/* * Copyright (c) 2000-2005 Silicon Graphics, Inc. * All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_types.h" #include "xfs_bit.h" #include "xfs_log.h" #include "xfs_trans.h" #include "xfs_sb.h" #include "xfs_ag.h" #include "xfs_mount.h" #include "xfs_da_btree.h" #include "xfs_bmap_btree.h" #include "xfs_dir2.h" #include "xfs_dir2_format.h" #include "xfs_dir2_priv.h" #include "xfs_dinode.h" #include "xfs_inode.h" #include "xfs_inode_item.h" #include "xfs_alloc.h" #include "xfs_bmap.h" #include "xfs_attr.h" #include "xfs_attr_leaf.h" #include "xfs_error.h" #include "xfs_trace.h" /* * xfs_da_btree.c * * Routines to implement directories as Btrees of hashed names. */ /*======================================================================== * Function prototypes for the kernel. *========================================================================*/ /* * Routines used for growing the Btree. */ STATIC int xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *existing_root, xfs_da_state_blk_t *new_child); STATIC int xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *existing_blk, xfs_da_state_blk_t *split_blk, xfs_da_state_blk_t *blk_to_add, int treelevel, int *result); STATIC void xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *node_blk_1, xfs_da_state_blk_t *node_blk_2); STATIC void xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *old_node_blk, xfs_da_state_blk_t *new_node_blk); /* * Routines used for shrinking the Btree. */ STATIC int xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk); STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval); STATIC void xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk); STATIC void xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *src_node_blk, xfs_da_state_blk_t *dst_node_blk); /* * Utility routines. */ STATIC uint xfs_da_node_lasthash(struct xfs_buf *bp, int *count); STATIC int xfs_da_node_order(struct xfs_buf *node1_bp, struct xfs_buf *node2_bp); STATIC int xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk, xfs_da_state_blk_t *save_blk); STATIC void xfs_da_state_kill_altpath(xfs_da_state_t *state); /*======================================================================== * Routines used for growing the Btree. *========================================================================*/ /* * Create the initial contents of an intermediate node. */ int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level, struct xfs_buf **bpp, int whichfork) { xfs_da_intnode_t *node; struct xfs_buf *bp; int error; xfs_trans_t *tp; trace_xfs_da_node_create(args); tp = args->trans; error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork); if (error) return(error); ASSERT(bp != NULL); node = bp->b_addr; node->hdr.info.forw = 0; node->hdr.info.back = 0; node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC); node->hdr.info.pad = 0; node->hdr.count = 0; node->hdr.level = cpu_to_be16(level); xfs_trans_log_buf(tp, bp, XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr))); *bpp = bp; return(0); } /* * Split a leaf node, rebalance, then possibly split * intermediate nodes, rebalance, etc. */ int /* error */ xfs_da_split(xfs_da_state_t *state) { xfs_da_state_blk_t *oldblk, *newblk, *addblk; xfs_da_intnode_t *node; struct xfs_buf *bp; int max, action, error, i; trace_xfs_da_split(state->args); /* * Walk back up the tree splitting/inserting/adjusting as necessary. * If we need to insert and there isn't room, split the node, then * decide which fragment to insert the new block from below into. * Note that we may split the root this way, but we need more fixup. */ max = state->path.active - 1; ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH)); ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC || state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC); addblk = &state->path.blk[max]; /* initial dummy value */ for (i = max; (i >= 0) && addblk; state->path.active--, i--) { oldblk = &state->path.blk[i]; newblk = &state->altpath.blk[i]; /* * If a leaf node then * Allocate a new leaf node, then rebalance across them. * else if an intermediate node then * We split on the last layer, must we split the node? */ switch (oldblk->magic) { case XFS_ATTR_LEAF_MAGIC: error = xfs_attr_leaf_split(state, oldblk, newblk); if ((error != 0) && (error != ENOSPC)) { return(error); /* GROT: attr is inconsistent */ } if (!error) { addblk = newblk; break; } /* * Entry wouldn't fit, split the leaf again. */ state->extravalid = 1; if (state->inleaf) { state->extraafter = 0; /* before newblk */ trace_xfs_attr_leaf_split_before(state->args); error = xfs_attr_leaf_split(state, oldblk, &state->extrablk); } else { state->extraafter = 1; /* after newblk */ trace_xfs_attr_leaf_split_after(state->args); error = xfs_attr_leaf_split(state, newblk, &state->extrablk); } if (error) return(error); /* GROT: attr inconsistent */ addblk = newblk; break; case XFS_DIR2_LEAFN_MAGIC: error = xfs_dir2_leafn_split(state, oldblk, newblk); if (error) return error; addblk = newblk; break; case XFS_DA_NODE_MAGIC: error = xfs_da_node_split(state, oldblk, newblk, addblk, max - i, &action); addblk->bp = NULL; if (error) return(error); /* GROT: dir is inconsistent */ /* * Record the newly split block for the next time thru? */ if (action) addblk = newblk; else addblk = NULL; break; } /* * Update the btree to show the new hashval for this child. */ xfs_da_fixhashpath(state, &state->path); } if (!addblk) return(0); /* * Split the root node. */ ASSERT(state->path.active == 0); oldblk = &state->path.blk[0]; error = xfs_da_root_split(state, oldblk, addblk); if (error) { addblk->bp = NULL; return(error); /* GROT: dir is inconsistent */ } /* * Update pointers to the node which used to be block 0 and * just got bumped because of the addition of a new root node. * There might be three blocks involved if a double split occurred, * and the original block 0 could be at any position in the list. */ node = oldblk->bp->b_addr; if (node->hdr.info.forw) { if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) { bp = addblk->bp; } else { ASSERT(state->extravalid); bp = state->extrablk.bp; } node = bp->b_addr; node->hdr.info.back = cpu_to_be32(oldblk->blkno); xfs_trans_log_buf(state->args->trans, bp, XFS_DA_LOGRANGE(node, &node->hdr.info, sizeof(node->hdr.info))); } node = oldblk->bp->b_addr; if (node->hdr.info.back) { if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) { bp = addblk->bp; } else { ASSERT(state->extravalid); bp = state->extrablk.bp; } node = bp->b_addr; node->hdr.info.forw = cpu_to_be32(oldblk->blkno); xfs_trans_log_buf(state->args->trans, bp, XFS_DA_LOGRANGE(node, &node->hdr.info, sizeof(node->hdr.info))); } addblk->bp = NULL; return(0); } /* * Split the root. We have to create a new root and point to the two * parts (the split old root) that we just created. Copy block zero to * the EOF, extending the inode in process. */ STATIC int /* error */ xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1, xfs_da_state_blk_t *blk2) { xfs_da_intnode_t *node, *oldroot; xfs_da_args_t *args; xfs_dablk_t blkno; struct xfs_buf *bp; int error, size; xfs_inode_t *dp; xfs_trans_t *tp; xfs_mount_t *mp; xfs_dir2_leaf_t *leaf; trace_xfs_da_root_split(state->args); /* * Copy the existing (incorrect) block from the root node position * to a free space somewhere. */ args = state->args; ASSERT(args != NULL); error = xfs_da_grow_inode(args, &blkno); if (error) return(error); dp = args->dp; tp = args->trans; mp = state->mp; error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork); if (error) return(error); ASSERT(bp != NULL); node = bp->b_addr; oldroot = blk1->bp->b_addr; if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)) { size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] - (char *)oldroot); } else { ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)); leaf = (xfs_dir2_leaf_t *)oldroot; size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] - (char *)leaf); } memcpy(node, oldroot, size); xfs_trans_log_buf(tp, bp, 0, size - 1); blk1->bp = bp; blk1->blkno = blkno; /* * Set up the new root node. */ error = xfs_da_node_create(args, (args->whichfork == XFS_DATA_FORK) ? mp->m_dirleafblk : 0, be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork); if (error) return(error); node = bp->b_addr; node->btree[0].hashval = cpu_to_be32(blk1->hashval); node->btree[0].before = cpu_to_be32(blk1->blkno); node->btree[1].hashval = cpu_to_be32(blk2->hashval); node->btree[1].before = cpu_to_be32(blk2->blkno); node->hdr.count = cpu_to_be16(2); #ifdef DEBUG if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) { ASSERT(blk1->blkno >= mp->m_dirleafblk && blk1->blkno < mp->m_dirfreeblk); ASSERT(blk2->blkno >= mp->m_dirleafblk && blk2->blkno < mp->m_dirfreeblk); } #endif /* Header is already logged by xfs_da_node_create */ xfs_trans_log_buf(tp, bp, XFS_DA_LOGRANGE(node, node->btree, sizeof(xfs_da_node_entry_t) * 2)); return(0); } /* * Split the node, rebalance, then add the new entry. */ STATIC int /* error */ xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk, xfs_da_state_blk_t *newblk, xfs_da_state_blk_t *addblk, int treelevel, int *result) { xfs_da_intnode_t *node; xfs_dablk_t blkno; int newcount, error; int useextra; trace_xfs_da_node_split(state->args); node = oldblk->bp->b_addr; ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); /* * With V2 dirs the extra block is data or freespace. */ useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK; newcount = 1 + useextra; /* * Do we have to split the node? */ if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) { /* * Allocate a new node, add to the doubly linked chain of * nodes, then move some of our excess entries into it. */ error = xfs_da_grow_inode(state->args, &blkno); if (error) return(error); /* GROT: dir is inconsistent */ error = xfs_da_node_create(state->args, blkno, treelevel, &newblk->bp, state->args->whichfork); if (error) return(error); /* GROT: dir is inconsistent */ newblk->blkno = blkno; newblk->magic = XFS_DA_NODE_MAGIC; xfs_da_node_rebalance(state, oldblk, newblk); error = xfs_da_blk_link(state, oldblk, newblk); if (error) return(error); *result = 1; } else { *result = 0; } /* * Insert the new entry(s) into the correct block * (updating last hashval in the process). * * xfs_da_node_add() inserts BEFORE the given index, * and as a result of using node_lookup_int() we always * point to a valid entry (not after one), but a split * operation always results in a new block whose hashvals * FOLLOW the current block. * * If we had double-split op below us, then add the extra block too. */ node = oldblk->bp->b_addr; if (oldblk->index <= be16_to_cpu(node->hdr.count)) { oldblk->index++; xfs_da_node_add(state, oldblk, addblk); if (useextra) { if (state->extraafter) oldblk->index++; xfs_da_node_add(state, oldblk, &state->extrablk); state->extravalid = 0; } } else { newblk->index++; xfs_da_node_add(state, newblk, addblk); if (useextra) { if (state->extraafter) newblk->index++; xfs_da_node_add(state, newblk, &state->extrablk); state->extravalid = 0; } } return(0); } /* * Balance the btree elements between two intermediate nodes, * usually one full and one empty. * * NOTE: if blk2 is empty, then it will get the upper half of blk1. */ STATIC void xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1, xfs_da_state_blk_t *blk2) { xfs_da_intnode_t *node1, *node2, *tmpnode; xfs_da_node_entry_t *btree_s, *btree_d; int count, tmp; xfs_trans_t *tp; trace_xfs_da_node_rebalance(state->args); node1 = blk1->bp->b_addr; node2 = blk2->bp->b_addr; /* * Figure out how many entries need to move, and in which direction. * Swap the nodes around if that makes it simpler. */ if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) && ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) || (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) < be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) { tmpnode = node1; node1 = node2; node2 = tmpnode; } ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); ASSERT(node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2; if (count == 0) return; tp = state->args->trans; /* * Two cases: high-to-low and low-to-high. */ if (count > 0) { /* * Move elements in node2 up to make a hole. */ if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) { tmp *= (uint)sizeof(xfs_da_node_entry_t); btree_s = &node2->btree[0]; btree_d = &node2->btree[count]; memmove(btree_d, btree_s, tmp); } /* * Move the req'd B-tree elements from high in node1 to * low in node2. */ be16_add_cpu(&node2->hdr.count, count); tmp = count * (uint)sizeof(xfs_da_node_entry_t); btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count]; btree_d = &node2->btree[0]; memcpy(btree_d, btree_s, tmp); be16_add_cpu(&node1->hdr.count, -count); } else { /* * Move the req'd B-tree elements from low in node2 to * high in node1. */ count = -count; tmp = count * (uint)sizeof(xfs_da_node_entry_t); btree_s = &node2->btree[0]; btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)]; memcpy(btree_d, btree_s, tmp); be16_add_cpu(&node1->hdr.count, count); xfs_trans_log_buf(tp, blk1->bp, XFS_DA_LOGRANGE(node1, btree_d, tmp)); /* * Move elements in node2 down to fill the hole. */ tmp = be16_to_cpu(node2->hdr.count) - count; tmp *= (uint)sizeof(xfs_da_node_entry_t); btree_s = &node2->btree[count]; btree_d = &node2->btree[0]; memmove(btree_d, btree_s, tmp); be16_add_cpu(&node2->hdr.count, -count); } /* * Log header of node 1 and all current bits of node 2. */ xfs_trans_log_buf(tp, blk1->bp, XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr))); xfs_trans_log_buf(tp, blk2->bp, XFS_DA_LOGRANGE(node2, &node2->hdr, sizeof(node2->hdr) + sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count))); /* * Record the last hashval from each block for upward propagation. * (note: don't use the swapped node pointers) */ node1 = blk1->bp->b_addr; node2 = blk2->bp->b_addr; blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval); blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval); /* * Adjust the expected index for insertion. */ if (blk1->index >= be16_to_cpu(node1->hdr.count)) { blk2->index = blk1->index - be16_to_cpu(node1->hdr.count); blk1->index = be16_to_cpu(node1->hdr.count) + 1; /* make it invalid */ } } /* * Add a new entry to an intermediate node. */ STATIC void xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk, xfs_da_state_blk_t *newblk) { xfs_da_intnode_t *node; xfs_da_node_entry_t *btree; int tmp; trace_xfs_da_node_add(state->args); node = oldblk->bp->b_addr; ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count))); ASSERT(newblk->blkno != 0); if (state->args->whichfork == XFS_DATA_FORK) ASSERT(newblk->blkno >= state->mp->m_dirleafblk && newblk->blkno < state->mp->m_dirfreeblk); /* * We may need to make some room before we insert the new node. */ tmp = 0; btree = &node->btree[ oldblk->index ]; if (oldblk->index < be16_to_cpu(node->hdr.count)) { tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree); memmove(btree + 1, btree, tmp); } btree->hashval = cpu_to_be32(newblk->hashval); btree->before = cpu_to_be32(newblk->blkno); xfs_trans_log_buf(state->args->trans, oldblk->bp, XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree))); be16_add_cpu(&node->hdr.count, 1); xfs_trans_log_buf(state->args->trans, oldblk->bp, XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr))); /* * Copy the last hash value from the oldblk to propagate upwards. */ oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval); } /*======================================================================== * Routines used for shrinking the Btree. *========================================================================*/ /* * Deallocate an empty leaf node, remove it from its parent, * possibly deallocating that block, etc... */ int xfs_da_join(xfs_da_state_t *state) { xfs_da_state_blk_t *drop_blk, *save_blk; int action, error; trace_xfs_da_join(state->args); action = 0; drop_blk = &state->path.blk[ state->path.active-1 ]; save_blk = &state->altpath.blk[ state->path.active-1 ]; ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC); ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC || drop_blk->magic == XFS_DIR2_LEAFN_MAGIC); /* * Walk back up the tree joining/deallocating as necessary. * When we stop dropping blocks, break out. */ for ( ; state->path.active >= 2; drop_blk--, save_blk--, state->path.active--) { /* * See if we can combine the block with a neighbor. * (action == 0) => no options, just leave * (action == 1) => coalesce, then unlink * (action == 2) => block empty, unlink it */ switch (drop_blk->magic) { case XFS_ATTR_LEAF_MAGIC: error = xfs_attr_leaf_toosmall(state, &action); if (error) return(error); if (action == 0) return(0); xfs_attr_leaf_unbalance(state, drop_blk, save_blk); break; case XFS_DIR2_LEAFN_MAGIC: error = xfs_dir2_leafn_toosmall(state, &action); if (error) return error; if (action == 0) return 0; xfs_dir2_leafn_unbalance(state, drop_blk, save_blk); break; case XFS_DA_NODE_MAGIC: /* * Remove the offending node, fixup hashvals, * check for a toosmall neighbor. */ xfs_da_node_remove(state, drop_blk); xfs_da_fixhashpath(state, &state->path); error = xfs_da_node_toosmall(state, &action); if (error) return(error); if (action == 0) return 0; xfs_da_node_unbalance(state, drop_blk, save_blk); break; } xfs_da_fixhashpath(state, &state->altpath); error = xfs_da_blk_unlink(state, drop_blk, save_blk); xfs_da_state_kill_altpath(state); if (error) return(error); error = xfs_da_shrink_inode(state->args, drop_blk->blkno, drop_blk->bp); drop_blk->bp = NULL; if (error) return(error); } /* * We joined all the way to the top. If it turns out that * we only have one entry in the root, make the child block * the new root. */ xfs_da_node_remove(state, drop_blk); xfs_da_fixhashpath(state, &state->path); error = xfs_da_root_join(state, &state->path.blk[0]); return(error); } #ifdef DEBUG static void xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level) { __be16 magic = blkinfo->magic; if (level == 1) { ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) || magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC)); } else ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); ASSERT(!blkinfo->forw); ASSERT(!blkinfo->back); } #else /* !DEBUG */ #define xfs_da_blkinfo_onlychild_validate(blkinfo, level) #endif /* !DEBUG */ /* * We have only one entry in the root. Copy the only remaining child of * the old root to block 0 as the new root node. */ STATIC int xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk) { xfs_da_intnode_t *oldroot; xfs_da_args_t *args; xfs_dablk_t child; struct xfs_buf *bp; int error; trace_xfs_da_root_join(state->args); args = state->args; ASSERT(args != NULL); ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC); oldroot = root_blk->bp->b_addr; ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); ASSERT(!oldroot->hdr.info.forw); ASSERT(!oldroot->hdr.info.back); /* * If the root has more than one child, then don't do anything. */ if (be16_to_cpu(oldroot->hdr.count) > 1) return(0); /* * Read in the (only) child block, then copy those bytes into * the root block's buffer and free the original child block. */ child = be32_to_cpu(oldroot->btree[0].before); ASSERT(child != 0); error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp, args->whichfork, NULL); if (error) return(error); ASSERT(bp != NULL); xfs_da_blkinfo_onlychild_validate(bp->b_addr, be16_to_cpu(oldroot->hdr.level)); memcpy(root_blk->bp->b_addr, bp->b_addr, state->blocksize); xfs_trans_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1); error = xfs_da_shrink_inode(args, child, bp); return(error); } /* * Check a node block and its neighbors to see if the block should be * collapsed into one or the other neighbor. Always keep the block * with the smaller block number. * If the current block is over 50% full, don't try to join it, return 0. * If the block is empty, fill in the state structure and return 2. * If it can be collapsed, fill in the state structure and return 1. * If nothing can be done, return 0. */ STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *action) { xfs_da_intnode_t *node; xfs_da_state_blk_t *blk; xfs_da_blkinfo_t *info; int count, forward, error, retval, i; xfs_dablk_t blkno; struct xfs_buf *bp; trace_xfs_da_node_toosmall(state->args); /* * Check for the degenerate case of the block being over 50% full. * If so, it's not worth even looking to see if we might be able * to coalesce with a sibling. */ blk = &state->path.blk[ state->path.active-1 ]; info = blk->bp->b_addr; ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); node = (xfs_da_intnode_t *)info; count = be16_to_cpu(node->hdr.count); if (count > (state->node_ents >> 1)) { *action = 0; /* blk over 50%, don't try to join */ return(0); /* blk over 50%, don't try to join */ } /* * Check for the degenerate case of the block being empty. * If the block is empty, we'll simply delete it, no need to * coalesce it with a sibling block. We choose (arbitrarily) * to merge with the forward block unless it is NULL. */ if (count == 0) { /* * Make altpath point to the block we want to keep and * path point to the block we want to drop (this one). */ forward = (info->forw != 0); memcpy(&state->altpath, &state->path, sizeof(state->path)); error = xfs_da_path_shift(state, &state->altpath, forward, 0, &retval); if (error) return(error); if (retval) { *action = 0; } else { *action = 2; } return(0); } /* * Examine each sibling block to see if we can coalesce with * at least 