diff options
Diffstat (limited to 'fs/xfs/xfs_inode.c')
| -rw-r--r-- | fs/xfs/xfs_inode.c | 715 |
1 files changed, 710 insertions, 5 deletions
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 6459395a0e40..580fa0758039 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -2630,8 +2630,9 @@ xfs_idestroy_fork( ifp->if_real_bytes = 0; } } else if ((ifp->if_flags & XFS_IFEXTENTS) && - (ifp->if_u1.if_extents != NULL) && - (ifp->if_u1.if_extents != ifp->if_u2.if_inline_ext)) { + ((ifp->if_flags & XFS_IFEXTIREC) || + ((ifp->if_u1.if_extents != NULL) && + (ifp->if_u1.if_extents != ifp->if_u2.if_inline_ext)))) { ASSERT(ifp->if_real_bytes != 0); xfs_iext_destroy(ifp); } @@ -3622,7 +3623,16 @@ xfs_iext_get_ext( xfs_extnum_t idx) /* index of target extent */ { ASSERT(idx >= 0); - if (ifp->if_bytes) { + if ((ifp->if_flags & XFS_IFEXTIREC) && (idx == 0)) { + return ifp->if_u1.if_ext_irec->er_extbuf; + } else if (ifp->if_flags & XFS_IFEXTIREC) { + xfs_ext_irec_t *erp; /* irec pointer */ + int erp_idx = 0; /* irec index */ + xfs_extnum_t page_idx = idx; /* ext index in target list */ + + erp = xfs_iext_idx_to_irec(ifp, &page_idx, &erp_idx, 0); + return &erp->er_extbuf[page_idx]; + } else if (ifp->if_bytes) { return &ifp->if_u1.if_extents[idx]; } else { return NULL; @@ -3691,6 +3701,7 @@ xfs_iext_add( } ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext; ifp->if_real_bytes = 0; + ifp->if_lastex = nextents + ext_diff; } /* * Otherwise use a linear (direct) extent list. @@ -3698,7 +3709,7 @@ xfs_iext_add( * xfs_iext_realloc_direct will switch us from * inline to direct extent allocation mode. */ - else { + else if (nextents + ext_diff <= XFS_LINEAR_EXTS) { xfs_iext_realloc_direct(ifp, new_size); if (idx < nextents) { memmove(&ifp->if_u1.if_extents[idx + ext_diff], @@ -3707,14 +3718,182 @@ xfs_iext_add( memset(&ifp->if_u1.if_extents[idx], 0, byte_diff); } } + /* Indirection array */ + else { + xfs_ext_irec_t *erp; + int erp_idx = 0; + int page_idx = idx; + + ASSERT(nextents + ext_diff > XFS_LINEAR_EXTS); + if (ifp->if_flags & XFS_IFEXTIREC) { + erp = xfs_iext_idx_to_irec(ifp, &page_idx, &erp_idx, 1); + } else { + xfs_iext_irec_init(ifp); + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + erp = ifp->if_u1.if_ext_irec; + } + /* Extents fit in target extent page */ + if (erp && erp->er_extcount + ext_diff <= XFS_LINEAR_EXTS) { + if (page_idx < erp->er_extcount) { + memmove(&erp->er_extbuf[page_idx + ext_diff], + &erp->er_extbuf[page_idx], + (erp->er_extcount - page_idx) * + sizeof(xfs_bmbt_rec_t)); + memset(&erp->er_extbuf[page_idx], 0, byte_diff); + } + erp->er_extcount += ext_diff; + xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff); + } + /* Insert a new extent page */ + else if (erp) { + xfs_iext_add_indirect_multi(ifp, + erp_idx, page_idx, ext_diff); + } + /* + * If extent(s) are being appended to the last page in + * the indirection array and the new extent(s) don't fit + * in the page, then erp is NULL and erp_idx is set to + * the next index needed in the indirection array. + */ + else { + int count = ext_diff; + + while (count) { + erp = xfs_iext_irec_new(ifp, erp_idx); + erp->er_extcount = count; + count -= MIN(count, (int)XFS_LINEAR_EXTS); + if (count) { + erp_idx++; + } + } + } + } ifp->if_bytes = new_size; } /* + * This is called when incore extents are being added to the indirection + * array and the new extents do not fit in the target extent list. The + * erp_idx parameter contains the irec index for the target extent