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);
}
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;
}
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.
* 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],
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(
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 {
{
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) &&
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);
ifp->if_bytes = new_size;
}
+/*
+ * 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.
*/
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);
ifp->if_real_bytes = new_size;
}
+/*
+ * 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.
*/
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 *
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;
+ }
+}
projects / linux-2.6-omap-h63xx.git / commitdiff