new file mode 100644
@@ -0,0 +1,1474 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/indirect.c
+ *
+ * from
+ *
+ * linux/fs/ext4/inode.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/inode.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Goal-directed block allocation by Stephen Tweedie
+ * (sct@redhat.com), 1993, 1998
+ */
+
+#include "ext4_jbd2.h"
+#include "truncate.h"
+#include <linux/dax.h>
+#include <linux/uio.h>
+
+#include <trace/events/ext4.h>
+
+typedef struct {
+ __le32 *p;
+ __le32 key;
+ struct buffer_head *bh;
+} Indirect;
+
+static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
+{
+ p->key = *(p->p = v);
+ p->bh = bh;
+}
+
+/**
+ * ext4_block_to_path - parse the block number into array of offsets
+ * @inode: inode in question (we are only interested in its superblock)
+ * @i_block: block number to be parsed
+ * @offsets: array to store the offsets in
+ * @boundary: set this non-zero if the referred-to block is likely to be
+ * followed (on disk) by an indirect block.
+ *
+ * To store the locations of file's data ext4 uses a data structure common
+ * for UNIX filesystems - tree of pointers anchored in the inode, with
+ * data blocks at leaves and indirect blocks in intermediate nodes.
+ * This function translates the block number into path in that tree -
+ * return value is the path length and @offsets[n] is the offset of
+ * pointer to (n+1)th node in the nth one. If @block is out of range
+ * (negative or too large) warning is printed and zero returned.
+ *
+ * Note: function doesn't find node addresses, so no IO is needed. All
+ * we need to know is the capacity of indirect blocks (taken from the
+ * inode->i_sb).
+ */
+
+/*
+ * Portability note: the last comparison (check that we fit into triple
+ * indirect block) is spelled differently, because otherwise on an
+ * architecture with 32-bit longs and 8Kb pages we might get into trouble
+ * if our filesystem had 8Kb blocks. We might use long long, but that would
+ * kill us on x86. Oh, well, at least the sign propagation does not matter -
+ * i_block would have to be negative in the very beginning, so we would not
+ * get there at all.
+ */
+
+static int ext4_block_to_path(struct inode *inode,
+ ext4_lblk_t i_block,
+ ext4_lblk_t offsets[4], int *boundary)
+{
+ int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+ int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
+ const long direct_blocks = EXT4_NDIR_BLOCKS,
+ indirect_blocks = ptrs,
+ double_blocks = (1 << (ptrs_bits * 2));
+ int n = 0;
+ int final = 0;
+
+ if (i_block < direct_blocks) {
+ offsets[n++] = i_block;
+ final = direct_blocks;
+ } else if ((i_block -= direct_blocks) < indirect_blocks) {
+ offsets[n++] = EXT4_IND_BLOCK;
+ offsets[n++] = i_block;
+ final = ptrs;
+ } else if ((i_block -= indirect_blocks) < double_blocks) {
+ offsets[n++] = EXT4_DIND_BLOCK;
+ offsets[n++] = i_block >> ptrs_bits;
+ offsets[n++] = i_block & (ptrs - 1);
+ final = ptrs;
+ } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
+ offsets[n++] = EXT4_TIND_BLOCK;
+ offsets[n++] = i_block >> (ptrs_bits * 2);
+ offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
+ offsets[n++] = i_block & (ptrs - 1);
+ final = ptrs;
+ } else {
+ ext4_warning(inode->i_sb, "block %lu > max in inode %lu",
+ i_block + direct_blocks +
+ indirect_blocks + double_blocks, inode->i_ino);
+ }
+ if (boundary)
+ *boundary = final - 1 - (i_block & (ptrs - 1));
+ return n;
+}
+
+/**
+ * ext4_get_branch - read the chain of indirect blocks leading to data
+ * @inode: inode in question
+ * @depth: depth of the chain (1 - direct pointer, etc.)
+ * @offsets: offsets of pointers in inode/indirect blocks
+ * @chain: place to store the result
+ * @err: here we store the error value
+ *
+ * Function fills the array of triples <key, p, bh> and returns %NULL
+ * if everything went OK or the pointer to the last filled triple
+ * (incomplete one) otherwise. Upon the return chain[i].key contains
+ * the number of (i+1)-th block in the chain (as it is stored in memory,
+ * i.e. little-endian 32-bit), chain[i].p contains the address of that
+ * number (it points into struct inode for i==0 and into the bh->b_data
+ * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
+ * block for i>0 and NULL for i==0. In other words, it holds the block
+ * numbers of the chain, addresses they were taken from (and where we can
+ * verify that chain did not change) and buffer_heads hosting these
+ * numbers.
+ *
+ * Function stops when it stumbles upon zero pointer (absent block)
+ * (pointer to last triple returned, *@err == 0)
+ * or when it gets an IO error reading an indirect block
+ * (ditto, *@err == -EIO)
+ * or when it reads all @depth-1 indirect blocks successfully and finds
+ * the whole chain, all way to the data (returns %NULL, *err == 0).
+ *
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem)
+ */
+static Indirect *ext4_get_branch(struct inode *inode, int depth,
+ ext4_lblk_t *offsets,
+ Indirect chain[4], int *err)
+{
+ struct super_block *sb = inode->i_sb;
+ Indirect *p = chain;
+ struct buffer_head *bh;
+ unsigned int key;
+ int ret = -EIO;
+
+ *err = 0;
+ /* i_data is not going away, no lock needed */
+ add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
+ if (!p->key)
+ goto no_block;
+ while (--depth) {
+ key = le32_to_cpu(p->key);
+ if (key > ext4_blocks_count(EXT4_SB(sb)->s_es)) {
+ /* the block was out of range */
+ ret = -EFSCORRUPTED;
+ goto failure;
+ }
+ bh = sb_getblk(sb, key);
+ if (unlikely(!bh)) {
+ ret = -ENOMEM;
+ goto failure;
+ }
+
+ if (!bh_uptodate_or_lock(bh)) {
+ if (ext4_read_bh(bh, 0, NULL, false) < 0) {
+ put_bh(bh);
+ goto failure;
+ }
+ /* validate block references */
+ if (ext4_check_indirect_blockref(inode, bh)) {
+ put_bh(bh);
+ goto failure;
+ }
+ }
+
+ add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
+ /* Reader: end */
+ if (!p->key)
+ goto no_block;
+ }
+ return NULL;
+
+failure:
+ *err = ret;
+no_block:
+ return p;
+}
+
+/**
+ * ext4_find_near - find a place for allocation with sufficient locality
+ * @inode: owner
+ * @ind: descriptor of indirect block.
+ *
+ * This function returns the preferred place for block allocation.
+ * It is used when heuristic for sequential allocation fails.
+ * Rules are:
+ * + if there is a block to the left of our position - allocate near it.
+ * + if pointer will live in indirect block - allocate near that block.
+ * + if pointer will live in inode - allocate in the same
+ * cylinder group.
+ *
+ * In the latter case we colour the starting block by the callers PID to
+ * prevent it from clashing with concurrent allocations for a different inode
+ * in the same block group. The PID is used here so that functionally related
+ * files will be close-by on-disk.
+ *
+ * Caller must make sure that @ind is valid and will stay that way.
+ */
+static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
+ __le32 *p;
+
+ /* Try to find previous block */
+ for (p = ind->p - 1; p >= start; p--) {
+ if (*p)
+ return le32_to_cpu(*p);
+ }
+
+ /* No such thing, so let's try location of indirect block */
+ if (ind->bh)
+ return ind->bh->b_blocknr;
+
+ /*
+ * It is going to be referred to from the inode itself? OK, just put it
+ * into the same cylinder group then.
+ */
+ return ext4_inode_to_goal_block(inode);
+}
+
+/**
+ * ext4_find_goal - find a preferred place for allocation.
+ * @inode: owner
+ * @block: block we want
+ * @partial: pointer to the last triple within a chain
+ *
+ * Normally this function find the preferred place for block allocation,
+ * returns it.
+ * Because this is only used for non-extent files, we limit the block nr
+ * to 32 bits.
+ */
+static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
+ Indirect *partial)
+{
+ ext4_fsblk_t goal;
+
+ /*
+ * XXX need to get goal block from mballoc's data structures
+ */
+
+ goal = ext4_find_near(inode, partial);
+ goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
+ return goal;
+}
+
+/**
+ * ext4_blks_to_allocate - Look up the block map and count the number
+ * of direct blocks need to be allocated for the given branch.
+ *
+ * @branch: chain of indirect blocks
+ * @k: number of blocks need for indirect blocks
+ * @blks: number of data blocks to be mapped.
+ * @blocks_to_boundary: the offset in the indirect block
+ *
+ * return the total number of blocks to be allocate, including the
+ * direct and indirect blocks.
+ */
+static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
+ int blocks_to_boundary)
+{
+ unsigned int count = 0;
+
+ /*
+ * Simple case, [t,d]Indirect block(s) has not allocated yet
+ * then it's clear blocks on that path have not allocated
+ */
+ if (k > 0) {
+ /* right now we don't handle cross boundary allocation */
+ if (blks < blocks_to_boundary + 1)
+ count += blks;
+ else
+ count += blocks_to_boundary + 1;
+ return count;
+ }
+
+ count++;
+ while (count < blks && count <= blocks_to_boundary &&
+ le32_to_cpu(*(branch[0].p + count)) == 0) {
+ count++;
+ }
+ return count;
+}
+
+/**
+ * ext4_alloc_branch() - allocate and set up a chain of blocks
+ * @handle: handle for this transaction
+ * @ar: structure describing the allocation request
+ * @indirect_blks: number of allocated indirect blocks
+ * @offsets: offsets (in the blocks) to store the pointers to next.