list + * in the indirection array, and the idx parameter contains the extent + * index within the list. The number of extents being added is stored + * in the count parameter. + * + * |-------| |-------| + * | | | | idx - number of extents before idx + * | idx | | count | + * | | | | count - number of extents being inserted at idx + * |-------| |-------| + * | count | | nex2 | nex2 - number of extents after idx + count + * |-------| |-------| + */ +void +xfs_iext_add_indirect_multi( + xfs_ifork_t *ifp, /* inode fork pointer */ + int erp_idx, /* target extent irec index */ + xfs_extnum_t idx, /* index within target list */ + int count) /* new extents being added */ +{ + int byte_diff; /* new bytes being added */ + xfs_ext_irec_t *erp; /* pointer to irec entry */ + xfs_extnum_t ext_diff; /* number of extents to add */ + xfs_extnum_t ext_cnt; /* new extents still needed */ + xfs_extnum_t nex2; /* extents after idx + count */ + xfs_bmbt_rec_t *nex2_ep = NULL; /* temp list for nex2 extents */ + int nlists; /* number of irec's (lists) */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + nex2 = erp->er_extcount - idx; + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + + /* + * Save second part of target extent list + * (all extents past */ + if (nex2) { + byte_diff = nex2 * sizeof(xfs_bmbt_rec_t); + nex2_ep = (xfs_bmbt_rec_t *) kmem_alloc(byte_diff, KM_SLEEP); + memmove(nex2_ep, &erp->er_extbuf[idx], byte_diff); + erp->er_extcount -= nex2; + xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, -nex2); + memset(&erp->er_extbuf[idx], 0, byte_diff); + } + + /* + * Add the new extents to the end of the target + * list, then allocate new irec record(s) and + * extent buffer(s) as needed to store the rest + * of the new extents. + */ + ext_cnt = count; + ext_diff = MIN(ext_cnt, (int)XFS_LINEAR_EXTS - erp->er_extcount); + if (ext_diff) { + erp->er_extcount += ext_diff; + xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff); + ext_cnt -= ext_diff; + } + while (ext_cnt) { + erp_idx++; + erp = xfs_iext_irec_new(ifp, erp_idx); + ext_diff = MIN(ext_cnt, (int)XFS_LINEAR_EXTS); + erp->er_extcount = ext_diff; + xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff); + ext_cnt -= ext_diff; + } + + /* Add nex2 extents back to indirection array */ + if (nex2) { + xfs_extnum_t ext_avail; + int i; + + byte_diff = nex2 * sizeof(xfs_bmbt_rec_t); + ext_avail = XFS_LINEAR_EXTS - erp->er_extcount; + i = 0; + /* + * If nex2 extents fit in the current page, append + * nex2_ep after the new extents. + */ + if (nex2 <= ext_avail) { + i = erp->er_extcount; + } + /* + * Otherwise, check if space is available in the + * next page. + */ + else if ((erp_idx < nlists - 1) && + (nex2 <= (ext_avail = XFS_LINEAR_EXTS - + ifp->if_u1.if_ext_irec[erp_idx+1].er_extcount))) { + erp_idx++; + erp++; + /* Create a hole for nex2 extents */ + memmove(&erp->er_extbuf[nex2], erp->er_extbuf, + erp->er_extcount * sizeof(xfs_bmbt_rec_t)); + } + /* + * Final choice, create a new extent page for + * nex2 extents. + */ + else { + erp_idx++; + erp = xfs_iext_irec_new(ifp, erp_idx); + } + memmove(&erp->er_extbuf[i], nex2_ep, byte_diff); + kmem_free(nex2_ep, byte_diff); + erp->er_extcount += nex2; + xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, nex2); + } +} + +/* * This is called when the amount of space required for incore file * extents needs to be decreased. The ext_diff parameter stores the * number of extents to be removed and the idx parameter contains * the