25% free space to spare. We need to figure out * whether to merge with the forward or the backward block. * We prefer coalescing with the lower numbered sibling so as * to shrink a directory over time. */ /* start with smaller blk num */ forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back)); for (i = 0; i < 2; forward = !forward, i++) { if (forward) blkno = be32_to_cpu(info->forw); else blkno = be32_to_cpu(info->back); if (blkno == 0) continue; error = xfs_da_read_buf(state->args->trans, state->args->dp, blkno, -1, &bp, state->args->whichfork, NULL); if (error) return(error); ASSERT(bp != NULL); node = (xfs_da_intnode_t *)info; count = state->node_ents; count -= state->node_ents >> 2; count -= be16_to_cpu(node->hdr.count); node = bp->b_addr; ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); count -= be16_to_cpu(node->hdr.count); xfs_trans_brelse(state->args->trans, bp); if (count >= 0) break; /* fits with at least 25% to spare */ } if (i >= 2) { *action = 0; return(0); } /* * Make altpath point to the block we want to keep (the lower * numbered block) and path point to the block we want to drop. */ memcpy(&state->altpath, &state->path, sizeof(state->path)); if (blkno < blk->blkno) { error = xfs_da_path_shift(state, &state->altpath, forward, 0, &retval); if (error) { return(error); } if (retval) { *action = 0; return(0); } } else { error = xfs_da_path_shift(state, &state->path, forward, 0, &retval); if (error) { return(error); } if (retval) { *action = 0; return(0); } } *action = 1; return(0); } /* * Walk back up the tree adjusting hash values as necessary, * when we stop making changes, return. */ void xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path) { xfs_da_state_blk_t *blk; xfs_da_intnode_t *node; xfs_da_node_entry_t *btree; xfs_dahash_t lasthash=0; int level, count; trace_xfs_da_fixhashpath(state->args); level = path->active-1; blk = &path->blk[ level ]; switch (blk->magic) { case XFS_ATTR_LEAF_MAGIC: lasthash = xfs_attr_leaf_lasthash(blk->bp, &count); if (count == 0) return; break; case XFS_DIR2_LEAFN_MAGIC: lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count); if (count == 0) return; break; case XFS_DA_NODE_MAGIC: lasthash = xfs_da_node_lasthash(blk->bp, &count); if (count == 0) return; break; } for (blk--, level--; level >= 0; blk--, level--) { node = blk->bp->b_addr; ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); btree = &node->btree[ blk->index ]; if (be32_to_cpu(btree->hashval) == lasthash) break; blk->hashval = lasthash; btree->hashval = cpu_to_be32(lasthash); xfs_trans_log_buf(state->args->trans, blk->bp, XFS_DA_LOGRANGE(node, btree, sizeof(*btree))); lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval); } } /* * Remove an entry from an intermediate node. */ STATIC void xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk) { xfs_da_intnode_t *node; xfs_da_node_entry_t *btree; int tmp; trace_xfs_da_node_remove(state->args); node = drop_blk->bp->b_addr; ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count)); ASSERT(drop_blk->index >= 0); /* * Copy over the offending entry, or just zero it out. */ btree = &node->btree[drop_blk->index]; if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) { tmp = be16_to_cpu(node->hdr.count) - drop_blk->index - 1; tmp *= (uint)sizeof(xfs_da_node_entry_t); memmove(btree, btree + 1, tmp); xfs_trans_log_buf(state->args->trans, drop_blk->bp, XFS_DA_LOGRANGE(node, btree, tmp)); btree = &node->btree[be16_to_cpu(node->hdr.count)-1]; } memset((char *)btree, 0, sizeof(xfs_da_node_entry_t)); xfs_trans_log_buf(state->args->trans, drop_blk->bp, XFS_DA_LOGRANGE(node, btree, sizeof(*btree))); be16_add_cpu(&node->hdr.count, -1); xfs_trans_log_buf(state->args->trans, drop_blk->bp, XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr))); /* * Copy the last hash value from the block to propagate upwards. */ btree--; drop_blk->hashval = be32_to_cpu(btree->hashval); } /* * Unbalance the btree elements between two intermediate nodes, * move all Btree elements from one node into another. */ STATIC void xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk, xfs_da_state_blk_t *save_blk) { xfs_da_intnode_t *drop_node, *save_node; xfs_da_node_entry_t *btree; int tmp; xfs_trans_t *tp; trace_xfs_da_node_unbalance(state->args); drop_node = drop_blk->bp->b_addr; save_node = save_blk->bp->b_addr; ASSERT(drop_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); ASSERT(save_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); tp = state->args->trans; /* * If the dying block has lower hashvals, then move all the * elements in the remaining block up to make a hole. */ if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) || (be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) < be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval))) { btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)]; tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t); memmove(btree, &save_node->btree[0], tmp); btree = &save_node->btree[0]; xfs_trans_log_buf(tp, save_blk->bp, XFS_DA_LOGRANGE(save_node, btree, (be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) * sizeof(xfs_da_node_entry_t))); } else { btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)]; xfs_trans_log_buf(tp, save_blk->bp, XFS_DA_LOGRANGE(save_node, btree, be16_to_cpu(drop_node->hdr.count) * sizeof(xfs_da_node_entry_t))); } /* * Move all the B-tree elements from drop_blk to save_blk. */ tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t); memcpy(btree, &drop_node->btree[0], tmp); be16_add_cpu(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count)); xfs_trans_log_buf(tp, save_blk->bp, XFS_DA_LOGRANGE(save_node, &save_node->hdr, sizeof(save_node->hdr))); /* * Save the last hashval in the remaining block for upward propagation. */ save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval); } /*======================================================================== * Routines used for finding things in the Btree. *========================================================================*/ /* * Walk down the Btree looking for a particular filename, filling * in the state structure as we go. * * We will set the state structure to point to each of the elements * in each of the nodes where either the hashval is or should be. * * We support duplicate hashval's so for each entry in the current * node that could contain the desired hashval, descend. This is a * pruned depth-first tree search. */ int /* error */ xfs_da_node_lookup_int(xfs_da_state_t *state, int *result) { xfs_da_state_blk_t *blk; xfs_da_blkinfo_t *curr; xfs_da_intnode_t *node; xfs_da_node_entry_t *btree; xfs_dablk_t blkno; int probe, span, max, error, retval; xfs_dahash_t hashval, btreehashval; xfs_da_args_t *args; args = state->args; /* * Descend thru the B-tree searching each level for the right * node to use, until the right hashval is found. */ blkno = (args->whichfork == XFS_DATA_FORK)? state->mp->m_dirleafblk : 0; for (blk = &state->path.blk[0], state->path.active = 1; state->path.active <= XFS_DA_NODE_MAXDEPTH; blk++, state->path.active++) { /* * Read the next node down in the tree. */ blk->blkno = blkno; error = xfs_da_read_buf(args->trans, args->dp, blkno, -1, &blk->bp, args->whichfork, NULL); if (error) { blk->blkno = 0; state->path.active--; return(error); } curr = blk->bp->b_addr; blk->magic = be16_to_cpu(curr->magic); ASSERT(blk->magic == XFS_DA_NODE_MAGIC || blk->magic == XFS_DIR2_LEAFN_MAGIC || blk->magic == XFS_ATTR_LEAF_MAGIC); /* * Search an intermediate node for a match. */ if (blk->magic == XFS_DA_NODE_MAGIC) { node = blk->bp->b_addr; max = be16_to_cpu(node->hdr.count); blk->hashval = be32_to_cpu(node->btree[max-1].hashval); /* * Binary search. (note: small blocks will skip loop) */ probe = span = max / 2; hashval = args->hashval; for (btree = &node->btree[probe]; span > 4; btree = &node->btree[probe]) { span /= 2; btreehashval = be32_to_cpu(btree->hashval); if (btreehashval < hashval) probe += span; else if (btreehashval > hashval) probe -= span; else break; } ASSERT((probe >= 0) && (probe < max)); ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval)); /* * Since we may have duplicate hashval's, find the first * matching hashval in the node. */ while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) { btree--; probe--; } while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) { btree++; probe++; } /* * Pick the right block to descend on. */ if (probe == max) { blk->index = max-1; blkno = be32_to_cpu(node->btree[max-1].before); } else { blk->index = probe; blkno = be32_to_cpu(btree->before); } } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) { blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL); break; } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) { blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL); break; } } /* * A leaf block that ends in the hashval that we are interested in * (final hashval == search hashval) means that the next block may * contain more entries with the same hashval, shift upward to the * next leaf and keep searching. */ for (;;) { if (blk->magic == XFS_DIR2_LEAFN_MAGIC) { retval = xfs_dir2_leafn_lookup_int(blk->bp, args, &blk->index, state); } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) { retval = xfs_attr_leaf_lookup_int(blk->bp, args); blk->index = args->index; args->blkno = blk->blkno; } else { ASSERT(0); return XFS_ERROR(EFSCORRUPTED); } if (((retval == ENOENT) || (retval == ENOATTR)) && (blk->hashval == args->hashval)) { error = xfs_da_path_shift(state, &state->path, 1, 1, &retval); if (error) return(error); if (retval == 0) { continue; } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) { /* path_shift() gives ENOENT */ retval = XFS_ERROR(ENOATTR); } } break; } *result = retval; return(0); } /*======================================================================== * Utility routines. *========================================================================*/ /* * Link a new block into a doubly linked list of blocks (of whatever type). */ int /* error */ xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk, xfs_da_state_blk_t *new_blk) { xfs_da_blkinfo_t *old_info, *new_info, *tmp_info; xfs_da_args_t *args; int before=0, error; struct xfs_buf *bp; /* * Set up environment. */ args = state->args; ASSERT(args != NULL); old_info = old_blk->bp->b_addr; new_info = new_blk->bp->b_addr; ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC || old_blk->magic == XFS_DIR2_LEAFN_MAGIC || old_blk->magic == XFS_ATTR_LEAF_MAGIC); ASSERT(old_blk->magic == be16_to_cpu(old_info->magic)); ASSERT(new_blk->magic == be16_to_cpu(new_info->magic)); ASSERT(old_blk->magic == new_blk->magic); switch (old_blk->magic) { case XFS_ATTR_LEAF_MAGIC: before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp); break; case XFS_DIR2_LEAFN_MAGIC: before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp); break; case XFS_DA_NODE_MAGIC: before = xfs_da_node_order(old_blk->bp, new_blk->bp); break; } /* * Link blocks in appropriate order. */ if (before) { /* * Link new block in before existing block. */ trace_xfs_da_link_before(args); new_info->forw = cpu_to_be32(old_blk->blkno); new_info->back = old_info->back; if (old_info->back) { error = xfs_da_read_buf(args->trans, args->dp, be32_to_cpu(old_info->back), -1, &bp, args->whichfork, NULL); if (error) return(error); ASSERT(bp != NULL); tmp_info = bp->b_addr; ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic)); ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno); tmp_info->forw = cpu_to_be32(new_blk->blkno); xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1); } old_info->back = cpu_to_be32(new_blk->blkno); } else { /* * Link new block in after existing block. */ trace_xfs_da_link_after(args); new_info->forw = old_info->forw; new_info->back = cpu_to_be32(old_blk->blkno); if (old_info->forw) { error = xfs_da_read_buf(args->trans, args->dp, be32_to_cpu(old_info->forw), -1, &bp, args->whichfork, NULL); if (error) return(error); ASSERT(bp != NULL); tmp_info = bp->b_addr; ASSERT(tmp_info->magic == old_info->magic); ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno); tmp_info->back = cpu_to_be32(new_blk->blkno); xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1); } old_info->forw = cpu_to_be32(new_blk->blkno); } xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1); xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1); return(0); } /* * Compare two intermediate nodes for "order". */ STATIC int xfs_da_node_order( struct xfs_buf *node1_bp, struct xfs_buf *node2_bp) { xfs_da_intnode_t *node1, *node2; node1 = node1_bp->b_addr; node2 = node2_bp->b_addr; ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) && node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) && ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) || (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) < be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) { return(1); } return(0); } /* * Pick up the last hashvalue from an intermediate node. */ STATIC uint xfs_da_node_lasthash( struct xfs_buf *bp, int *count) { xfs_da_intnode_t *node; node = bp->b_addr; ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); if (count) *count = be16_to_cpu(node->hdr.count); if (!node->hdr.count) return(0); return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval); } /* * Unlink a block from a doubly linked list of blocks. */ STATIC int /* error */ xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk, xfs_da_state_blk_t *save_blk) { xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info; xfs_da_args_t *args; struct xfs_buf *bp; int error; /* * Set up environment. */ args = state->args; ASSERT(args != NULL); save_info = save_blk->bp->b_addr; drop_info = drop_blk->bp->b_addr; ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC || save_blk->magic == XFS_DIR2_LEAFN_MAGIC || save_blk->magic == XFS_ATTR_LEAF_MAGIC); ASSERT(save_blk->magic == be16_to_cpu(save_info->magic)); ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic)); ASSERT(save_blk->magic == drop_blk->magic); ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) || (be32_to_cpu(save_info->back) == drop_blk->blkno)); ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) || (be32_to_cpu(drop_info->back) == save_blk->blkno)); /* * Unlink the leaf block from the doubly linked chain of