+ * @branch: place to store the chain in.
+ *
+ * This function allocates blocks, zeroes out all but the last one,
+ * links them into chain and (if we are synchronous) writes them to disk.
+ * In other words, it prepares a branch that can be spliced onto the
+ * inode. It stores the information about that chain in the branch[], in
+ * the same format as ext4_get_branch() would do. We are calling it after
+ * we had read the existing part of chain and partial points to the last
+ * triple of that (one with zero ->key). Upon the exit we have the same
+ * picture as after the successful ext4_get_block(), except that in one
+ * place chain is disconnected - *branch->p is still zero (we did not
+ * set the last link), but branch->key contains the number that should
+ * be placed into *branch->p to fill that gap.
+ *
+ * If allocation fails we free all blocks we've allocated (and forget
+ * their buffer_heads) and return the error value the from failed
+ * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
+ * as described above and return 0.
+ */
+static int ext4_alloc_branch(handle_t *handle,
+ struct ext4_allocation_request *ar,
+ int indirect_blks, ext4_lblk_t *offsets,
+ Indirect *branch)
+{
+ struct buffer_head * bh;
+ ext4_fsblk_t b, new_blocks[4];
+ __le32 *p;
+ int i, j, err, len = 1;
+
+ for (i = 0; i <= indirect_blks; i++) {
+ if (i == indirect_blks) {
+ new_blocks[i] = ext4_mb_new_blocks(handle, ar, &err);
+ } else {
+ ar->goal = new_blocks[i] = ext4_new_meta_blocks(handle,
+ ar->inode, ar->goal,
+ ar->flags & EXT4_MB_DELALLOC_RESERVED,
+ NULL, &err);
+ /* Simplify error cleanup... */
+ branch[i+1].bh = NULL;
+ }
+ if (err) {
+ i--;
+ goto failed;
+ }
+ branch[i].key = cpu_to_le32(new_blocks[i]);
+ if (i == 0)
+ continue;
+
+ bh = branch[i].bh = sb_getblk(ar->inode->i_sb, new_blocks[i-1]);
+ if (unlikely(!bh)) {
+ err = -ENOMEM;
+ goto failed;
+ }
+ lock_buffer(bh);
+ BUFFER_TRACE(bh, "call get_create_access");
+ err = ext4_journal_get_create_access(handle, ar->inode->i_sb,
+ bh, EXT4_JTR_NONE);
+ if (err) {
+ unlock_buffer(bh);
+ goto failed;
+ }
+
+ memset(bh->b_data, 0, bh->b_size);
+ p = branch[i].p = (__le32 *) bh->b_data + offsets[i];
+ b = new_blocks[i];
+
+ if (i == indirect_blks)
+ len = ar->len;
+ for (j = 0; j < len; j++)
+ *p++ = cpu_to_le32(b++);
+
+ BUFFER_TRACE(bh, "marking uptodate");
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+
+ BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+ err = ext4_handle_dirty_metadata(handle, ar->inode, bh);
+ if (err)
+ goto failed;
+ }
+ return 0;
+failed:
+ if (i == indirect_blks) {
+ /* Free data blocks */
+ ext4_free_blocks(handle, ar->inode, NULL, new_blocks[i],
+ ar->len, 0);
+ i--;
+ }
+ for (; i >= 0; i--) {
+ /*
+ * We want to ext4_forget() only freshly allocated indirect
+ * blocks. Buffer for new_blocks[i] is at branch[i+1].bh
+ * (buffer at branch[0].bh is indirect block / inode already
+ * existing before ext4_alloc_branch() was called). Also
+ * because blocks are freshly allocated, we don't need to
+ * revoke them which is why we don't set
+ * EXT4_FREE_BLOCKS_METADATA.
+ */
+ ext4_free_blocks(handle, ar->inode, branch[i+1].bh,
+ new_blocks[i], 1,
+ branch[i+1].bh ? EXT4_FREE_BLOCKS_FORGET : 0);
+ }
+ return err;
+}
+
+/**
+ * ext4_splice_branch() - splice the allocated branch onto inode.
+ * @handle: handle for this transaction
+ * @ar: structure describing the allocation request
+ * @where: location of missing link
+ * @num: number of indirect blocks we are adding
+ *
+ * This function fills the missing link and does all housekeeping needed in
+ * inode (->i_blocks, etc.). In case of success we end up with the full
+ * chain to new block and return 0.
+ */
+static int ext4_splice_branch(handle_t *handle,
+ struct ext4_allocation_request *ar,
+ Indirect *where, int num)
+{
+ int i;
+ int err = 0;
+ ext4_fsblk_t current_block;
+
+ /*
+ * If we're splicing into a [td]indirect block (as opposed to the
+ * inode) then we need to get write access to the [td]indirect block
+ * before the splice.
+ */
+ if (where->bh) {
+ BUFFER_TRACE(where->bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, ar->inode->i_sb,
+ where->bh, EXT4_JTR_NONE);
+ if (err)
+ goto err_out;
+ }
+ /* That's it */
+
+ *where->p = where->key;
+
+ /*
+ * Update the host buffer_head or inode to point to more just allocated
+ * direct blocks blocks
+ */
+ if (num == 0 && ar->len > 1) {
+ current_block = le32_to_cpu(where->key) + 1;
+ for (i = 1; i < ar->len; i++)
+ *(where->p + i) = cpu_to_le32(current_block++);
+ }
+
+ /* We are done with atomic stuff, now do the rest of housekeeping */
+ /* had we spliced it onto indirect block? */
+ if (where->bh) {
+ /*
+ * If we spliced it onto an indirect block, we haven't
+ * altered the inode. Note however that if it is being spliced
+ * onto an indirect block at the very end of the file (the
+ * file is growing) then we *will* alter the inode to reflect
+ * the new i_size. But that is not done here - it is done in
+ * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
+ */
+ ext4_debug("splicing indirect only\n");
+ BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
+ err = ext4_handle_dirty_metadata(handle, ar->inode, where->bh);
+ if (err)
+ goto err_out;
+ } else {
+ /*
+ * OK, we spliced it into the inode itself on a direct block.
+ */
+ err = ext4_mark_inode_dirty(handle, ar->inode);
+ if (unlikely(err))
+ goto err_out;
+ ext4_debug("splicing direct\n");
+ }
+ return err;
+
+err_out:
+ for (i = 1; i <= num; i++) {
+ /*
+ * branch[i].bh is newly allocated, so there is no
+ * need to revoke the block, which is why we don't
+ * need to set EXT4_FREE_BLOCKS_METADATA.
+ */
+ ext4_free_blocks(handle, ar->inode, where[i].bh, 0, 1,
+ EXT4_FREE_BLOCKS_FORGET);
+ }
+ ext4_free_blocks(handle, ar->inode, NULL, le32_to_cpu(where[num].key),
+ ar->len, 0);
+
+ return err;
+}
+
+/*
+ * The ext4_ind_map_blocks() function handles non-extents inodes
+ * (i.e., using the traditional indirect/double-indirect i_blocks
+ * scheme) for ext4_map_blocks().
+ *
+ * Allocation strategy is simple: if we have to allocate something, we will
+ * have to go the whole way to leaf. So let's do it before attaching anything
+ * to tree, set linkage between the newborn blocks, write them if sync is
+ * required, recheck the path, free and repeat if check fails, otherwise
+ * set the last missing link (that will protect us from any truncate-generated
+ * removals - all blocks on the path are immune now) and possibly force the
+ * write on the parent block.
+ * That has a nice additional property: no special recovery from the failed
+ * allocations is needed - we simply release blocks and do not touch anything
+ * reachable from inode.
+ *
+ * `handle' can be NULL if create == 0.
+ *
+ * return > 0, # of blocks mapped or allocated.
+ * return = 0, if plain lookup failed.
+ * return < 0, error case.
+ *
+ * The ext4_ind_get_blocks() function should be called with
+ * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
+ * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
+ * blocks.
+ */
+int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map,
+ int flags)
+{
+ struct ext4_allocation_request ar;
+ int err = -EIO;
+ ext4_lblk_t offsets[4];
+ Indirect chain[4];
+ Indirect *partial;
+ int indirect_blks;
+ int blocks_to_boundary = 0;
+ int depth;
+ u64 count = 0;
+ ext4_fsblk_t first_block = 0;
+
+ trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
+ ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
+ ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
+ depth = ext4_block_to_path(inode, map->m_lblk, offsets,
+ &blocks_to_boundary);
+
+ if (depth == 0)
+ goto out;
+
+ partial = ext4_get_branch(inode, depth, offsets, chain, &err);
+
+ /* Simplest case - block found, no allocation needed */
+ if (!partial) {
+ first_block = le32_to_cpu(chain[depth - 1].key);
+ count++;
+ /*map more blocks*/
+ while (count < map->m_len && count <= blocks_to_boundary) {
+ ext4_fsblk_t blk;
+
+ blk = le32_to_cpu(*(chain[depth-1].p + count));
+
+ if (blk == first_block + count)
+ count++;
+ else
+ break;
+ }
+ goto got_it;
+ }
+
+ /* Next simple case - plain lookup failed */
+ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
+ unsigned epb = inode->i_sb->s_blocksize / sizeof(u32);
+ int i;
+
+ /*
+ * Count number blocks in a subtree under 'partial'. At each
+ * level we count number of complete empty subtrees beyond
+ * current offset and then descend into the subtree only
+ * partially beyond current offset.
