ORDERED_PENDING,
+	/* RWF_ENCODED I/O */
+	BTRFS_ORDERED_ENCODED,
 };
 
 struct btrfs_ordered_extent {
Signature · 1 line
2.30.0
#13 lore raw

PATCH v7 1/1 Document encoded I/O

In reply to Omar Sandoval

From: Omar Sandoval <[email protected]>

This adds a new page, encoded_io(7), providing an overview of encoded I/O and updates fcntl(2), open(2), and preadv2(2)/pwritev2(2) to reference it.

Cc Michael Kerrisk <[email protected]>
Cc linux-man <[email protected]>
---
 man2/fcntl.2      |   8 +
 man2/open.2       |  13 ++
 man2/readv.2      |  69 +++++++++
 man7/encoded_io.7 | 369 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 459 insertions(+)
 create mode 100644 man7/encoded_io.7
man2/fcntl.2 +8 -0
index a15f467ef..1081cb70f 100644
@@ -217,6 +217,7 @@ in
 .I arg
 are ignored.
 On Linux, this command can change only the
+.BR O_ALLOW_ENCODED ,
 .BR O_APPEND ,
 .BR O_ASYNC ,
 .BR O_DIRECT ,
@@ -1815,6 +1816,13 @@ and the soft or hard user pipe limit has been reached; see
 .BR pipe (7).
 .TP
 .B EPERM
+Attempted to set the
+.B O_ALLOW_ENCODED
+flag and the calling process did not have the
+.B CAP_SYS_ADMIN
+capability.
+.TP
+.B EPERM
 Attempted to clear the
 .B O_APPEND
 flag on a file that has the append-only attribute set.
man2/open.2 +13 -0
index b30dc1532..6aab44b6d 100644
@@ -180,6 +180,14 @@ for details.
 .PP
 The full list of file creation flags and file status flags is as follows:
 .TP
+.B O_ALLOW_ENCODED
+Open the file with encoded I/O permissions;
+see
+.BR encoded_io (7).
+The caller must have the
+.B CAP_SYS_ADMIN
+capability.
+.TP
 .B O_APPEND
 The file is opened in append mode.
 Before each
@@ -1232,6 +1240,11 @@ did not match the owner of the file and the caller was not privileged.
 The operation was prevented by a file seal; see
 .BR fcntl (2).
 .TP
+.B EPERM
+The
+.B O_ALLOW_ENCODED
+flag was specified, but the caller was not privileged.
+.TP
 .B EROFS
 .I pathname
 refers to a file on a read-only filesystem and write access was
man2/readv.2 +69 -0

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man7/encoded_io.7 new file +369 -0

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Signature · 1 line
2.30.0
#14 lore raw
In reply to Omar Sandoval
Quoted 16 lines · Omar Sandoval

From: Omar Sandoval <[email protected]>

This series adds an API for reading compressed data on a filesystem without decompressing it as well as support for writing compressed data directly to the filesystem. As with the previous submissions, I've included a man page patch describing the API. I have test cases (including fsstress support) and example programs which I'll send up [1].

The main use-case is Btrfs send/receive: currently, when sending data from one compressed filesystem to another, the sending side decompresses the data and the receiving side recompresses it before writing it out. This is wasteful and can be avoided if we can just send and write compressed extents. The patches implementing the send/receive support will be sent shortly.

Quoted 8 lines

Patches 1-3 add the VFS support and UAPI. Patch 4 is a fix that this series depends on; it can be merged independently. Patches 5-8 are Btrfs prep patches. Patch 9 adds Btrfs encoded read support and patch 10 adds Btrfs encoded write support.

These patches are based on Dave Sterba's Btrfs misc-next branch [2], which is in turn currently based on v5.11-rc4.

Is everybody OK with this? Al? I would like to go ahead and get this merged for the next merge window as long as everybody is OK with it, as it's blocking a fair bit of BTRFS work. Thanks,

Josef

#15 lore raw
Quoted 22 lines · Josef Bacik
Quoted 21 lines · Omar Sandoval

From: Omar Sandoval <[email protected]>

This series adds an API for reading compressed data on a filesystem without decompressing it as well as support for writing compressed data directly to the filesystem. As with the previous submissions, I've included a man page patch describing the API. I have test cases (including fsstress support) and example programs which I'll send up [1].

The main use-case is Btrfs send/receive: currently, when sending data from one compressed filesystem to another, the sending side decompresses the data and the receiving side recompresses it before writing it out. This is wasteful and can be avoided if we can just send and write compressed extents. The patches implementing the send/receive support will be sent shortly.

Patches 1-3 add the VFS support and UAPI. Patch 4 is a fix that this series depends on; it can be merged independently. Patches 5-8 are Btrfs prep patches. Patch 9 adds Btrfs encoded read support and patch 10 adds Btrfs encoded write support.

Quoted 7 lines
Quoted 3 lines

These patches are based on Dave Sterba's Btrfs misc-next branch [2], which is in turn currently based on v5.11-rc4.

Is everybody OK with this? Al? I would like to go ahead and get this merged for the next merge window as long as everybody is OK with it, as it's blocking a fair bit of BTRFS work. Thanks,

Ping. Al, Christoph, any thoughts?