diff options
Diffstat (limited to 'fs/xfs/xfs_inode.c')
| -rw-r--r-- | fs/xfs/xfs_inode.c | 73 |
1 files changed, 71 insertions, 2 deletions
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 580fa075803..a16df2d435f 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -4266,11 +4266,80 @@ xfs_iext_destroy( } /* + * Return a pointer to the extent record for file system block bno. + */ +xfs_bmbt_rec_t * /* pointer to found extent record */ +xfs_iext_bno_to_ext( + xfs_ifork_t *ifp, /* inode fork pointer */ + xfs_fileoff_t bno, /* block number to search for */ + xfs_extnum_t *idxp) /* index of target extent */ +{ + xfs_bmbt_rec_t *base; /* pointer to first extent */ + xfs_filblks_t blockcount = 0; /* number of blocks in extent */ + xfs_bmbt_rec_t *ep = NULL; /* pointer to target extent */ + xfs_ext_irec_t *erp = NULL; /* indirection array pointer */ + int high; /* upper boundry in search */ + xfs_extnum_t idx = 0; /* index of target extent */ + int low; /* lower boundry in search */ + xfs_extnum_t nextents; /* number of file extents */ + xfs_fileoff_t startoff = 0; /* start offset of extent */ + + nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); + if (nextents == 0) { + *idxp = 0; + return NULL; + } + low = 0; + if (ifp->if_flags & XFS_IFEXTIREC) { + /* Find target extent list */ + int erp_idx = 0; + erp = xfs_iext_bno_to_irec(ifp, bno, &erp_idx); + base = erp->er_extbuf; + high = erp->er_extcount - 1; + } else { + base = ifp->if_u1.if_extents; + high = nextents - 1; + } + /* Binary search extent records */ + while (low <= high) { + idx = (low + high) >> 1; + ep = base + idx; + startoff = xfs_bmbt_get_startoff(ep); + blockcount = xfs_bmbt_get_blockcount(ep); + if (bno < startoff) { + high = idx - 1; + } else if (bno >= startoff + blockcount) { + low = idx + 1; + } else { + /* Convert back to file-based extent index */ + if (ifp->if_flags & XFS_IFEXTIREC) { + idx += erp->er_extoff; + } + *idxp = idx; + return ep; + } + } + /* Convert back to file-based extent index */ + if (ifp->if_flags & XFS_IFEXTIREC) { + idx += erp->er_extoff; + } + if (bno >= startoff + blockcount) { + if (++idx == nextents) { + ep = NULL; + } else { + ep = xfs_iext_get_ext(ifp, idx); + } + } + *idxp = idx; + return ep; +} + +/* * Return a pointer to the indirection array entry containing the * extent record for filesystem block bno. Store the index of the * target irec in *erp_idxp. */ -xfs_ext_irec_t * +xfs_ext_irec_t * /* pointer to found extent record */ xfs_iext_bno_to_irec( xfs_ifork_t *ifp, /* inode fork pointer */ xfs_fileoff_t bno, /* block number to search for */ @@ -4278,7 +4347,7 @@ xfs_iext_bno_to_irec( { xfs_ext_irec_t *erp = NULL; /* indirection array pointer */ xfs_ext_irec_t *erp_next; /* next indirection array entry */ - xfs_extnum_t erp_idx; /* indirection array index */ + int erp_idx; /* indirection array index */ int nlists; /* number of extent irec's (lists) */ int high; /* binary search upper limit */ int low; /* binary search lower limit */ |