+ */
+ count = 0;
+ for (i = partial - chain + 1; i < depth; i++)
+ count = count * epb + (epb - offsets[i] - 1);
+ count++;
+ /* Fill in size of a hole we found */
+ map->m_pblk = 0;
+ map->m_len = umin(map->m_len, count);
+ goto cleanup;
+ }
+
+ /* Failed read of indirect block */
+ if (err == -EIO)
+ goto cleanup;
+
+ /*
+ * Okay, we need to do block allocation.
+ */
+ if (ext4_has_feature_bigalloc(inode->i_sb)) {
+ EXT4_ERROR_INODE(inode, "Can't allocate blocks for "
+ "non-extent mapped inodes with bigalloc");
+ err = -EFSCORRUPTED;
+ goto out;
+ }
+
+ /* Set up for the direct block allocation */
+ memset(&ar, 0, sizeof(ar));
+ ar.inode = inode;
+ ar.logical = map->m_lblk;
+ if (S_ISREG(inode->i_mode))
+ ar.flags = EXT4_MB_HINT_DATA;
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
+ ar.flags |= EXT4_MB_DELALLOC_RESERVED;
+ if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+ ar.flags |= EXT4_MB_USE_RESERVED;
+
+ ar.goal = ext4_find_goal(inode, map->m_lblk, partial);
+
+ /* the number of blocks need to allocate for [d,t]indirect blocks */
+ indirect_blks = (chain + depth) - partial - 1;
+
+ /*
+ * Next look up the indirect map to count the totoal number of
+ * direct blocks to allocate for this branch.
+ */
+ ar.len = ext4_blks_to_allocate(partial, indirect_blks,
+ map->m_len, blocks_to_boundary);
+
+ /*
+ * Block out ext4_truncate while we alter the tree
+ */
+ err = ext4_alloc_branch(handle, &ar, indirect_blks,
+ offsets + (partial - chain), partial);
+
+ /*
+ * The ext4_splice_branch call will free and forget any buffers
+ * on the new chain if there is a failure, but that risks using
+ * up transaction credits, especially for bitmaps where the
+ * credits cannot be returned. Can we handle this somehow? We
+ * may need to return -EAGAIN upwards in the worst case. --sct
+ */
+ if (!err)
+ err = ext4_splice_branch(handle, &ar, partial, indirect_blks);
+ if (err)
+ goto cleanup;
+
+ map->m_flags |= EXT4_MAP_NEW;
+
+ ext4_update_inode_fsync_trans(handle, inode, 1);
+ count = ar.len;
+
+got_it:
+ map->m_flags |= EXT4_MAP_MAPPED;
+ map->m_pblk = le32_to_cpu(chain[depth-1].key);
+ map->m_len = count;
+ if (count > blocks_to_boundary)
+ map->m_flags |= EXT4_MAP_BOUNDARY;
+ err = count;
+ /* Clean up and exit */
+ partial = chain + depth - 1; /* the whole chain */
+cleanup:
+ while (partial > chain) {
+ BUFFER_TRACE(partial->bh, "call brelse");
+ brelse(partial->bh);
+ partial--;
+ }
+out:
+ trace_ext4_ind_map_blocks_exit(inode, flags, map, err);
+ return err;
+}
+
+/*
+ * Calculate number of indirect blocks touched by mapping @nrblocks logically
+ * contiguous blocks
+ */
+int ext4_ind_trans_blocks(struct inode *inode, int nrblocks)
+{
+ /*
+ * With N contiguous data blocks, we need at most
+ * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+ * 2 dindirect blocks, and 1 tindirect block
+ */
+ return DIV_ROUND_UP(nrblocks, EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
+}
+
+static int ext4_ind_trunc_restart_fn(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh, int *dropped)
+{
+ int err;
+
+ if (bh) {
+ BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+ err = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (unlikely(err))
+ return err;
+ }
+ err = ext4_mark_inode_dirty(handle, inode);
+ if (unlikely(err))
+ return err;
+ /*
+ * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
+ * moment, get_block can be called only for blocks inside i_size since
+ * page cache has been already dropped and writes are blocked by
+ * i_rwsem. So we can safely drop the i_data_sem here.
+ */
+ BUG_ON(EXT4_JOURNAL(inode) == NULL);
+ ext4_discard_preallocations(inode);
+ up_write(&EXT4_I(inode)->i_data_sem);
+ *dropped = 1;
+ return 0;
+}
+
+/*
+ * Truncate transactions can be complex and absolutely huge. So we need to
+ * be able to restart the transaction at a convenient checkpoint to make
+ * sure we don't overflow the journal.
+ *
+ * Try to extend this transaction for the purposes of truncation. If
+ * extend fails, we restart transaction.
+ */
+static int ext4_ind_truncate_ensure_credits(handle_t *handle,
+ struct inode *inode,
+ struct buffer_head *bh,
+ int revoke_creds)
+{
+ int ret;
+ int dropped = 0;
+
+ ret = ext4_journal_ensure_credits_fn(handle, EXT4_RESERVE_TRANS_BLOCKS,
+ ext4_blocks_for_truncate(inode), revoke_creds,
+ ext4_ind_trunc_restart_fn(handle, inode, bh, &dropped));
+ if (dropped)
+ down_write(&EXT4_I(inode)->i_data_sem);
+ if (ret <= 0)
+ return ret;
+ if (bh) {
+ BUFFER_TRACE(bh, "retaking write access");
+ ret = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (unlikely(ret))
+ return ret;
+ }
+ return 0;
+}
+
+/*
+ * Probably it should be a library function... search for first non-zero word
+ * or memcmp with zero_page, whatever is better for particular architecture.
+ * Linus?
+ */
+static inline int all_zeroes(__le32 *p, __le32 *q)
+{
+ while (p < q)
+ if (*p++)
+ return 0;
+ return 1;
+}
+
+/**
+ * ext4_find_shared - find the indirect blocks for partial truncation.
+ * @inode: inode in question
+ * @depth: depth of the affected branch
+ * @offsets: offsets of pointers in that branch (see ext4_block_to_path)
+ * @chain: place to store the pointers to partial indirect blocks
+ * @top: place to the (detached) top of branch
+ *
+ * This is a helper function used by ext4_truncate().
+ *
+ * When we do truncate() we may have to clean the ends of several
+ * indirect blocks but leave the blocks themselves alive. Block is
+ * partially truncated if some data below the new i_size is referred
+ * from it (and it is on the path to the first completely truncated
+ * data block, indeed). We have to free the top of that path along
+ * with everything to the right of the path. Since no allocation
+ * past the truncation point is possible until ext4_truncate()
+ * finishes, we may safely do the latter, but top of branch may
+ * require special attention - pageout below the truncation point
+ * might try to populate it.
+ *
+ * We atomically detach the top of branch from the tree, store the
+ * block number of its root in *@top, pointers to buffer_heads of
+ * partially truncated blocks - in @chain[].bh and pointers to
+ * their last elements that should not be removed - in
+ * @chain[].p. Return value is the pointer to last filled element
+ * of @chain.
+ *
+ * The work left to caller to do the actual freeing of subtrees:
+ * a) free the subtree starting from *@top
+ * b) free the subtrees whose roots are stored in
+ * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
+ * c) free the subtrees growing from the inode past the @chain[0].
+ * (no partially truncated stuff there). */
+
+static Indirect *ext4_find_shared(struct inode *inode, int depth,
+ ext4_lblk_t offsets[4], Indirect chain[4],
+ __le32 *top)
+{
+ Indirect *partial, *p;
+ int k, err;
+
+ *top = 0;
+ /* Make k index the deepest non-null offset + 1 */
+ for (k = depth; k > 1 && !offsets[k-1]; k--)
+ ;
+ partial = ext4_get_branch(inode, k, offsets, chain, &err);
+ /* Writer: pointers */
+ if (!partial)
+ partial = chain + k-1;
+ /*
+ * If the branch acquired continuation since we've looked at it -
+ * fine, it should all survive and (new) top doesn't belong to us.
+ */
+ if (!partial->key && *partial->p)
+ /* Writer: end */
+ goto no_top;
+ for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
+ ;
+ /*
+ * OK, we've found the last block that must survive. The rest of our
+ * branch should be detached before unlocking. However, if that rest
+ * of branch is all ours and does not grow immediately from the inode
+ * it's easier to cheat and just decrement partial->p.
+ */
+ if (p == chain + k - 1 && p > chain) {
+ p->p--;
+ } else {
+ *top = *p->p;
+ /* Nope, don't do this in ext4. Must leave the tree intact */
+#if 0
+ *p->p = 0;
+#endif
+ }
+ /* Writer: end */
+
+ while (partial > p) {
+ brelse(partial->bh);
+ partial--;
+ }
+no_top:
+ return partial;
+}
+
+/*
+ * Zero a number of block pointers in either an inode or an indirect block.
+ * If we restart the transaction we must again get write access to the
+ * indirect block for further modification.
+ *
+ * We release `count' blocks on disk, but (last - first) may be greater
+ * than `count' because there can be holes in there.
+ *
+ * Return 0 on success, 1 on invalid block range
+ * and < 0 on fatal error.