leaves. */ if (be32_to_cpu(save_info->back) == drop_blk->blkno) { trace_xfs_da_unlink_back(args); save_info->back = drop_info->back; if (drop_info->back) { error = xfs_da_read_buf(args->trans, args->dp, be32_to_cpu(drop_info->back), -1, &bp, args->whichfork, NULL); if (error) return(error); ASSERT(bp != NULL); tmp_info = bp->b_addr; ASSERT(tmp_info->magic == save_info->magic); ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno); tmp_info->forw = cpu_to_be32(save_blk->blkno); xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info) - 1); } } else { trace_xfs_da_unlink_forward(args); save_info->forw = drop_info->forw; if (drop_info->forw) { error = xfs_da_read_buf(args->trans, args->dp, be32_to_cpu(drop_info->forw), -1, &bp, args->whichfork, NULL); if (error) return(error); ASSERT(bp != NULL); tmp_info = bp->b_addr; ASSERT(tmp_info->magic == save_info->magic); ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno); tmp_info->back = cpu_to_be32(save_blk->blkno); xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info) - 1); } } xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1); return(0); } /* * Move a path "forward" or "!forward" one block at the current level. * * This routine will adjust a "path" to point to the next block * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the * Btree, including updating pointers to the intermediate nodes between * the new bottom and the root. */ int /* error */ xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path, int forward, int release, int *result) { xfs_da_state_blk_t *blk; xfs_da_blkinfo_t *info; xfs_da_intnode_t *node; xfs_da_args_t *args; xfs_dablk_t blkno=0; int level, error; trace_xfs_da_path_shift(state->args); /* * Roll up the Btree looking for the first block where our * current index is not at the edge of the block. Note that * we skip the bottom layer because we want the sibling block. */ args = state->args; ASSERT(args != NULL); ASSERT(path != NULL); ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH)); level = (path->active-1) - 1; /* skip bottom layer in path */ for (blk = &path->blk[level]; level >= 0; blk--, level--) { ASSERT(blk->bp != NULL); node = blk->bp->b_addr; ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) { blk->index++; blkno = be32_to_cpu(node->btree[blk->index].before); break; } else if (!forward && (blk->index > 0)) { blk->index--; blkno = be32_to_cpu(node->btree[blk->index].before); break; } } if (level < 0) { *result = XFS_ERROR(ENOENT); /* we're out of our tree */ ASSERT(args->op_flags & XFS_DA_OP_OKNOENT); return(0); } /* * Roll down the edge of the subtree until we reach the * same depth we were at originally. */ for (blk++, level++; level < path->active; blk++, level++) { /* * Release the old block. * (if it's dirty, trans won't actually let go) */ if (release) xfs_trans_brelse(args->trans, blk->bp); /* * Read the next child block. */ blk->blkno = blkno; error = xfs_da_read_buf(args->trans, args->dp, blkno, -1, &blk->bp, args->whichfork, NULL); if (error) return(error); ASSERT(blk->bp != NULL); info = blk->bp->b_addr; ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) || info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) || info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC)); blk->magic = be16_to_cpu(info->magic); if (blk->magic == XFS_DA_NODE_MAGIC) { node = (xfs_da_intnode_t *)info; blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval); if (forward) blk->index = 0; else blk->index = be16_to_cpu(node->hdr.count)-1; blkno = be32_to_cpu(node->btree[blk->index].before); } else { ASSERT(level == path->active-1); blk->index = 0; switch(blk->magic) { case XFS_ATTR_LEAF_MAGIC: blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL); break; case XFS_DIR2_LEAFN_MAGIC: blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL); break; default: ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC || blk->magic == XFS_DIR2_LEAFN_MAGIC); break; } } } *result = 0; return(0); } /*======================================================================== * Utility routines. *========================================================================*/ /* * Implement a simple hash on a character string. * Rotate the hash value by 7 bits, then XOR each character in. * This is implemented with some source-level loop unrolling. */ xfs_dahash_t xfs_da_hashname(const __uint8_t *name, int namelen) { xfs_dahash_t hash; /* * Do four characters at a time as long as we can. */ for (hash = 0; namelen >= 4; namelen -= 4, name += 4) hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^ (name[3] << 0) ^ rol32(hash, 7 * 4); /* * Now do the rest of the characters. */ switch (namelen) { case 3: return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^ rol32(hash, 7 * 3); case 2: return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2); case 1: return (name[0] << 0) ^ rol32(hash, 7 * 1); default: /* case 0: */ return hash; } } enum xfs_dacmp xfs_da_compname( struct xfs_da_args *args, const unsigned char *name, int len) { return (args->namelen == len && memcmp(args->name, name, len) == 0) ? XFS_CMP_EXACT : XFS_CMP_DIFFERENT; } static xfs_dahash_t xfs_default_hashname( struct xfs_name *name) { return xfs_da_hashname(name->name, name->len); } const struct xfs_nameops xfs_default_nameops = { .hashname = xfs_default_hashname, .compname = xfs_da_compname }; int xfs_da_grow_inode_int( struct xfs_da_args *args, xfs_fileoff_t *bno, int count) { struct xfs_trans *tp = args->trans; struct xfs_inode *dp = args->dp; int w = args->whichfork; xfs_drfsbno_t nblks = dp->i_d.di_nblocks; struct xfs_bmbt_irec map, *mapp; int nmap, error, got, i, mapi; /* * Find a spot in the file space to put the new block. */ error = xfs_bmap_first_unused(tp, dp, count, bno, w); if (error) return error; /* * Try mapping it in one filesystem block. */ nmap = 1; ASSERT(args->firstblock != NULL); error = xfs_bmapi_write(tp, dp, *bno, count, xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG, args->firstblock, args->total, &map, &nmap, args->flist); if (error) return error; ASSERT(nmap <= 1); if (nmap == 1) { mapp = ↦ mapi = 1; } else if (nmap == 0 && count > 1) { xfs_fileoff_t b; int c; /* * If we didn't get it and the block might work if fragmented, * try without the CONTIG flag. Loop until we get it all. */ mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP); for (b = *bno, mapi = 0; b < *bno + count; ) { nmap = MIN(XFS_BMAP_MAX_NMAP, count); c = (int)(*bno + count - b); error = xfs_bmapi_write(tp, dp, b, c, xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA, args->firstblock, args->total, &mapp[mapi], &nmap, args->flist); if (error) goto out_free_map; if (nmap < 1) break; mapi += nmap; b = mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount; } } else { mapi = 0; mapp = NULL; } /* * Count the blocks we got, make sure it matches the total. */ for (i = 0, got = 0; i < mapi; i++) got += mapp[i].br_blockcount; if (got != count || mapp[0].br_startoff != *bno || mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount != *bno + count) { error = XFS_ERROR(ENOSPC); goto out_free_map; } /* account for newly allocated blocks in reserved blocks total */ args->total -= dp->i_d.di_nblocks - nblks; out_free_map: if (mapp != &map) kmem_free(mapp); return error; } /* * Add a block to the btree ahead of the file. * Return the new block number to the caller. */ int xfs_da_grow_inode( struct xfs_da_args *args, xfs_dablk_t *new_blkno) { xfs_fileoff_t bno; int count; int error; trace_xfs_da_grow_inode(args); if (args->whichfork == XFS_DATA_FORK) { bno = args->dp->i_mount->m_dirleafblk; count = args->dp->i_mount->m_dirblkfsbs; } else { bno = 0; count = 1; } error = xfs_da_grow_inode_int(args, &bno, count); if (!error) *new_blkno = (xfs_dablk_t)bno; return error; } /* * Ick. We need to always be able to remove a btree block, even * if there's no space reservation because the filesystem is full. * This is called if xfs_bunmapi on a btree block fails due to ENOSPC. * It swaps the target block with the last block in the file. The * last block in the file can always be removed since it can't cause * a bmap btree split to do that. */ STATIC int xfs_da_swap_lastblock( xfs_da_args_t *args, xfs_dablk_t *dead_blknop, struct xfs_buf **dead_bufp) { xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno; struct xfs_buf *dead_buf, *last_buf, *sib_buf, *par_buf; xfs_fileoff_t lastoff; xfs_inode_t *ip; xfs_trans_t *tp; xfs_mount_t *mp; int error, w, entno, level, dead_level; xfs_da_blkinfo_t *dead_info, *sib_info; xfs_da_intnode_t *par_node, *dead_node; xfs_dir2_leaf_t *dead_leaf2; xfs_dahash_t dead_hash; trace_xfs_da_swap_lastblock(args); dead_buf = *dead_bufp; dead_blkno = *dead_blknop; tp = args->trans; ip = args->dp; w = args->whichfork; ASSERT(w == XFS_DATA_FORK); mp = ip->i_mount; lastoff = mp->m_dirfreeblk; error = xfs_bmap_last_before(tp, ip, &lastoff, w); if (error) return error; if (unlikely(lastoff == 0)) { XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW, mp); return XFS_ERROR(EFSCORRUPTED); } /* * Read the last block in the btree space. */ last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs; error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w, NULL); if (error) return error; /* * Copy the last block into the dead buffer and log it. */ memcpy(dead_buf->b_addr, last_buf->b_addr, mp->m_dirblksize); xfs_trans_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1); dead_info = dead_buf->b_addr; /* * Get values from the moved block. */ if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) { dead_leaf2 = (xfs_dir2_leaf_t *)dead_info; dead_level = 0; dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval); } else { ASSERT(dead_info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC)); dead_node = (xfs_da_intnode_t *)dead_info; dead_level = be16_to_cpu(dead_node->hdr.level); dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval); } sib_buf = par_buf = NULL; /* * If the moved block has a left sibling, fix up the pointers. */ if ((sib_blkno = be32_to_cpu(dead_info->back))) { error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w, NULL); if (error) goto done; sib_info = sib_buf->b_addr; if (unlikely( be32_to_cpu(sib_info->forw) != last_blkno || sib_info->magic != dead_info->magic)) { XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto done; } sib_info->forw = cpu_to_be32(dead_blkno); xfs_trans_log_buf(tp, sib_buf, XFS_DA_LOGRANGE(sib_info, &sib_info->forw, sizeof(sib_info->forw))); sib_buf = NULL; } /* * If the moved block has a right sibling, fix up the pointers. */ if ((sib_blkno = be32_to_cpu(dead_info->forw))) { error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w, NULL); if (error) goto done; sib_info = sib_buf->b_addr; if (unlikely( be32_to_cpu(sib_info->back) != last_blkno || sib_info->magic != dead_info->magic)) { XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto done; } sib_info->back = cpu_to_be32(dead_blkno); xfs_trans_log_buf(tp, sib_buf, XFS_DA_LOGRANGE(sib_info, &sib_info->back, sizeof(sib_info->back))); sib_buf = NULL; } par_blkno = mp->m_dirleafblk; level = -1; /* * Walk down the tree looking for the parent of the moved block. */ for (;;) { error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w, NULL); if (error) goto done; par_node = par_buf->b_addr; if (unlikely(par_node->hdr.info.magic != cpu_to_be16(XFS_DA_NODE_MAGIC) || (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) { XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto done; } level = be16_to_cpu(par_node->hdr.level); for (entno = 0; entno < be16_to_cpu(par_node->hdr.count) && be32_to_cpu(par_node->btree[entno].hashval) < dead_hash; entno++) continue; if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) { XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto done; } par_blkno = be32_to_cpu(par_node->btree[entno].before); if (level == dead_level + 1) break; xfs_trans_brelse(tp, par_buf); par_buf = NULL; } /* * We're in the right parent block. * Look for the right entry. */ for (;;) { for (; entno < be16_to_cpu(par_node->hdr.count) && be32_to_cpu(par_node->btree[entno].before) != last_blkno; entno++) continue; if (entno < be16_to_cpu(par_node->hdr.count)) break; par_blkno = be32_to_cpu(par_node->hdr.info.forw); xfs_trans_brelse(tp, par_buf); par_buf = NULL; if (unlikely(par_blkno == 0)) { XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto done; } error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w, NULL); if (error) goto done; par_node = par_buf->b_addr; if (unlikely( be16_to_cpu(par_node->hdr.level) != level || par_node->hdr.info.magic != cpu_to_be16(XFS_DA_NODE_MAGIC))) { XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto done; } entno = 0; } /* * Update the parent entry pointing to the moved block. */ par_node->btree[entno].before = cpu_to_be32(dead_blkno); xfs_trans_log_buf(tp, par_buf, XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before, sizeof(par_node->btree[entno].before))); *dead_blknop = last_blkno; *dead_bufp = last_buf; return 0; done: if (par_buf) xfs_trans_brelse(tp, par_buf); if (sib_buf) xfs_trans_brelse(tp, sib_buf); xfs_trans_brelse(tp, last_buf); return error; } /* * Remove a btree block from a directory or attribute. */ int xfs_da_shrink_inode( xfs_da_args_t *args, xfs_dablk_t dead_blkno, struct xfs_buf *dead_buf) { xfs_inode_t *dp; int done, error, w, count; xfs_trans_t *tp; xfs_mount_t *mp; trace_xfs_da_shrink_inode(args); dp = args->dp; w = args->whichfork; tp = args->trans; mp = dp->i_mount; if (w == XFS_DATA_FORK) count = mp->m_dirblkfsbs; else count = 1; for (;;) { /* * Remove extents. If we get ENOSPC for a dir we have to move * the last block to the place we want to kill. */ if ((error = xfs_bunmapi(tp, dp, dead_blkno, count, xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA, 0, args->firstblock, args->flist, &done)) == ENOSPC) { if (w != XFS_DATA_FORK) break; if ((error = xfs_da_swap_lastblock(args, &dead_blkno, &dead_buf))) break; } else { break; } } xfs_trans_binval(tp, dead_buf); return error; } /* * See if the mapping(s) for this btree block are valid, i.e. * don't contain holes, are logically contiguous, and cover the whole range. */ STATIC int xfs_da_map_covers_blocks( int nmap, xfs_bmbt_irec_t *mapp, xfs_dablk_t bno, int count) { int i; xfs_fileoff_t off; for (i = 0, off = bno; i < nmap; i++) { if (mapp[i].br_startblock == HOLESTARTBLOCK || mapp[i].br_startblock == DELAYSTARTBLOCK) { return 0; } if (off != mapp[i].br_startoff) { return 0; } off += mapp[i].br_blockcount; } return off == bno + count; } /* * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map. * * For the single map case, it is assumed that the caller has provided a pointer * to a valid xfs_buf_map. For the multiple map case, this function will * allocate the xfs_buf_map to hold all the maps and replace the caller's single * map pointer with the allocated map. */ static int xfs_buf_map_from_irec( struct xfs_mount *mp, struct xfs_buf_map **mapp, unsigned int *nmaps, struct xfs_bmbt_irec *irecs, unsigned int nirecs) { struct xfs_buf_map *map; int i; ASSERT(*nmaps == 1); ASSERT(nirecs >= 1); if (nirecs > 1) { map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_SLEEP); if (!map) return ENOMEM; *mapp = map; } *nmaps = nirecs; map = *mapp; for (i = 0; i < *nmaps; i++) { ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK && irecs[i].br_startblock != HOLESTARTBLOCK); map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock); map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount); } return 0; } /* * Map the block we are given ready for reading. There are three possible return * values: * -1 - will be returned if we land in a hole and mappedbno == -2 so the * caller knows not to execute a subsequent read. * 0 - if we mapped the block successfully * >0 - positive error number if there was an error. */ static int xfs_dabuf_map( struct xfs_trans *trans, struct xfs_inode *dp, xfs_dablk_t bno, xfs_daddr_t mappedbno, int whichfork, struct xfs_buf_map **map, int *nmaps) { struct xfs_mount *mp = dp->i_mount; int nfsb; int error = 0; struct xfs_bmbt_irec irec; struct xfs_bmbt_irec *irecs = &irec; int nirecs; ASSERT(map && *map); ASSERT(*nmaps == 1); nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1; /* * Caller doesn't have a mapping. -2 means don't complain * if we land in a hole. */ if (mappedbno == -1 || mappedbno == -2) { /* * Optimize the one-block case. */ if (nfsb != 1) irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_SLEEP); nirecs = nfsb; error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs, &nirecs, xfs_bmapi_aflag(whichfork)); if (error) goto out; } else { irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno); irecs->br_startoff = (xfs_fileoff_t)bno; irecs->br_blockcount = nfsb; irecs->br_state = 0; nirecs = 1; } if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) { error = mappedbno == -2 ? -1 : XFS_ERROR(EFSCORRUPTED); if (unlikely(error == EFSCORRUPTED)) { if (xfs_error_level >= XFS_ERRLEVEL_LOW) { int i; xfs_alert(mp, "%s: bno %lld dir: inode %lld", __func__, (long long)bno, (long long)dp->i_ino); for (i = 0; i < *nmaps; i++) { xfs_alert(mp, "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d", i, (long long)irecs[i].br_startoff, (long long)irecs[i].br_startblock, (long long)irecs[i].br_blockcount, irecs[i].br_state); } } XFS_ERROR_REPORT("xfs_da_do_buf(1)", XFS_ERRLEVEL_LOW, mp); } goto out; } error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs); out: if (irecs != &irec) kmem_free(irecs); return error; } /* * Get a buffer for the dir/attr block. */ int xfs_da_get_buf( struct xfs_trans *trans, struct xfs_inode *dp, xfs_dablk_t bno, xfs_daddr_t mappedbno, struct xfs_buf **bpp, int whichfork) { struct xfs_buf *bp; struct xfs_buf_map map; struct xfs_buf_map *mapp; int nmap; int error; *bpp = NULL; mapp = ↦ nmap = 1; error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork, &mapp, &nmap); if (error) { /* mapping a hole is not an error, but we don't continue */ if (error == -1) error = 0; goto out_free; } bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp, mapp, nmap, 0); error = bp ? bp->b_error : XFS_ERROR(EIO); if (error) { xfs_trans_brelse(trans, bp); goto out_free; } *bpp = bp; out_free: if (mapp != &map) kmem_free(mapp); return error; } /* * Get a buffer for the dir/attr block, fill in the contents. */ int xfs_da_read_buf( struct xfs_trans *trans, struct xfs_inode *dp, xfs_dablk_t bno, xfs_daddr_t mappedbno, struct xfs_buf **bpp, int whichfork, xfs_buf_iodone_t verifier) { struct xfs_buf *bp; struct xfs_buf_map map; struct xfs_buf_map *mapp; int nmap; int error; *bpp = NULL; mapp = ↦ nmap = 1; error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork, &mapp, &nmap); if (error) { /* mapping a hole is not an error, but we don't continue */ if (error == -1) error = 0; goto out_free; } error = xfs_trans_read_buf_map(dp->i_mount, trans, dp->i_mount->m_ddev_targp, mapp, nmap, 0, &bp, verifier); if (error) goto out_free; if (whichfork == XFS_ATTR_FORK) xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF); else xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF); /* * This verification code will be moved to a CRC verification callback * function so just leave it here unchanged until then. */ { xfs_dir2_data_hdr_t *hdr = bp->b_addr; xfs_dir2_free_t *free = bp->b_addr; xfs_da_blkinfo_t *info = bp->b_addr; uint magic, magic1; struct xfs_mount *mp = dp->i_mount; magic = be16_to_cpu(info->magic); magic1 = be32_to_cpu(hdr->magic); if (unlikely( XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) && (magic != XFS_ATTR_LEAF_MAGIC) && (magic != XFS_DIR2_LEAF1_MAGIC) && (magic != XFS_DIR2_LEAFN_MAGIC) && (magic1 != XFS_DIR2_BLOCK_MAGIC) && (magic1 != XFS_DIR2_DATA_MAGIC) && (free->hdr.magic != cpu_to_be32(XFS_DIR2_FREE_MAGIC)), mp, XFS_ERRTAG_DA_READ_BUF, XFS_RANDOM_DA_READ_BUF))) { trace_xfs_da_btree_corrupt(bp, _RET_IP_); XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)", XFS_ERRLEVEL_LOW, mp, info); error = XFS_ERROR(EFSCORRUPTED); xfs_trans_brelse(trans, bp); goto out_free; } } *bpp = bp; out_free: if (mapp != &map) kmem_free(mapp); return error; } /* * Readahead the dir/attr block. */ xfs_daddr_t xfs_da_reada_buf( struct xfs_trans *trans, struct xfs_inode *dp, xfs_dablk_t bno, int whichfork, xfs_buf_iodone_t verifier) { xfs_daddr_t mappedbno = -1; struct xfs_buf_map map; struct xfs_buf_map *mapp; int nmap; int error; mapp = ↦ nmap = 1; error = xfs_dabuf_map(trans, dp, bno, -1, whichfork, &mapp, &nmap); if (error) { /* mapping a hole is not an error, but we don't continue */ if (error == -1) error = 0; goto out_free; } mappedbno = mapp[0].bm_bn; xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, NULL); out_free: if (mapp != &map) kmem_free(mapp); if (error) return -1; return mappedbno; } kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */ /* * Allocate a dir-state structure. * We don't put them on the stack since they're large. */ xfs_da_state_t * xfs_da_state_alloc(void) { return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS); } /* * Kill the altpath contents of a da-state structure. */ STATIC void xfs_da_state_kill_altpath(xfs_da_state_t *state) { int i; for (i = 0; i < state->altpath.active; i++) state->altpath.blk[i].bp = NULL; state->altpath.active = 0; } /* * Free a da-state structure. */ void xfs_da_state_free(xfs_da_state_t *state) { xfs_da_state_kill_altpath(state); #ifdef DEBUG memset((char *)state, 0, sizeof(*state)); #endif /* DEBUG */ kmem_zone_free(xfs_da_state_zone, state); }