extent index where the extents will be removed from. + * + * If the amount of space needed has decreased below the linear + * limit, XFS_IEXT_BUFSZ, then switch to using the contiguous + * extent array. Otherwise, use kmem_realloc() to adjust the + * size to what is needed. */ void xfs_iext_remove( @@ -3731,6 +3910,8 @@ xfs_iext_remove( if (new_size == 0) { xfs_iext_destroy(ifp); + } else if (ifp->if_flags & XFS_IFEXTIREC) { + xfs_iext_remove_indirect(ifp, idx, ext_diff); } else if (ifp->if_real_bytes) { xfs_iext_remove_direct(ifp, idx, ext_diff); } else { @@ -3751,6 +3932,7 @@ xfs_iext_remove_inline( { int nextents; /* number of extents in file */ + ASSERT(!(ifp->if_flags & XFS_IFEXTIREC)); ASSERT(idx < XFS_INLINE_EXTS); nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); ASSERT(((nextents - ext_diff) > 0) && @@ -3788,6 +3970,7 @@ xfs_iext_remove_direct( xfs_extnum_t nextents; /* number of extents in file */ int new_size; /* size of extents after removal */ + ASSERT(!(ifp->if_flags & XFS_IFEXTIREC)); new_size = ifp->if_bytes - (ext_diff * sizeof(xfs_bmbt_rec_t)); nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); @@ -3816,6 +3999,84 @@ xfs_iext_remove_direct( } /* + * This is called when incore extents are being removed from the + * indirection array and the extents being removed span multiple extent + * buffers. The idx parameter contains the file extent index where we + * want to begin removing extents, and the count parameter contains + * how many extents need to be removed. + * + * |-------| |-------| + * | nex1 | | | nex1 - number of extents before idx + * |-------| | count | + * | | | | count - number of extents being removed at idx + * | count | |-------| + * | | | nex2 | nex2 - number of extents after idx + count + * |-------| |-------| + */ +void +xfs_iext_remove_indirect( + xfs_ifork_t *ifp, /* inode fork pointer */ + xfs_extnum_t idx, /* index to begin removing extents */ + int count) /* number of extents to remove */ +{ + xfs_ext_irec_t *erp; /* indirection array pointer */ + int erp_idx = 0; /* indirection array index */ + xfs_extnum_t ext_cnt; /* extents left to remove */ + xfs_extnum_t ext_diff; /* extents to remove in current list */ + xfs_extnum_t nex1; /* number of extents before idx */ + xfs_extnum_t nex2; /* extents after idx + count */ + int nlists; /* entries in indirecton array */ + int page_idx = idx; /* index in target extent list */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + erp = xfs_iext_idx_to_irec(ifp, &page_idx, &erp_idx, 0); + ASSERT(erp != NULL); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + nex1 = page_idx; + ext_cnt = count; + while (ext_cnt) { + nex2 = MAX((erp->er_extcount - (nex1 + ext_cnt)), 0); + ext_diff = MIN(ext_cnt, (erp->er_extcount - nex1)); + /* + * Check for deletion of entire list; + * xfs_iext_irec_remove() updates extent offsets. + */ + if (ext_diff == erp->er_extcount) { + xfs_iext_irec_remove(ifp, erp_idx); + ext_cnt -= ext_diff; + nex1 = 0; + if (ext_cnt) { + ASSERT(erp_idx < ifp->if_real_bytes / + XFS_IEXT_BUFSZ); + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + nex1 = 0; + continue; + } else { + break; + } + } + /* Move extents up (if needed) */ + if (nex2) { + memmove(&erp->er_extbuf[nex1], + &erp->er_extbuf[nex1 + ext_diff], + nex2 * sizeof(xfs_bmbt_rec_t)); + } + /* Zero out rest of page */ + memset(&erp->er_extbuf[nex1 + nex2], 0, (XFS_IEXT_BUFSZ - + ((nex1 + nex2) * sizeof(xfs_bmbt_rec_t)))); + /* Update remaining counters */ + erp->er_extcount -= ext_diff; + xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, -ext_diff); + ext_cnt -= ext_diff; + nex1 = 0; + erp_idx++; + erp++; + } + ifp->if_bytes -= count * sizeof(xfs_bmbt_rec_t); + xfs_iext_irec_compact(ifp); +} + +/* * Create, destroy, or resize a linear (direct) block of extents. */ void @@ -3827,6 +4088,10 @@ xfs_iext_realloc_direct( rnew_size = new_size; + ASSERT(!