+ */
+static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh,
+ ext4_fsblk_t block_to_free,
+ unsigned long count, __le32 *first,
+ __le32 *last)
+{
+ __le32 *p;
+ int flags = EXT4_FREE_BLOCKS_VALIDATED;
+ int err;
+
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
+ ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
+ flags |= EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_METADATA;
+ else if (ext4_should_journal_data(inode))
+ flags |= EXT4_FREE_BLOCKS_FORGET;
+
+ if (!ext4_inode_block_valid(inode, block_to_free, count)) {
+ EXT4_ERROR_INODE(inode, "attempt to clear invalid "
+ "blocks %llu len %lu",
+ (unsigned long long) block_to_free, count);
+ return 1;
+ }
+
+ err = ext4_ind_truncate_ensure_credits(handle, inode, bh,
+ ext4_free_data_revoke_credits(inode, count));
+ if (err < 0)
+ goto out_err;
+
+ for (p = first; p < last; p++)
+ *p = 0;
+
+ ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);
+ return 0;
+out_err:
+ ext4_std_error(inode->i_sb, err);
+ return err;
+}
+
+/**
+ * ext4_free_data - free a list of data blocks
+ * @handle: handle for this transaction
+ * @inode: inode we are dealing with
+ * @this_bh: indirect buffer_head which contains *@first and *@last
+ * @first: array of block numbers
+ * @last: points immediately past the end of array
+ *
+ * We are freeing all blocks referred from that array (numbers are stored as
+ * little-endian 32-bit) and updating @inode->i_blocks appropriately.
+ *
+ * We accumulate contiguous runs of blocks to free. Conveniently, if these
+ * blocks are contiguous then releasing them at one time will only affect one
+ * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
+ * actually use a lot of journal space.
+ *
+ * @this_bh will be %NULL if @first and @last point into the inode's direct
+ * block pointers.
+ */
+static void ext4_free_data(handle_t *handle, struct inode *inode,
+ struct buffer_head *this_bh,
+ __le32 *first, __le32 *last)
+{
+ ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */
+ unsigned long count = 0; /* Number of blocks in the run */
+ __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
+ corresponding to
+ block_to_free */
+ ext4_fsblk_t nr; /* Current block # */
+ __le32 *p; /* Pointer into inode/ind
+ for current block */
+ int err = 0;
+
+ if (this_bh) { /* For indirect block */
+ BUFFER_TRACE(this_bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, inode->i_sb,
+ this_bh, EXT4_JTR_NONE);
+ /* Important: if we can't update the indirect pointers
+ * to the blocks, we can't free them. */
+ if (err)
+ return;
+ }
+
+ for (p = first; p < last; p++) {
+ nr = le32_to_cpu(*p);
+ if (nr) {
+ /* accumulate blocks to free if they're contiguous */
+ if (count == 0) {
+ block_to_free = nr;
+ block_to_free_p = p;
+ count = 1;
+ } else if (nr == block_to_free + count) {
+ count++;
+ } else {
+ err = ext4_clear_blocks(handle, inode, this_bh,
+ block_to_free, count,
+ block_to_free_p, p);
+ if (err)
+ break;
+ block_to_free = nr;
+ block_to_free_p = p;
+ count = 1;
+ }
+ }
+ }
+
+ if (!err && count > 0)
+ err = ext4_clear_blocks(handle, inode, this_bh, block_to_free,
+ count, block_to_free_p, p);
+ if (err < 0)
+ /* fatal error */
+ return;
+
+ if (this_bh) {
+ BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
+
+ /*
+ * The buffer head should have an attached journal head at this
+ * point. However, if the data is corrupted and an indirect
+ * block pointed to itself, it would have been detached when
+ * the block was cleared. Check for this instead of OOPSing.
+ */
+ if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
+ ext4_handle_dirty_metadata(handle, inode, this_bh);
+ else
+ EXT4_ERROR_INODE(inode,
+ "circular indirect block detected at "
+ "block %llu",
+ (unsigned long long) this_bh->b_blocknr);
+ }
+}
+
+/**
+ * ext4_free_branches - free an array of branches
+ * @handle: JBD handle for this transaction
+ * @inode: inode we are dealing with
+ * @parent_bh: the buffer_head which contains *@first and *@last
+ * @first: array of block numbers
+ * @last: pointer immediately past the end of array
+ * @depth: depth of the branches to free
+ *
+ * We are freeing all blocks referred from these branches (numbers are
+ * stored as little-endian 32-bit) and updating @inode->i_blocks
+ * appropriately.
+ */
+static void ext4_free_branches(handle_t *handle, struct inode *inode,
+ struct buffer_head *parent_bh,
+ __le32 *first, __le32 *last, int depth)
+{
+ ext4_fsblk_t nr;
+ __le32 *p;
+
+ if (ext4_handle_is_aborted(handle))
+ return;
+
+ if (depth--) {
+ struct buffer_head *bh;
+ int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+ p = last;
+ while (--p >= first) {
+ nr = le32_to_cpu(*p);
+ if (!nr)
+ continue; /* A hole */
+
+ if (!ext4_inode_block_valid(inode, nr, 1)) {
+ EXT4_ERROR_INODE(inode,
+ "invalid indirect mapped "
+ "block %lu (level %d)",
+ (unsigned long) nr, depth);
+ break;
+ }
+
+ /* Go read the buffer for the next level down */
+ bh = ext4_sb_bread_nofail(inode->i_sb, nr);
+
+ /*
+ * A read failure? Report error and clear slot
+ * (should be rare).
+ */
+ if (IS_ERR(bh)) {
+ ext4_error_inode_block(inode, nr, -PTR_ERR(bh),
+ "Read failure");
+ continue;
+ }
+
+ /* This zaps the entire block. Bottom up. */
+ BUFFER_TRACE(bh, "free child branches");
+ ext4_free_branches(handle, inode, bh,
+ (__le32 *) bh->b_data,
+ (__le32 *) bh->b_data + addr_per_block,
+ depth);
+ brelse(bh);
+
+ /*
+ * Everything below this pointer has been
+ * released. Now let this top-of-subtree go.
+ *
+ * We want the freeing of this indirect block to be
+ * atomic in the journal with the updating of the
+ * bitmap block which owns it. So make some room in
+ * the journal.
+ *
+ * We zero the parent pointer *after* freeing its
+ * pointee in the bitmaps, so if extend_transaction()
+ * for some reason fails to put the bitmap changes and
+ * the release into the same transaction, recovery
+ * will merely complain about releasing a free block,
+ * rather than leaking blocks.
+ */
+ if (ext4_handle_is_aborted(handle))
+ return;
+ if (ext4_ind_truncate_ensure_credits(handle, inode,
+ NULL,
+ ext4_free_metadata_revoke_credits(
+ inode->i_sb, 1)) < 0)
+ return;
+
+ /*
+ * The forget flag here is critical because if
+ * we are journaling (and not doing data
+ * journaling), we have to make sure a revoke
+ * record is written to prevent the journal
+ * replay from overwriting the (former)
+ * indirect block if it gets reallocated as a
+ * data block. This must happen in the same
+ * transaction where the data blocks are
+ * actually freed.
+ */
+ ext4_free_blocks(handle, inode, NULL, nr, 1,
+ EXT4_FREE_BLOCKS_METADATA|
+ EXT4_FREE_BLOCKS_FORGET);
+
+ if (parent_bh) {
+ /*
+ * The block which we have just freed is
+ * pointed to by an indirect block: journal it
+ */
+ BUFFER_TRACE(parent_bh, "get_write_access");
+ if (!ext4_journal_get_write_access(handle,
+ inode->i_sb, parent_bh,
+ EXT4_JTR_NONE)) {
+ *p = 0;
+ BUFFER_TRACE(parent_bh,
+ "call ext4_handle_dirty_metadata");
+ ext4_handle_dirty_metadata(handle,
+ inode,
+ parent_bh);
+ }
+ }
+ }
+ } else {
+ /* We have reached the bottom of the tree. */
+ BUFFER_TRACE(parent_bh, "free data blocks");
+ ext4_free_data(handle, inode, parent_bh, first, last);
+ }
+}
+
+void ext4_ind_truncate(handle_t *handle, struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ __le32 *i_data = ei->i_data;
+ int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+ ext4_lblk_t offsets[4];
+ Indirect chain[4];
+ Indirect *partial;
+ __le32 nr = 0;
+ int n = 0;
+ ext4_lblk_t last_block, max_block;
+ unsigned blocksize = inode->i_sb->s_blocksize;
+
+ last_block = (inode->i_size + blocksize-1)
+ >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+ max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
+ >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+
+ if (last_block != max_block) {
+ n = ext4_block_to_path(inode, last_block, offsets, NULL);
+ if (n == 0)
+ return;
+ }
+
+ ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
+
+ /*
+ * The orphan list entry will now protect us from any crash which
+ * occurs before the truncate completes, so it is now safe to propagate
+ * the new, shorter inode size (held for now in i_size) into the
+ * on-disk inode. We do this via i_disksize, which is the value which
+ * ext4 *really* writes onto the disk inode.
+ */
+ ei->i_disksize = inode->i_size;
+
+ if (last_block == max_block) {
+ /*
+ * It is unnecessary to free any data blocks if last_block is
+ * equal to the indirect block limit.
+ */
+ return;
+ } else if (n == 1) { /* direct blocks */
+ ext4_free_data(handle, inode, NULL, i_data+offsets[0],
+ i_data + EXT4_NDIR_BLOCKS);
+ goto do_indirects;
+ }
+
+ partial = ext4_find_shared(inode, n, offsets, chain, &nr);
+ /* Kill the top of shared branch (not detached) */
+ if (nr) {
+ if (partial == chain) {
+ /* Shared branch grows from the inode */
+ ext4_free_branches(handle, inode, NULL,
+ &nr, &nr+1, (chain+n-1) - partial);
+ *partial->p = 0;
+ /*
+ * We mark the inode dirty prior to restart,
+ * and prior to stop. No need for it here.
