libfrog/fsgeom.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.  All Rights Reserved.
   4  */
   5 #ifndef __LIBFROG_FSGEOM_H__
   6 #define __LIBFROG_FSGEOM_H__
   7
   8 void xfs_report_geom(struct xfs_fsop_geom *geo, const char *mntpoint,
   9                 const char *logname, const char *rtname);
  10 int xfrog_geometry(int fd, struct xfs_fsop_geom *fsgeo);
  11
  12 /*
  13  * Structure for recording whatever observations we want about the level of
  14  * xfs runtime support for this fd.  Right now we only store the fd and fs
  15  * geometry.
  16  */
  17 struct xfs_fd {
  18         /* ioctl file descriptor */
  19         int                     fd;
  20
  21         /* filesystem geometry */
  22         struct xfs_fsop_geom    fsgeom;
  23
  24         /* log2 of sb_agblocks (rounded up) */
  25         unsigned int            agblklog;
  26
  27         /* log2 of sb_blocksize */
  28         unsigned int            blocklog;
  29
  30         /* log2 of sb_inodesize */
  31         unsigned int            inodelog;
  32
  33         /* log2 of sb_inopblock */
  34         unsigned int            inopblog;
  35
  36         /* bits for agino in inum */
  37         unsigned int            aginolog;
  38 };
  39
  40 /* Static initializers */
  41 #define XFS_FD_INIT(_fd)        { .fd = (_fd), }
  42 #define XFS_FD_INIT_EMPTY       XFS_FD_INIT(-1)
  43
  44 int xfd_prepare_geometry(struct xfs_fd *xfd);
  45 int xfd_open(struct xfs_fd *xfd, const char *pathname, int flags);
  46 int xfd_close(struct xfs_fd *xfd);
  47
  48 /* Convert AG number and AG inode number into fs inode number. */
  49 static inline uint64_t
  50 cvt_agino_to_ino(
  51         const struct xfs_fd     *xfd,
  52         uint32_t                agno,
  53         uint32_t                agino)
  54 {
  55         return ((uint64_t)agno << xfd->aginolog) + agino;
  56 }
  57
  58 /* Convert fs inode number into AG number. */
  59 static inline uint32_t
  60 cvt_ino_to_agno(
  61         const struct xfs_fd     *xfd,
  62         uint64_t                ino)
  63 {
  64         return ino >> xfd->aginolog;
  65 }
  66
  67 /* Convert fs inode number into AG inode number. */
  68 static inline uint32_t
  69 cvt_ino_to_agino(
  70         const struct xfs_fd     *xfd,
  71         uint64_t                ino)
  72 {
  73         return ino & ((1ULL << xfd->aginolog) - 1);
  74 }
  75
  76 /*
  77  * Convert a linear fs block offset number into bytes.  This is the runtime
  78  * equivalent of XFS_FSB_TO_B, which means that it is /not/ for segmented fsbno
  79  * format (= agno | agbno) that we use internally for the data device.
  80  */
  81 static inline uint64_t
  82 cvt_off_fsb_to_b(
  83         const struct xfs_fd     *xfd,
  84         uint64_t                fsb)
  85 {
  86         return fsb << xfd->blocklog;
  87 }
  88
  89 /*
  90  * Convert bytes into a (rounded down) linear fs block offset number.  This is
  91  * the runtime equivalent of XFS_B_TO_FSBT.  It does not produce segmented
  92  * fsbno numbers (= agno | agbno).
  93  */
  94 static inline uint64_t
  95 cvt_b_to_off_fsbt(
  96         const struct xfs_fd     *xfd,
  97         uint64_t                bytes)
  98 {
  99         return bytes >> xfd->blocklog;
 100 }
 101
 102 #endif /* __LIBFROG_FSGEOM_H__ */