(ifp->if_flags & XFS_IFEXTIREC) || + ((new_size >= 0) && (new_size <= XFS_IEXT_BUFSZ) && + (new_size != ifp->if_real_bytes))); + /* Free extent records */ if (new_size == 0) { xfs_iext_destroy(ifp); @@ -3920,13 +4185,76 @@ xfs_iext_inline_to_direct( } /* + * Resize an extent indirection array to new_size bytes. + */ +void +xfs_iext_realloc_indirect( + xfs_ifork_t *ifp, /* inode fork pointer */ + int new_size) /* new indirection array size */ +{ + int nlists; /* number of irec's (ex lists) */ + int size; /* current indirection array size */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + size = nlists * sizeof(xfs_ext_irec_t); + ASSERT(ifp->if_real_bytes); + ASSERT((new_size >= 0) && (new_size != size)); + if (new_size == 0) { + xfs_iext_destroy(ifp); + } else { + ifp->if_u1.if_ext_irec = (xfs_ext_irec_t *) + kmem_realloc(ifp->if_u1.if_ext_irec, + new_size, size, KM_SLEEP); + } +} + +/* + * Switch from indirection array to linear (direct) extent allocations. + */ +void +xfs_iext_indirect_to_direct( + xfs_ifork_t *ifp) /* inode fork pointer */ +{ + xfs_bmbt_rec_t *ep; /* extent record pointer */ + xfs_extnum_t nextents; /* number of extents in file */ + int size; /* size of file extents */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); + ASSERT(nextents <= XFS_LINEAR_EXTS); + size = nextents * sizeof(xfs_bmbt_rec_t); + + xfs_iext_irec_compact_full(ifp); + ASSERT(ifp->if_real_bytes == XFS_IEXT_BUFSZ); + + ep = ifp->if_u1.if_ext_irec->er_extbuf; + kmem_free(ifp->if_u1.if_ext_irec, sizeof(xfs_ext_irec_t)); + ifp->if_flags &= ~XFS_IFEXTIREC; + ifp->if_u1.if_extents = ep; + ifp->if_bytes = size; + if (nextents < XFS_LINEAR_EXTS) { + xfs_iext_realloc_direct(ifp, size); + } +} + +/* * Free incore file extents. */ void xfs_iext_destroy( xfs_ifork_t *ifp) /* inode fork pointer */ { - if (ifp->if_real_bytes) { + if (ifp->if_flags & XFS_IFEXTIREC) { + int erp_idx; + int nlists; + + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + for (erp_idx = nlists - 1; erp_idx >= 0 ; erp_idx--) { + xfs_iext_irec_remove(ifp, erp_idx); + } + ifp->if_flags &= ~XFS_IFEXTIREC; + } else if (ifp->if_real_bytes) { kmem_free(ifp->if_u1.if_extents, ifp->if_real_bytes); } else if (ifp->if_bytes) { memset(ifp->if_u2.if_inline_ext, 0, XFS_INLINE_EXTS * @@ -3936,3 +4264,380 @@ xfs_iext_destroy( ifp->if_real_bytes = 0; ifp->if_bytes = 0; } + +/* + * 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_iext_bno_to_irec( + xfs_ifork_t *ifp, /* inode fork pointer */ + xfs_fileoff_t bno, /* block number to search for */ + int *erp_idxp) /* irec index of target ext list */ +{ + 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 nlists; /* number of extent irec's (lists) */ + int high; /* binary search upper limit */ + int low; /* binary search lower limit */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + erp_idx = 0; + low = 0; + high = nlists - 1; + while (low <= high) { + erp_idx = (low + high) >> 1; + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + erp_next = erp_idx < nlists - 1 ? erp + 1 : NULL; + if (bno < xfs_bmbt_get_startoff(erp->er_extbuf)) { + high = erp_idx - 1; + } else if (erp_next && bno >= + xfs_bmbt_get_startoff(erp_next->er_extbuf)) { + low = erp_idx + 1; + } else { + break; + } + } + *erp_idxp = erp_idx; + return erp; +} + +/* + * Return a pointer to the indirection array entry containing the + * extent record at file extent index *idxp. Store the index of the + * target irec in *erp_idxp and store the page index of the target + * extent record in *idxp. + */ +xfs_ext_irec_t * +xfs_iext_idx_to_irec( + xfs_ifork_t *ifp, /* inode fork pointer */ + xfs_extnum_t *idxp, /* extent index (file -> page) */ + int *erp_idxp, /* pointer to target irec */ + int realloc) /* new bytes were just added */ +{ + xfs_ext_irec_t *prev; /* pointer to previous irec */ + xfs_ext_irec_t *erp = NULL; /* pointer to current irec */ + int erp_idx; /* indirection array index */ + int nlists; /* number of irec's (ex lists) */ + int high; /* binary search upper limit */ + int low; /* binary search lower limit */ + xfs_extnum_t page_idx = *idxp; /* extent index in target list */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + ASSERT(page_idx >= 0 && page_idx <= + ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t)); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + erp_idx = 0; + low = 0; + high = nlists - 1; + + /* Binary search extent irec's */ + while (low <= high) { + erp_idx = (low + high) >> 1; + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + prev = erp_idx > 0 ? erp - 1 : NULL; + if (page_idx < erp->er_extoff || (page_idx == erp->er_extoff && + realloc && prev && prev->er_extcount < XFS_LINEAR_EXTS)) { + high = erp_idx - 1; + } else if (page_idx > erp->er_extoff + erp->er_extcount || + (page_idx == erp->er_extoff + erp->er_extcount && + !realloc)) { + low = erp_idx + 1; + } else if (page_idx == erp->er_extoff + erp->er_extcount && + erp->er_extcount == XFS_LINEAR_EXTS) { + ASSERT(realloc); + page_idx = 0; + erp_idx++; + erp = erp_idx < nlists ? erp + 1 : NULL; + break; + } else { + page_idx -= erp->er_extoff; + break; + } + } + *idxp = page_idx; + *erp_idxp = erp_idx; + return(erp); +} + +/* + * Allocate and initialize an indirection array once the space needed + * for incore extents increases above XFS_IEXT_BUFSZ. + */ +void +xfs_iext_irec_init( + xfs_ifork_t *ifp) /* inode fork pointer */ +{ + xfs_ext_irec_t *erp; /* indirection array pointer */ + xfs_extnum_t nextents; /* number of extents in file */ + + ASSERT(!(ifp->if_flags & XFS_IFEXTIREC)); + nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); + ASSERT(nextents <= XFS_LINEAR_EXTS); + + erp = (xfs_ext_irec_t *) + kmem_alloc(sizeof(xfs_ext_irec_t), KM_SLEEP); + + if (nextents == 0) { + ifp->if_u1.if_extents = (xfs_bmbt_rec_t *) + kmem_alloc(XFS_IEXT_BUFSZ, KM_SLEEP); + } else if (!ifp->if_real_bytes) { + xfs_iext_inline_to_direct(ifp, XFS_IEXT_BUFSZ); + } else if (ifp->if_real_bytes < XFS_IEXT_BUFSZ) { + xfs_iext_realloc_direct(ifp, XFS_IEXT_BUFSZ); + } + erp->er_extbuf = ifp->if_u1.if_extents; + erp->er_extcount = nextents; + erp->er_extoff = 0; + + ifp->if_flags |= XFS_IFEXTIREC; + ifp->if_real_bytes = XFS_IEXT_BUFSZ; + ifp->if_bytes = nextents * sizeof(xfs_bmbt_rec_t); + ifp->if_u1.if_ext_irec = erp; + + return; +} + +/* + * Allocate and initialize a new entry in the indirection array. + */ +xfs_ext_irec_t * +xfs_iext_irec_new( + xfs_ifork_t *ifp, /* inode fork pointer */ + int erp_idx) /* index for new irec */ +{ + xfs_ext_irec_t *erp; /* indirection array pointer */ + int i; /* loop counter */ + int