+ */
+ } else {
+ /* Shared branch grows from an indirect block */
+ BUFFER_TRACE(partial->bh, "get_write_access");
+ ext4_free_branches(handle, inode, partial->bh,
+ partial->p,
+ partial->p+1, (chain+n-1) - partial);
+ }
+ }
+ /* Clear the ends of indirect blocks on the shared branch */
+ while (partial > chain) {
+ ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
+ (__le32*)partial->bh->b_data+addr_per_block,
+ (chain+n-1) - partial);
+ BUFFER_TRACE(partial->bh, "call brelse");
+ brelse(partial->bh);
+ partial--;
+ }
+do_indirects:
+ /* Kill the remaining (whole) subtrees */
+ switch (offsets[0]) {
+ default:
+ nr = i_data[EXT4_IND_BLOCK];
+ if (nr) {
+ ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
+ i_data[EXT4_IND_BLOCK] = 0;
+ }
+ fallthrough;
+ case EXT4_IND_BLOCK:
+ nr = i_data[EXT4_DIND_BLOCK];
+ if (nr) {
+ ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
+ i_data[EXT4_DIND_BLOCK] = 0;
+ }
+ fallthrough;
+ case EXT4_DIND_BLOCK:
+ nr = i_data[EXT4_TIND_BLOCK];
+ if (nr) {
+ ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
+ i_data[EXT4_TIND_BLOCK] = 0;
+ }
+ fallthrough;
+ case EXT4_TIND_BLOCK:
+ ;
+ }
+}
+
+/**
+ * ext4_ind_remove_space - remove space from the range
+ * @handle: JBD handle for this transaction
+ * @inode: inode we are dealing with
+ * @start: First block to remove
+ * @end: One block after the last block to remove (exclusive)
+ *
+ * Free the blocks in the defined range (end is exclusive endpoint of
+ * range). This is used by ext4_punch_hole().
+ */
+int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
+ ext4_lblk_t start, ext4_lblk_t end)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ __le32 *i_data = ei->i_data;
+ int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+ ext4_lblk_t offsets[4], offsets2[4];
+ Indirect chain[4], chain2[4];
+ Indirect *partial, *partial2;
+ Indirect *p = NULL, *p2 = NULL;
+ ext4_lblk_t max_block;
+ __le32 nr = 0, nr2 = 0;
+ int n = 0, n2 = 0;
+ unsigned blocksize = inode->i_sb->s_blocksize;
+
+ max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
+ >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+ if (end >= max_block)
+ end = max_block;
+ if ((start >= end) || (start > max_block))
+ return 0;
+
+ n = ext4_block_to_path(inode, start, offsets, NULL);
+ n2 = ext4_block_to_path(inode, end, offsets2, NULL);
+
+ BUG_ON(n > n2);
+
+ if ((n == 1) && (n == n2)) {
+ /* We're punching only within direct block range */
+ ext4_free_data(handle, inode, NULL, i_data + offsets[0],
+ i_data + offsets2[0]);
+ return 0;
+ } else if (n2 > n) {
+ /*
+ * Start and end are on a different levels so we're going to
+ * free partial block at start, and partial block at end of
+ * the range. If there are some levels in between then
+ * do_indirects label will take care of that.
+ */
+
+ if (n == 1) {
+ /*
+ * Start is at the direct block level, free
+ * everything to the end of the level.
+ */
+ ext4_free_data(handle, inode, NULL, i_data + offsets[0],
+ i_data + EXT4_NDIR_BLOCKS);
+ goto end_range;
+ }
+
+
+ partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);
+ if (nr) {
+ if (partial == chain) {
+ /* Shared branch grows from the inode */
+ ext4_free_branches(handle, inode, NULL,
+ &nr, &nr+1, (chain+n-1) - partial);
+ *partial->p = 0;
+ } else {
+ /* Shared branch grows from an indirect block */
+ BUFFER_TRACE(partial->bh, "get_write_access");
+ ext4_free_branches(handle, inode, partial->bh,
+ partial->p,
+ partial->p+1, (chain+n-1) - partial);
+ }
+ }
+
+ /*
+ * Clear the ends of indirect blocks on the shared branch
+ * at the start of the range
+ */
+ while (partial > chain) {
+ ext4_free_branches(handle, inode, partial->bh,
+ partial->p + 1,
+ (__le32 *)partial->bh->b_data+addr_per_block,
+ (chain+n-1) - partial);
+ partial--;
+ }
+
+end_range:
+ partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
+ if (nr2) {
+ if (partial2 == chain2) {
+ /*
+ * Remember, end is exclusive so here we're at
+ * the start of the next level we're not going
+ * to free. Everything was covered by the start
+ * of the range.
+ */
+ goto do_indirects;
+ }
+ } else {
+ /*
+ * ext4_find_shared returns Indirect structure which
+ * points to the last element which should not be
+ * removed by truncate. But this is end of the range
+ * in punch_hole so we need to point to the next element
+ */
+ partial2->p++;
+ }
+
+ /*
+ * Clear the ends of indirect blocks on the shared branch
+ * at the end of the range
+ */
+ while (partial2 > chain2) {
+ ext4_free_branches(handle, inode, partial2->bh,
+ (__le32 *)partial2->bh->b_data,
+ partial2->p,
+ (chain2+n2-1) - partial2);
+ partial2--;
+ }
+ goto do_indirects;
+ }
+
+ /* Punch happened within the same level (n == n2) */
+ partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);
+ partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
+
+ /* Free top, but only if partial2 isn't its subtree. */
+ if (nr) {
+ int level = min(partial - chain, partial2 - chain2);
+ int i;
+ int subtree = 1;
+
+ for (i = 0; i <= level; i++) {
+ if (offsets[i] != offsets2[i]) {
+ subtree = 0;
+ break;
+ }
+ }
+
+ if (!subtree) {
+ if (partial == chain) {
+ /* Shared branch grows from the inode */
+ ext4_free_branches(handle, inode, NULL,
+ &nr, &nr+1,
+ (chain+n-1) - partial);
+ *partial->p = 0;
+ } else {
+ /* Shared branch grows from an indirect block */
+ BUFFER_TRACE(partial->bh, "get_write_access");
+ ext4_free_branches(handle, inode, partial->bh,
+ partial->p,
+ partial->p+1,
+ (chain+n-1) - partial);
+ }
+ }
+ }
+
+ if (!nr2) {
+ /*
+ * ext4_find_shared returns Indirect structure which
+ * points to the last element which should not be
+ * removed by truncate. But this is end of the range
+ * in punch_hole so we need to point to the next element
+ */
+ partial2->p++;
+ }
+
+ while (partial > chain || partial2 > chain2) {
+ int depth = (chain+n-1) - partial;
+ int depth2 = (chain2+n2-1) - partial2;
+
+ if (partial > chain && partial2 > chain2 &&
+ partial->bh->b_blocknr == partial2->bh->b_blocknr) {
+ /*
+ * We've converged on the same block. Clear the range,
+ * then we're done.
+ */
+ ext4_free_branches(handle, inode, partial->bh,
+ partial->p + 1,
+ partial2->p,
+ (chain+n-1) - partial);
+ goto cleanup;
+ }
+
+ /*
+ * The start and end partial branches may not be at the same
+ * level even though the punch happened within one level. So, we
+ * give them a chance to arrive at the same level, then walk
+ * them in step with each other until we converge on the same
+ * block.
+ */
+ if (partial > chain && depth <= depth2) {
+ ext4_free_branches(handle, inode, partial->bh,
+ partial->p + 1,
+ (__le32 *)partial->bh->b_data+addr_per_block,
+ (chain+n-1) - partial);
+ partial--;
+ }
+ if (partial2 > chain2 && depth2 <= depth) {
+ ext4_free_branches(handle, inode, partial2->bh,
+ (__le32 *)partial2->bh->b_data,
+ partial2->p,
+ (chain2+n2-1) - partial2);
+ partial2--;
+ }
+ }
+
+cleanup:
+ while (p && p > chain) {
+ BUFFER_TRACE(p->bh, "call brelse");
+ brelse(p->bh);
+ p--;
+ }
+ while (p2 && p2 > chain2) {
+ BUFFER_TRACE(p2->bh, "call brelse");
+ brelse(p2->bh);
+ p2--;
+ }
+ return 0;
+
+do_indirects:
+ /* Kill the remaining (whole) subtrees */
+ switch (offsets[0]) {
+ default:
+ if (++n >= n2)
+ break;
+ nr = i_data[EXT4_IND_BLOCK];
+ if (nr) {
+ ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
+ i_data[EXT4_IND_BLOCK] = 0;
+ }
+ fallthrough;
+ case EXT4_IND_BLOCK:
+ if (++n >= n2)
+ break;
+ nr = i_data[EXT4_DIND_BLOCK];
+ if (nr) {
+ ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
+ i_data[EXT4_DIND_BLOCK] = 0;
+ }
+ fallthrough;
+ case EXT4_DIND_BLOCK:
+ if (++n >= n2)
+ break;
+ nr = i_data[EXT4_TIND_BLOCK];
+ if (nr) {
+ ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
+ i_data[EXT4_TIND_BLOCK] = 0;
+ }
+ fallthrough;
+ case EXT4_TIND_BLOCK:
+ ;
+ }
+ goto cleanup;
+}
new file mode 100644
@@ -0,0 +1,1982 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (c) 2012 Taobao.
