freebsd-src/lib/libufs/libufs.h
Kirk McKusick 772430dd67 Ensure I/O buffers in libufs(3) are 128-byte aligned.
Various disk controllers require their buffers to be aligned to a
cache-line size (128 bytes). For buffers allocated in structures,
ensure that they are 128-byte aligned. Use aligned_malloc to allocate
memory to ensure that the returned memory is 128-byte aligned.

While we are here, we replace the dynamically allocated inode buffer
with a buffer allocated in the uufsd structure just as the superblock
and cylinder group buffers do.

This can be removed if/when the kernel is fixed. Because this problem
has existed on one I/O subsystem or another since the 1990's, we
are probably stuck with dealing with it forever.

The problem most recent showed up in Azure, see:
    https://reviews.freebsd.org/D41728
    https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=267654
Before these fixes were applied, it was confirmed that the changes
in this commit also fixed the issue in Azure.

Reviewed-by: Warner Losh, kib
Tested-by:   Souradeep Chakrabarti of Microsoft (earlier version)
PR:          267654
Differential Revision: https://reviews.freebsd.org/D41724
2023-11-17 14:11:24 -08:00

194 lines
5.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2002 Juli Mallett. All rights reserved.
*
* This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
* FreeBSD project. Redistribution and use in source and binary forms, with
* or without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __LIBUFS_H__
#define __LIBUFS_H__
/*
* Various disk controllers require their buffers to be aligned to the size
* of a cache line. The LIBUFS_BUFALIGN defines the required alignment size.
* The alignment must be a power of 2.
*/
#define LIBUFS_BUFALIGN 128
/*
* libufs structures.
*/
union dinodep {
struct ufs1_dinode *dp1;
struct ufs2_dinode *dp2;
};
/*
* userland ufs disk.
*/
struct uufsd {
union {
struct fs d_fs; /* filesystem information */
char d_sb[SBLOCKSIZE]; /* superblock as buffer */
} d_sbunion __aligned(LIBUFS_BUFALIGN);
union {
struct cg d_cg; /* cylinder group */
char d_buf[MAXBSIZE]; /* cylinder group storage */
} d_cgunion __aligned(LIBUFS_BUFALIGN);
union {
union dinodep d_ino[1]; /* inode block */
char d_inos[MAXBSIZE]; /* inode block as buffer */
} d_inosunion __aligned(LIBUFS_BUFALIGN);
const char *d_name; /* disk name */
const char *d_error; /* human readable disk error */
ufs2_daddr_t d_sblock; /* superblock location */
struct fs_summary_info *d_si; /* Superblock summary info */
union dinodep d_dp; /* pointer to currently active inode */
ino_t d_inomin; /* low ino */
ino_t d_inomax; /* high ino */
off_t d_sblockloc; /* where to look for the superblock */
int64_t d_bsize; /* device bsize */
int64_t d_lookupflags; /* flags to superblock lookup */
int64_t d_mine; /* internal flags */
int32_t d_ccg; /* current cylinder group */
int32_t d_ufs; /* decimal UFS version */
int32_t d_fd; /* raw device file descriptor */
int32_t d_lcg; /* last cylinder group (in d_cg) */
};
#define d_inos d_inosunion.d_inos
#define d_fs d_sbunion.d_fs
#define d_cg d_cgunion.d_cg
/*
* libufs macros (internal, non-exported).
*/
#ifdef _LIBUFS
/*
* Ensure that the buffer is aligned to the I/O subsystem requirements.
*/
#define BUF_MALLOC(newbufpp, data, size) { \
if (data != NULL && (((intptr_t)data) & (LIBUFS_BUFALIGN - 1)) == 0) \
*newbufpp = (void *)data; \
else \
*newbufpp = aligned_alloc(LIBUFS_BUFALIGN, size); \
}
/*
* Trace steps through libufs, to be used at entry and erroneous return.
*/
static inline void
ERROR(struct uufsd *u, const char *str)
{
#ifdef _LIBUFS_DEBUGGING
if (str != NULL) {
fprintf(stderr, "libufs: %s", str);
if (errno != 0)
fprintf(stderr, ": %s", strerror(errno));
fprintf(stderr, "\n");
}
#endif
if (u != NULL)
u->d_error = str;
}
#endif /* _LIBUFS */
__BEGIN_DECLS
/*
* libufs prototypes.
*/
/*
* ffs_subr.c
*/
void ffs_clrblock(struct fs *, u_char *, ufs1_daddr_t);
void ffs_clusteracct(struct fs *, struct cg *, ufs1_daddr_t, int);
void ffs_fragacct(struct fs *, int, int32_t [], int);
int ffs_isblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_isfreeblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_sbsearch(void *, struct fs **, int, char *,
int (*)(void *, off_t, void **, int));
void ffs_setblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_sbget(void *, struct fs **, off_t, int, char *,
int (*)(void *, off_t, void **, int));
int ffs_sbput(void *, struct fs *, off_t,
int (*)(void *, off_t, void *, int));
void ffs_update_dinode_ckhash(struct fs *, struct ufs2_dinode *);
int ffs_verify_dinode_ckhash(struct fs *, struct ufs2_dinode *);
/*
* block.c
*/
ssize_t bread(struct uufsd *, ufs2_daddr_t, void *, size_t);
ssize_t bwrite(struct uufsd *, ufs2_daddr_t, const void *, size_t);
int berase(struct uufsd *, ufs2_daddr_t, ufs2_daddr_t);
/*
* cgroup.c
*/
ufs2_daddr_t cgballoc(struct uufsd *);
int cgbfree(struct uufsd *, ufs2_daddr_t, long);
ino_t cgialloc(struct uufsd *);
int cgget(int, struct fs *, int, struct cg *);
int cgput(int, struct fs *, struct cg *);
int cgread(struct uufsd *);
int cgread1(struct uufsd *, int);
int cgwrite(struct uufsd *);
int cgwrite1(struct uufsd *, int);
/*
* inode.c
*/
int getinode(struct uufsd *, union dinodep *, ino_t);
int putinode(struct uufsd *);
/*
* sblock.c
*/
int sbread(struct uufsd *);
int sbfind(struct uufsd *, int);
int sbwrite(struct uufsd *, int);
/* low level superblock read/write functions */
int sbget(int, struct fs **, off_t, int);
int sbsearch(int, struct fs **, int);
int sbput(int, struct fs *, int);
/*
* type.c
*/
int ufs_disk_close(struct uufsd *);
int ufs_disk_fillout(struct uufsd *, const char *);
int ufs_disk_fillout_blank(struct uufsd *, const char *);
int ufs_disk_write(struct uufsd *);
/*
* crc32c.c
*/
uint32_t calculate_crc32c(uint32_t, const void *, size_t);
__END_DECLS
#endif /* __LIBUFS_H__ */