nlists; /* number of irec's (ex lists) */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + + /* Resize indirection array */ + xfs_iext_realloc_indirect(ifp, ++nlists * + sizeof(xfs_ext_irec_t)); + /* + * Move records down in the array so the + * new page can use erp_idx. + */ + erp = ifp->if_u1.if_ext_irec; + for (i = nlists - 1; i > erp_idx; i--) { + memmove(&erp[i], &erp[i-1], sizeof(xfs_ext_irec_t)); + } + ASSERT(i == erp_idx); + + /* Initialize new extent record */ + erp = ifp->if_u1.if_ext_irec; + erp[erp_idx].er_extbuf = (xfs_bmbt_rec_t *) + kmem_alloc(XFS_IEXT_BUFSZ, KM_SLEEP); + ifp->if_real_bytes = nlists * XFS_IEXT_BUFSZ; + memset(erp[erp_idx].er_extbuf, 0, XFS_IEXT_BUFSZ); + erp[erp_idx].er_extcount = 0; + erp[erp_idx].er_extoff = erp_idx > 0 ? + erp[erp_idx-1].er_extoff + erp[erp_idx-1].er_extcount : 0; + return (&erp[erp_idx]); +} + +/* + * Remove a record from the indirection array. + */ +void +xfs_iext_irec_remove( + xfs_ifork_t *ifp, /* inode fork pointer */ + int erp_idx) /* irec index to remove */ +{ + xfs_ext_irec_t *erp; /* indirection array pointer */ + int i; /* loop counter */ + int nlists; /* number of irec's (ex lists) */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + if (erp->er_extbuf) { + xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, + -erp->er_extcount); + kmem_free(erp->er_extbuf, XFS_IEXT_BUFSZ); + } + /* Compact extent records */ + erp = ifp->if_u1.if_ext_irec; + for (i = erp_idx; i < nlists - 1; i++) { + memmove(&erp[i], &erp[i+1], sizeof(xfs_ext_irec_t)); + } + /* + * Manually free the last extent record from the indirection + * array. A call to xfs_iext_realloc_indirect() with a size + * of zero would result in a call to xfs_iext_destroy() which + * would in turn call this function again, creating a nasty + * infinite loop. + */ + if (--nlists) { + xfs_iext_realloc_indirect(ifp, + nlists * sizeof(xfs_ext_irec_t)); + } else { + kmem_free(ifp->if_u1.if_ext_irec, + sizeof(xfs_ext_irec_t)); + } + ifp->if_real_bytes = nlists * XFS_IEXT_BUFSZ; +} + +/* + * This is called to clean up large amounts of unused memory allocated + * by the indirection array. Before compacting anything though, verify + * that the indirection array is still needed and switch back to the + * linear extent list (or even the inline buffer) if possible. The + * compaction policy is as follows: + * + * Full Compaction: Extents fit into a single page (or inline buffer) + * Full Compaction: Extents occupy less than 10% of allocated space + * Partial Compaction: Extents occupy > 10% and < 50% of allocated space + * No Compaction: Extents occupy at least 50% of allocated space + */ +void +xfs_iext_irec_compact( + xfs_ifork_t *ifp) /* inode fork pointer */ +{ + xfs_extnum_t nextents; /* number of extents in file */ + int nlists; /* number of irec's (ex lists) */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t); + + if (nextents == 0) { + xfs_iext_destroy(ifp); + } else if (nextents <= XFS_INLINE_EXTS) { + xfs_iext_indirect_to_direct(ifp); + xfs_iext_direct_to_inline(ifp, nextents); + } else if (nextents <= XFS_LINEAR_EXTS) { + xfs_iext_indirect_to_direct(ifp); + } else if (nextents < (nlists * XFS_LINEAR_EXTS) >> 3) { + xfs_iext_irec_compact_full(ifp); + } else if (nextents < (nlists * XFS_LINEAR_EXTS) >> 1) { + xfs_iext_irec_compact_pages(ifp); + } +} + +/* + * Combine extents from neighboring extent pages. + */ +void +xfs_iext_irec_compact_pages( + xfs_ifork_t *ifp) /* inode fork pointer */ +{ + xfs_ext_irec_t *erp, *erp_next;/* pointers to irec entries */ + int erp_idx = 0; /* indirection array index */ + int nlists; /* number of irec's (ex lists) */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + while (erp_idx < nlists - 1) { + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + erp_next = erp + 1; + if (erp_next->er_extcount <= + (XFS_LINEAR_EXTS - erp->er_extcount)) { + memmove(&erp->er_extbuf[erp->er_extcount], + erp_next->er_extbuf, erp_next->er_extcount * + sizeof(xfs_bmbt_rec_t)); + erp->er_extcount += erp_next->er_extcount; + /* + * Free page before removing extent record + * so er_extoffs don't get modified in + * xfs_iext_irec_remove. + */ + kmem_free(erp_next->er_extbuf, XFS_IEXT_BUFSZ); + erp_next->er_extbuf = NULL; + xfs_iext_irec_remove(ifp, erp_idx + 1); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + } else { + erp_idx++; + } + } +} + +/* + * Fully compact the extent records managed by the indirection array. + */ +void +xfs_iext_irec_compact_full( + xfs_ifork_t *ifp) /* inode fork pointer */ +{ + xfs_bmbt_rec_t *ep, *ep_next; /* extent record pointers */ + xfs_ext_irec_t *erp, *erp_next; /* extent irec pointers */ + int erp_idx = 0; /* extent irec index */ + int ext_avail; /* empty entries in ex list */ + int ext_diff; /* number of exts to add */ + int nlists; /* number of irec's (ex lists) */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + erp = ifp->if_u1.if_ext_irec; + ep = &erp->er_extbuf[erp->er_extcount]; + erp_next = erp + 1; + ep_next = erp_next->er_extbuf; + while (erp_idx < nlists - 1) { + ext_avail = XFS_LINEAR_EXTS - erp->er_extcount; + ext_diff = MIN(ext_avail, erp_next->er_extcount); + memcpy(ep, ep_next, ext_diff * sizeof(xfs_bmbt_rec_t)); + erp->er_extcount += ext_diff; + erp_next->er_extcount -= ext_diff; + /* Remove next page */ + if (erp_next->er_extcount == 0) { + /* + * Free page before removing extent record + * so er_extoffs don't get modified in + * xfs_iext_irec_remove. + */ + kmem_free(erp_next->er_extbuf, + erp_next->er_extcount * sizeof(xfs_bmbt_rec_t)); + erp_next->er_extbuf = NULL; + xfs_iext_irec_remove(ifp, erp_idx + 1); + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + /* Update next page */ + } else { + /* Move rest of page up to become next new page */ + memmove(erp_next->er_extbuf, ep_next, + erp_next->er_extcount * sizeof(xfs_bmbt_rec_t)); + ep_next = erp_next->er_extbuf; + memset(&ep_next[erp_next->er_extcount], 0, + (XFS_LINEAR_EXTS - erp_next->er_extcount) * + sizeof(xfs_bmbt_rec_t)); + } + if (erp->er_extcount == XFS_LINEAR_EXTS) { + erp_idx++; + if (erp_idx < nlists) + erp = &ifp->if_u1.if_ext_irec[erp_idx]; + else + break; + } + ep = &erp->er_extbuf[erp->er_extcount]; + erp_next = erp + 1; + ep_next = erp_next->er_extbuf; + } +} + +/* + * This is called to update the er_extoff field in the indirection + * array when extents have been added or removed from one of the + * extent lists. erp_idx contains the irec index to begin updating + * at and ext_diff contains the number of extents that were added + * or removed. + */ +void +xfs_iext_irec_update_extoffs( + xfs_ifork_t *ifp, /* inode fork pointer */ + int erp_idx, /* irec index to update */ + int ext_diff) /* number of new extents */ +{ + int i; /* loop counter */ + int nlists; /* number of irec's (ex lists */ + + ASSERT(ifp->if_flags & XFS_IFEXTIREC); + nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ; + for (i = erp_idx; i < nlists; i++) { + ifp->if_u1.if_ext_irec[i].er_extoff += ext_diff; + } +} |