+ * Written by Tao Ma <boyu.mt@taobao.com>
+ */
+
+#include <linux/iomap.h>
+#include <linux/fiemap.h>
+#include <linux/namei.h>
+#include <linux/iversion.h>
+#include <linux/sched/mm.h>
+
+#include "ext4_jbd2.h"
+#include "ext4.h"
+#include "xattr.h"
+#include "truncate.h"
+
+#define EXT4_XATTR_SYSTEM_DATA "data"
+#define EXT4_MIN_INLINE_DATA_SIZE ((sizeof(__le32) * EXT4_N_BLOCKS))
+#define EXT4_INLINE_DOTDOT_OFFSET 2
+#define EXT4_INLINE_DOTDOT_SIZE 4
+
+
+static int ext4_da_convert_inline_data_to_extent(struct address_space *mapping,
+ struct inode *inode,
+ void **fsdata);
+
+static int ext4_get_inline_size(struct inode *inode)
+{
+ if (EXT4_I(inode)->i_inline_off)
+ return EXT4_I(inode)->i_inline_size;
+
+ return 0;
+}
+
+static int get_max_inline_xattr_value_size(struct inode *inode,
+ struct ext4_iloc *iloc)
+{
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_xattr_entry *entry;
+ struct ext4_inode *raw_inode;
+ void *end;
+ int free, min_offs;
+
+ if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
+ return 0;
+
+ min_offs = EXT4_SB(inode->i_sb)->s_inode_size -
+ EXT4_GOOD_OLD_INODE_SIZE -
+ EXT4_I(inode)->i_extra_isize -
+ sizeof(struct ext4_xattr_ibody_header);
+
+ /*
+ * We need to subtract another sizeof(__u32) since an in-inode xattr
+ * needs an empty 4 bytes to indicate the gap between the xattr entry
+ * and the name/value pair.
+ */
+ if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
+ return EXT4_XATTR_SIZE(min_offs -
+ EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA)) -
+ EXT4_XATTR_ROUND - sizeof(__u32));
+
+ raw_inode = ext4_raw_inode(iloc);
+ header = IHDR(inode, raw_inode);
+ entry = IFIRST(header);
+ end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+
+ /* Compute min_offs. */
+ while (!IS_LAST_ENTRY(entry)) {
+ void *next = EXT4_XATTR_NEXT(entry);
+
+ if (next >= end) {
+ EXT4_ERROR_INODE(inode,
+ "corrupt xattr in inline inode");
+ return 0;
+ }
+ if (!entry->e_value_inum && entry->e_value_size) {
+ size_t offs = le16_to_cpu(entry->e_value_offs);
+ if (offs < min_offs)
+ min_offs = offs;
+ }
+ entry = next;
+ }
+ free = min_offs -
+ ((void *)entry - (void *)IFIRST(header)) - sizeof(__u32);
+
+ if (EXT4_I(inode)->i_inline_off) {
+ entry = (struct ext4_xattr_entry *)
+ ((void *)raw_inode + EXT4_I(inode)->i_inline_off);
+
+ free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size));
+ goto out;
+ }
+
+ free -= EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA));
+
+ if (free > EXT4_XATTR_ROUND)
+ free = EXT4_XATTR_SIZE(free - EXT4_XATTR_ROUND);
+ else
+ free = 0;
+
+out:
+ return free;
+}
+
+/*
+ * Get the maximum size we now can store in an inode.
+ * If we can't find the space for a xattr entry, don't use the space
+ * of the extents since we have no space to indicate the inline data.
+ */
+int ext4_get_max_inline_size(struct inode *inode)
+{
+ int error, max_inline_size;
+ struct ext4_iloc iloc;
+
+ if (EXT4_I(inode)->i_extra_isize == 0)
+ return 0;
+
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error) {
+ ext4_error_inode_err(inode, __func__, __LINE__, 0, -error,
+ "can't get inode location %lu",
+ inode->i_ino);
+ return 0;
+ }
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ max_inline_size = get_max_inline_xattr_value_size(inode, &iloc);
+ up_read(&EXT4_I(inode)->xattr_sem);
+
+ brelse(iloc.bh);
+
+ if (!max_inline_size)
+ return 0;
+
+ return max_inline_size + EXT4_MIN_INLINE_DATA_SIZE;
+}
+
+/*
+ * this function does not take xattr_sem, which is OK because it is
+ * currently only used in a code path coming form ext4_iget, before
+ * the new inode has been unlocked
+ */
+int ext4_find_inline_data_nolock(struct inode *inode)
+{
+ struct ext4_xattr_ibody_find is = {
+ .s = { .not_found = -ENODATA, },
+ };
+ struct ext4_xattr_info i = {
+ .name_index = EXT4_XATTR_INDEX_SYSTEM,
+ .name = EXT4_XATTR_SYSTEM_DATA,
+ };
+ int error;
+
+ if (EXT4_I(inode)->i_extra_isize == 0)
+ return 0;
+
+ error = ext4_get_inode_loc(inode, &is.iloc);
+ if (error)
+ return error;
+
+ error = ext4_xattr_ibody_find(inode, &i, &is);
+ if (error)
+ goto out;
+
+ if (!is.s.not_found) {
+ if (is.s.here->e_value_inum) {
+ EXT4_ERROR_INODE(inode, "inline data xattr refers "
+ "to an external xattr inode");
+ error = -EFSCORRUPTED;
+ goto out;
+ }
+ EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here -
+ (void *)ext4_raw_inode(&is.iloc));
+ EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE +
+ le32_to_cpu(is.s.here->e_value_size);
+ }
+out:
+ brelse(is.iloc.bh);
+ return error;
+}
+
+static int ext4_read_inline_data(struct inode *inode, void *buffer,
+ unsigned int len,
+ struct ext4_iloc *iloc)
+{
+ struct ext4_xattr_entry *entry;
+ struct ext4_xattr_ibody_header *header;
+ int cp_len = 0;
+ struct ext4_inode *raw_inode;
+
+ if (!len)
+ return 0;
+
+ BUG_ON(len > EXT4_I(inode)->i_inline_size);
+
+ cp_len = min_t(unsigned int, len, EXT4_MIN_INLINE_DATA_SIZE);
+
+ raw_inode = ext4_raw_inode(iloc);
+ memcpy(buffer, (void *)(raw_inode->i_block), cp_len);
+
+ len -= cp_len;
+ buffer += cp_len;
+
+ if (!len)
+ goto out;
+
+ header = IHDR(inode, raw_inode);
+ entry = (struct ext4_xattr_entry *)((void *)raw_inode +
+ EXT4_I(inode)->i_inline_off);
+ len = min_t(unsigned int, len,
+ (unsigned int)le32_to_cpu(entry->e_value_size));
+
+ memcpy(buffer,
+ (void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs), len);
+ cp_len += len;
+
+out:
+ return cp_len;
+}
+
+/*
+ * write the buffer to the inline inode.
+ * If 'create' is set, we don't need to do the extra copy in the xattr
+ * value since it is already handled by ext4_xattr_ibody_set.
+ * That saves us one memcpy.
+ */
+static void ext4_write_inline_data(struct inode *inode, struct ext4_iloc *iloc,
+ void *buffer, loff_t pos, unsigned int len)
+{
+ struct ext4_xattr_entry *entry;
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_inode *raw_inode;
+ int cp_len = 0;
+
+ if (unlikely(ext4_emergency_state(inode->i_sb)))
+ return;
+
+ BUG_ON(!EXT4_I(inode)->i_inline_off);
+ BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);
+
+ raw_inode = ext4_raw_inode(iloc);
+ buffer += pos;
+
+ if (pos < EXT4_MIN_INLINE_DATA_SIZE) {
+ cp_len = pos + len > EXT4_MIN_INLINE_DATA_SIZE ?
