From ea0213e0c7cc1c1b52badf27bd7db4f50a67baaa Mon Sep 17 00:00:00 2001 From: Artur Paszkiewicz Date: Thu, 9 Mar 2017 09:59:57 +0100 Subject: md: superblock changes for PPL Include information about PPL location and size into mdp_superblock_1 and copy it to/from rdev. Because PPL is mutually exclusive with bitmap, put it in place of 'bitmap_offset'. Add a new flag MD_FEATURE_PPL for 'feature_map', analogically to MD_FEATURE_BITMAP_OFFSET. Add MD_HAS_PPL to mddev->flags to indicate that PPL is enabled on an array. Signed-off-by: Artur Paszkiewicz Signed-off-by: Shaohua Li --- include/uapi/linux/raid/md_p.h | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h index 9930f3e9040f..fe2112810c43 100644 --- a/include/uapi/linux/raid/md_p.h +++ b/include/uapi/linux/raid/md_p.h @@ -242,10 +242,18 @@ struct mdp_superblock_1 { __le32 chunksize; /* in 512byte sectors */ __le32 raid_disks; - __le32 bitmap_offset; /* sectors after start of superblock that bitmap starts - * NOTE: signed, so bitmap can be before superblock - * only meaningful of feature_map[0] is set. - */ + union { + __le32 bitmap_offset; /* sectors after start of superblock that bitmap starts + * NOTE: signed, so bitmap can be before superblock + * only meaningful of feature_map[0] is set. + */ + + /* only meaningful when feature_map[MD_FEATURE_PPL] is set */ + struct { + __le16 offset; /* sectors from start of superblock that ppl starts (signed) */ + __le16 size; /* ppl size in sectors */ + } ppl; + }; /* These are only valid with feature bit '4' */ __le32 new_level; /* new level we are reshaping to */ @@ -318,6 +326,7 @@ struct mdp_superblock_1 { */ #define MD_FEATURE_CLUSTERED 256 /* clustered MD */ #define MD_FEATURE_JOURNAL 512 /* support write cache */ +#define MD_FEATURE_PPL 1024 /* support PPL */ #define MD_FEATURE_ALL (MD_FEATURE_BITMAP_OFFSET \ |MD_FEATURE_RECOVERY_OFFSET \ |MD_FEATURE_RESHAPE_ACTIVE \ @@ -328,6 +337,7 @@ struct mdp_superblock_1 { |MD_FEATURE_RECOVERY_BITMAP \ |MD_FEATURE_CLUSTERED \ |MD_FEATURE_JOURNAL \ + |MD_FEATURE_PPL \ ) struct r5l_payload_header { -- cgit v1.2.3 From 3418d036c81dcb604b7c7c71b209d5890a8418aa Mon Sep 17 00:00:00 2001 From: Artur Paszkiewicz Date: Thu, 9 Mar 2017 09:59:59 +0100 Subject: raid5-ppl: Partial Parity Log write logging implementation Implement the calculation of partial parity for a stripe and PPL write logging functionality. The description of PPL is added to the documentation. More details can be found in the comments in raid5-ppl.c. Attach a page for holding the partial parity data to stripe_head. Allocate it only if mddev has the MD_HAS_PPL flag set. Partial parity is the xor of not modified data chunks of a stripe and is calculated as follows: - reconstruct-write case: xor data from all not updated disks in a stripe - read-modify-write case: xor old data and parity from all updated disks in a stripe Implement it using the async_tx API and integrate into raid_run_ops(). It must be called when we still have access to old data, so do it when STRIPE_OP_BIODRAIN is set, but before ops_run_prexor5(). The result is stored into sh->ppl_page. Partial parity is not meaningful for full stripe write and is not stored in the log or used for recovery, so don't attempt to calculate it when stripe has STRIPE_FULL_WRITE. Put the PPL metadata structures to md_p.h because userspace tools (mdadm) will also need to read/write PPL. Warn about using PPL with enabled disk volatile write-back cache for now. It can be removed once disk cache flushing before writing PPL is implemented. Signed-off-by: Artur Paszkiewicz Signed-off-by: Shaohua Li --- include/uapi/linux/raid/md_p.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h index fe2112810c43..d9a1ead867b9 100644 --- a/include/uapi/linux/raid/md_p.h +++ b/include/uapi/linux/raid/md_p.h @@ -398,4 +398,31 @@ struct r5l_meta_block { #define R5LOG_VERSION 0x1 #define R5LOG_MAGIC 0x6433c509 + +struct ppl_header_entry { + __le64 data_sector; /* raid sector of the new data */ + __le32 pp_size; /* length of partial parity */ + __le32 data_size; /* length of data */ + __le32 parity_disk; /* member disk containing parity */ + __le32 checksum; /* checksum of partial parity data for this + * entry (~crc32c) */ +} __attribute__ ((__packed__)); + +#define PPL_HEADER_SIZE 4096 +#define PPL_HDR_RESERVED 512 +#define PPL_HDR_ENTRY_SPACE \ + (PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(u32) - sizeof(u64)) +#define PPL_HDR_MAX_ENTRIES \ + (PPL_HDR_ENTRY_SPACE / sizeof(struct ppl_header_entry)) + +struct ppl_header { + __u8 reserved[PPL_HDR_RESERVED];/* reserved space, fill with 0xff */ + __le32 signature; /* signature (family number of volume) */ + __le32 padding; /* zero pad */ + __le64 generation; /* generation number of the header */ + __le32 entries_count; /* number of entries in entry array */ + __le32 checksum; /* checksum of the header (~crc32c) */ + struct ppl_header_entry entries[PPL_HDR_MAX_ENTRIES]; +} __attribute__ ((__packed__)); + #endif -- cgit v1.2.3 From fc6d2a3ca59d5656d5b0ac3b25ecf493e4614abd Mon Sep 17 00:00:00 2001 From: Artur Paszkiewicz Date: Wed, 19 Apr 2017 10:48:06 +0200 Subject: uapi: fix linux/raid/md_p.h userspace compilation error Use __le32 and __le64 instead of u32 and u64. This fixes klibc build error: In file included from /klibc/usr/klibc/../include/sys/md.h:30:0, from /klibc/usr/kinit/do_mounts_md.c:19: /linux-next/usr/include/linux/raid/md_p.h:414:51: error: 'u32' undeclared here (not in a function) (PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(u32) - sizeof(u64)) Reported-by: Greg Thelen Reported-by: Nigel Croxon Tested-by: Greg Thelen Signed-off-by: Artur Paszkiewicz Signed-off-by: Shaohua Li --- include/uapi/linux/raid/md_p.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h index d9a1ead867b9..d500bd224979 100644 --- a/include/uapi/linux/raid/md_p.h +++ b/include/uapi/linux/raid/md_p.h @@ -411,7 +411,7 @@ struct ppl_header_entry { #define PPL_HEADER_SIZE 4096 #define PPL_HDR_RESERVED 512 #define PPL_HDR_ENTRY_SPACE \ - (PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(u32) - sizeof(u64)) + (PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(__le32) - sizeof(__le64)) #define PPL_HDR_MAX_ENTRIES \ (PPL_HDR_ENTRY_SPACE / sizeof(struct ppl_header_entry)) -- cgit v1.2.3