+ EXT4_MIN_INLINE_DATA_SIZE - pos : len;
+ memcpy((void *)raw_inode->i_block + pos, buffer, cp_len);
+
+ len -= cp_len;
+ buffer += cp_len;
+ pos += cp_len;
+ }
+
+ if (!len)
+ return;
+
+ pos -= EXT4_MIN_INLINE_DATA_SIZE;
+ header = IHDR(inode, raw_inode);
+ entry = (struct ext4_xattr_entry *)((void *)raw_inode +
+ EXT4_I(inode)->i_inline_off);
+
+ memcpy((void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs) + pos,
+ buffer, len);
+}
+
+static int ext4_create_inline_data(handle_t *handle,
+ struct inode *inode, unsigned len)
+{
+ int error;
+ void *value = NULL;
+ struct ext4_xattr_ibody_find is = {
+ .s = { .not_found = -ENODATA, },
+ };
+ struct ext4_xattr_info i = {
+ .name_index = EXT4_XATTR_INDEX_SYSTEM,
+ .name = EXT4_XATTR_SYSTEM_DATA,
+ };
+
+ error = ext4_get_inode_loc(inode, &is.iloc);
+ if (error)
+ return error;
+
+ BUFFER_TRACE(is.iloc.bh, "get_write_access");
+ error = ext4_journal_get_write_access(handle, inode->i_sb, is.iloc.bh,
+ EXT4_JTR_NONE);
+ if (error)
+ goto out;
+
+ if (len > EXT4_MIN_INLINE_DATA_SIZE) {
+ value = EXT4_ZERO_XATTR_VALUE;
+ len -= EXT4_MIN_INLINE_DATA_SIZE;
+ } else {
+ value = "";
+ len = 0;
+ }
+
+ /* Insert the xttr entry. */
+ i.value = value;
+ i.value_len = len;
+
+ error = ext4_xattr_ibody_find(inode, &i, &is);
+ if (error)
+ goto out;
+
+ if (!is.s.not_found) {
+ EXT4_ERROR_INODE(inode, "unexpected inline data xattr");
+ error = -EFSCORRUPTED;
+ goto out;
+ }
+
+ error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+ if (error) {
+ if (error == -ENOSPC)
+ ext4_clear_inode_state(inode,
+ EXT4_STATE_MAY_INLINE_DATA);
+ goto out;
+ }
+
+ memset((void *)ext4_raw_inode(&is.iloc)->i_block,
+ 0, EXT4_MIN_INLINE_DATA_SIZE);
+
+ EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here -
+ (void *)ext4_raw_inode(&is.iloc));
+ EXT4_I(inode)->i_inline_size = len + EXT4_MIN_INLINE_DATA_SIZE;
+ ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
+ ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA);
+ get_bh(is.iloc.bh);
+ error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
+
+out:
+ brelse(is.iloc.bh);
+ return error;
+}
+
+static int ext4_update_inline_data(handle_t *handle, struct inode *inode,
+ unsigned int len)
+{
+ int error;
+ void *value = NULL;
+ struct ext4_xattr_ibody_find is = {
+ .s = { .not_found = -ENODATA, },
+ };
+ struct ext4_xattr_info i = {
+ .name_index = EXT4_XATTR_INDEX_SYSTEM,
+ .name = EXT4_XATTR_SYSTEM_DATA,
+ };
+
+ /* If the old space is ok, write the data directly. */
+ if (len <= EXT4_I(inode)->i_inline_size)
+ return 0;
+
+ error = ext4_get_inode_loc(inode, &is.iloc);
+ if (error)
+ return error;
+
+ error = ext4_xattr_ibody_find(inode, &i, &is);
+ if (error)
+ goto out;
+
+ if (is.s.not_found) {
+ EXT4_ERROR_INODE(inode, "missing inline data xattr");
+ error = -EFSCORRUPTED;
+ goto out;
+ }
+
+ len -= EXT4_MIN_INLINE_DATA_SIZE;
+ value = kzalloc(len, GFP_NOFS);
+ if (!value) {
+ error = -ENOMEM;
+ goto out;
+ }
+
+ error = ext4_xattr_ibody_get(inode, i.name_index, i.name,
+ value, len);
+ if (error < 0)
+ goto out;
+
+ BUFFER_TRACE(is.iloc.bh, "get_write_access");
+ error = ext4_journal_get_write_access(handle, inode->i_sb, is.iloc.bh,
+ EXT4_JTR_NONE);
+ if (error)
+ goto out;
+
+ /* Update the xattr entry. */
+ i.value = value;
+ i.value_len = len;
+
+ error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+ if (error)
+ goto out;
+
+ EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here -
+ (void *)ext4_raw_inode(&is.iloc));
+ EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE +
+ le32_to_cpu(is.s.here->e_value_size);
+ ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+ get_bh(is.iloc.bh);
+ error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
+
+out:
+ kfree(value);
+ brelse(is.iloc.bh);
+ return error;
+}
+
+static int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
+ loff_t len)
+{
+ int ret, size, no_expand;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
+ return -ENOSPC;
+
+ size = ext4_get_max_inline_size(inode);
+ if (size < len)
+ return -ENOSPC;
+
+ ext4_write_lock_xattr(inode, &no_expand);
+
+ if (ei->i_inline_off)
+ ret = ext4_update_inline_data(handle, inode, len);
+ else
+ ret = ext4_create_inline_data(handle, inode, len);
+
+ ext4_write_unlock_xattr(inode, &no_expand);
+ return ret;
+}
+
+static int ext4_destroy_inline_data_nolock(handle_t *handle,
+ struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_xattr_ibody_find is = {
+ .s = { .not_found = 0, },
+ };
+ struct ext4_xattr_info i = {
+ .name_index = EXT4_XATTR_INDEX_SYSTEM,
+ .name = EXT4_XATTR_SYSTEM_DATA,
+ .value = NULL,
+ .value_len = 0,
+ };
+ int error;
+
+ if (!ei->i_inline_off)
+ return 0;
+
+ error = ext4_get_inode_loc(inode, &is.iloc);
+ if (error)
+ return error;
+
+ error = ext4_xattr_ibody_find(inode, &i, &is);
+ if (error)
+ goto out;
+
+ BUFFER_TRACE(is.iloc.bh, "get_write_access");
+ error = ext4_journal_get_write_access(handle, inode->i_sb, is.iloc.bh,
+ EXT4_JTR_NONE);
+ if (error)
+ goto out;
+
+ error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+ if (error)
+ goto out;
+
+ memset((void *)ext4_raw_inode(&is.iloc)->i_block,
+ 0, EXT4_MIN_INLINE_DATA_SIZE);
+ memset(ei->i_data, 0, EXT4_MIN_INLINE_DATA_SIZE);
+
+ if (ext4_has_feature_extents(inode->i_sb)) {
+ if (S_ISDIR(inode->i_mode) ||
+ S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode)) {
+ ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);
+ ext4_ext_tree_init(handle, inode);
+ }
+ }
+ ext4_clear_inode_flag(inode, EXT4_INODE_INLINE_DATA);
+
+ get_bh(is.iloc.bh);
+ error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
+
+ EXT4_I(inode)->i_inline_off = 0;
+ EXT4_I(inode)->i_inline_size = 0;
+ ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+out:
+ brelse(is.iloc.bh);
+ if (error == -ENODATA)
+ error = 0;
+ return error;
+}
+
+static int ext4_read_inline_folio(struct inode *inode, struct folio *folio)
+{
+ void *kaddr;
+ int ret = 0;
+ size_t len;
+ struct ext4_iloc iloc;
+
+ BUG_ON(!folio_test_locked(folio));
+ BUG_ON(!ext4_has_inline_data(inode));
+ BUG_ON(folio->index);
+
+ if (!EXT4_I(inode)->i_inline_off) {
+ ext4_warning(inode->i_sb, "inode %lu doesn't have inline data.",
+ inode->i_ino);
+ goto out;
+ }
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ goto out;
+
+ len = min_t(size_t, ext4_get_inline_size(inode), i_size_read(inode));
+ BUG_ON(len > PAGE_SIZE);
+ kaddr = kmap_local_folio(folio, 0);
+ ret = ext4_read_inline_data(inode, kaddr, len, &iloc);
+ kaddr = folio_zero_tail(folio, len, kaddr + len);
+ kunmap_local(kaddr);
+ folio_mark_uptodate(folio);
+ brelse(iloc.bh);
+
+out:
+ return ret;
+}
+
+int ext4_readpage_inline(struct inode *inode, struct folio *folio)
+{
+ int ret = 0;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode)) {
+ up_read(&EXT4_I(inode)->xattr_sem);
+ return -EAGAIN;
+ }
+
+ /*
+ * Current inline data can only exist in the 1st page,
+ * So for all the other pages, just set them uptodate.
+ */
+ if (!folio->index)
+ ret = ext4_read_inline_folio(inode, folio);
+ else if (!folio_test_uptodate(folio)) {
+ folio_zero_segment(folio, 0, folio_size(folio));
+ folio_mark_uptodate(folio);
+ }
+
+ up_read(&EXT4_I(inode)->xattr_sem);
+
+ folio_unlock(folio);
+ return ret >= 0 ? 0 : ret;
+}
+
+static int ext4_convert_inline_data_to_extent(struct address_space *mapping,
+ struct inode *inode)
+{
+ int ret, needed_blocks, no_expand;
+ handle_t *handle = NULL;
+ int retries = 0, sem_held = 0;
+ struct folio *folio = NULL;
+ unsigned from, to;
+ struct ext4_iloc iloc;
+
+ if (!ext4_has_inline_data(inode)) {
+ /*
+ * clear the flag so that no new write
+ * will trap here again.
+ */
+ ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+ return 0;
+ }
+
+ needed_blocks = ext4_chunk_trans_extent(inode, 1);
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+retry:
+ handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ handle = NULL;
+ goto out;
+ }
+
+ /* We cannot recurse into the filesystem as the transaction is already
+ * started */
+ folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN | FGP_NOFS,
+ mapping_gfp_mask(mapping));
+ if (IS_ERR(folio)) {
+ ret = PTR_ERR(folio);
+ goto out_nofolio;
+ }
+
+ ext4_write_lock_xattr(inode, &no_expand);
+ sem_held = 1;
+ /* If some one has already done this for us, just exit. */
+ if (!ext4_has_inline_data(inode)) {
+ ret = 0;
+ goto out;
+ }
+
+ from = 0;
+ to = ext4_get_inline_size(inode);
+ if (!folio_test_uptodate(folio)) {
+ ret = ext4_read_inline_folio(inode, folio);
+ if (ret < 0)
+ goto out;
+ }
+
+ ext4_fc_track_inode(handle, inode);
+ ret = ext4_destroy_inline_data_nolock(handle, inode);
+ if (ret)
+ goto out;
+
+ if (ext4_should_dioread_nolock(inode)) {
+ ret = ext4_block_write_begin(handle, folio, from, to,
+ ext4_get_block_unwritten);
+ } else
+ ret = ext4_block_write_begin(handle, folio, from, to,
+ ext4_get_block);
+ clear_buffer_new(folio_buffers(folio));
+
+ if (!ret && ext4_should_journal_data(inode)) {
+ ret = ext4_walk_page_buffers(handle, inode,
+ folio_buffers(folio), from, to,
+ NULL, do_journal_get_write_access);
+ }
+
+ if (ret) {
+ folio_unlock(folio);
+ folio_put(folio);
+ folio = NULL;
+ ext4_orphan_add(handle, inode);
+ ext4_write_unlock_xattr(inode, &no_expand);
+ sem_held = 0;
+ ext4_journal_stop(handle);
+ handle = NULL;
+ ext4_truncate_failed_write(inode);
+ /*
+ * If truncate failed early the inode might
+ * still be on the orphan list; we need to
+ * make sure the inode is removed from the
+ * orphan list in that case.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(NULL, inode);
+ }
+
+ if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry;
+
+ if (folio)
+ block_commit_write(folio, from, to);
+out:
+ if (folio) {
+ folio_unlock(folio);
+ folio_put(folio);
+ }
+out_nofolio:
+ if (sem_held)
+ ext4_write_unlock_xattr(inode, &no_expand);
+ if (handle)
+ ext4_journal_stop(handle);
+ brelse(iloc.bh);
+ return ret;
+}
+
+/*
+ * Prepare the write for the inline data.
+ * If the data can be written into the inode, we just read
+ * the page and make it uptodate, and start the journal.
+ * Otherwise read the page, makes it dirty so that it can be
+ * handle in writepages(the i_disksize update is left to the
+ * normal ext4_da_write_end).
+ */
+int ext4_generic_write_inline_data(struct address_space *mapping,
+ struct inode *inode,
+ loff_t pos, unsigned len,
+ struct folio **foliop,
+ void **fsdata, bool da)
+{
+ int ret;
+ handle_t *handle;
+ struct folio *folio;
+ struct ext4_iloc iloc;
+ int retries = 0;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+retry_journal:
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out_release_bh;
+ }
+
+ ret = ext4_prepare_inline_data(handle, inode, pos + len);
+ if (ret && ret != -ENOSPC)
+ goto out_stop_journal;
+
+ if (ret == -ENOSPC) {
+ ext4_journal_stop(handle);
+ if (!da) {
+ brelse(iloc.bh);
+ /* Retry inside */
+ return ext4_convert_inline_data_to_extent(mapping, inode);
+ }
+
+ ret = ext4_da_convert_inline_data_to_extent(mapping, inode, fsdata);
+ if (ret == -ENOSPC &&
+ ext4_should_retry_alloc(inode->i_sb, &retries))
+ goto retry_journal;
+ goto out_release_bh;
+ }
+
+ folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN | FGP_NOFS,
+ mapping_gfp_mask(mapping));
+ if (IS_ERR(folio)) {
+ ret = PTR_ERR(folio);
+ goto out_stop_journal;
+ }
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ /* Someone else had converted it to extent */
+ if (!ext4_has_inline_data(inode)) {
+ ret = 0;
+ goto out_release_folio;
+ }
+
+ if (!folio_test_uptodate(folio)) {
+ ret = ext4_read_inline_folio(inode, folio);
+ if (ret < 0)
+ goto out_release_folio;
+ }
+
+ ret = ext4_journal_get_write_access(handle, inode->i_sb, iloc.bh, EXT4_JTR_NONE);
+ if (ret)
+ goto out_release_folio;
+ *foliop = folio;
+ up_read(&EXT4_I(inode)->xattr_sem);
+ brelse(iloc.bh);
+ return 1;
+
+out_release_folio:
+ up_read(&EXT4_I(inode)->xattr_sem);
+ folio_unlock(folio);
+ folio_put(folio);
+out_stop_journal:
+ ext4_journal_stop(handle);
+out_release_bh:
+ brelse(iloc.bh);
+ return ret;
+}
+
+/*
+ * Try to write data in the inode.
+ * If the inode has inline data, check whether the new write can be
+ * in the inode also. If not, create the page the handle, move the data
+ * to the page make it update and let the later codes create extent for it.
+ */
+int ext4_try_to_write_inline_data(struct address_space *mapping,
+ struct inode *inode,
+ loff_t pos, unsigned len,
+ struct folio **foliop)
+{
+ if (pos + len > ext4_get_max_inline_size(inode))
+ return ext4_convert_inline_data_to_extent(mapping, inode);
+ return ext4_generic_write_inline_data(mapping, inode, pos, len,
+ foliop, NULL, false);
+}
+
+int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
+ unsigned copied, struct folio *folio)
+{
+ handle_t *handle = ext4_journal_current_handle();
+ int no_expand;
+ void *kaddr;
+ struct ext4_iloc iloc;
+ int ret = 0, ret2;
+
+ if (unlikely(copied < len) && !folio_test_uptodate(folio))
+ copied = 0;
+
+ if (likely(copied)) {
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret) {
+ folio_unlock(folio);
+ folio_put(folio);
+ ext4_std_error(inode->i_sb, ret);
+ goto out;
+ }
+ ext4_write_lock_xattr(inode, &no_expand);
+ BUG_ON(!ext4_has_inline_data(inode));
+
+ /*
+ * ei->i_inline_off may have changed since
+ * ext4_write_begin() called
+ * ext4_try_to_write_inline_data()
+ */
+ (void) ext4_find_inline_data_nolock(inode);
+
+ kaddr = kmap_local_folio(folio, 0);
+ ext4_write_inline_data(inode, &iloc, kaddr, pos, copied);
+ kunmap_local(kaddr);
+ folio_mark_uptodate(folio);
+ /* clear dirty flag so that writepages wouldn't work for us. */
+ folio_clear_dirty(folio);
+
+ ext4_write_unlock_xattr(inode, &no_expand);
+ brelse(iloc.bh);
+
+ /*
+ * It's important to update i_size while still holding folio
+ * lock: page writeout could otherwise come in and zero
+ * beyond i_size.
+ */
+ ext4_update_inode_size(inode, pos + copied);
+ }
+ folio_unlock(folio);
+ folio_put(folio);
+
+ /*
+ * Don't mark the inode dirty under folio lock. First, it unnecessarily
+ * makes the holding time of folio lock longer. Second, it forces lock
+ * ordering of folio lock and transaction start for journaling
+ * filesystems.
+ */
+ if (likely(copied))
+ mark_inode_dirty(inode);
+out:
+ /*
+ * If we didn't copy as much data as expected, we need to trim back
+ * size of xattr containing inline data.
+ */
+ if (pos + len > inode->i_size && ext4_can_truncate(inode))
+ ext4_orphan_add(handle, inode);
+
+ ret2 = ext4_journal_stop(handle);
+ if (!ret)
+ ret = ret2;
+ if (pos + len > inode->i_size) {
+ ext4_truncate_failed_write(inode);
+ /*
+ * If truncate failed early the inode might still be
+ * on the orphan list; we need to make sure the inode
+ * is removed from the orphan list in that case.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(NULL, inode);
+ }
+ return ret ? ret : copied;
+}
+
+/*
+ * Try to make the page cache and handle ready for the inline data case.
+ * We can call this function in 2 cases:
+ * 1. The inode is created and the first write exceeds inline size. We can
+ * clear the inode state safely.
+ * 2. The inode has inline data, then we need to read the data, make it
+ * update and dirty so that ext4_da_writepages can handle it. We don't
+ * need to start the journal since the file's metadata isn't changed now.
+ */
+static int ext4_da_convert_inline_data_to_extent(struct address_space *mapping,
+ struct inode *inode,
+ void **fsdata)
+{
+ int ret = 0, inline_size;
+ struct folio *folio;
+
+ folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN,
+ mapping_gfp_mask(mapping));
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode)) {
+ ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+ goto out;
+ }
+
+ inline_size = ext4_get_inline_size(inode);
+
+ if (!folio_test_uptodate(folio)) {
+ ret = ext4_read_inline_folio(inode, folio);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = ext4_block_write_begin(NULL, folio, 0, inline_size,
+ ext4_da_get_block_prep);
+ if (ret) {
+ up_read(&EXT4_I(inode)->xattr_sem);
+ folio_unlock(folio);
+ folio_put(folio);
+ ext4_truncate_failed_write(inode);
+ return ret;
+ }
+
+ clear_buffer_new(folio_buffers(folio));
+ folio_mark_dirty(folio);
+ folio_mark_uptodate(folio);
+ ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+ *fsdata = (void *)CONVERT_INLINE_DATA;
+
+out:
+ up_read(&EXT4_I(inode)->xattr_sem);
+ if (folio) {
+ folio_unlock(folio);
+ folio_put(folio);
+ }
+ return ret;
+}
+
+#ifdef INLINE_DIR_DEBUG
+void ext4_show_inline_dir(struct inode *dir, struct buffer_head *bh,
+ void *inline_start, int inline_size)
+{
+ int offset;
+ unsigned short de_len;
+ struct ext4_dir_entry_2 *de = inline_start;
+ void *dlimit = inline_start + inline_size;
+
+ trace_printk("inode %lu\n", dir->i_ino);
+ offset = 0;
+ while ((void *)de < dlimit) {
+ de_len = ext4_rec_len_from_disk(de->rec_len, inline_size);
+ trace_printk("de: off %u rlen %u name %.*s nlen %u ino %u\n",
+ offset, de_len, de->name_len, de->name,
+ de->name_len, le32_to_cpu(de->inode));
+ if (ext4_check_dir_entry(dir, NULL, de, bh,
+ inline_start, inline_size, offset))
+ BUG();
+
+ offset += de_len;
+ de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
+ }
+}
+#else
+#define ext4_show_inline_dir(dir, bh, inline_start, inline_size)
+#endif
+
+/*
+ * Add a new entry into a inline dir.
+ * It will return -ENOSPC if no space is available, and -EIO
+ * and -EEXIST if directory entry already exists.
+ */
+static int ext4_add_dirent_to_inline(handle_t *handle,
+ struct ext4_filename *fname,
+ struct inode *dir,
+ struct inode *inode,
+ struct ext4_iloc *iloc,
+ void *inline_start, int inline_size)
+{
+ int err;
+ struct ext4_dir_entry_2 *de;
+
+ err = ext4_find_dest_de(dir, iloc->bh, inline_start,
+ inline_size, fname, &de);
+ if (err)
+ return err;
+
+ BUFFER_TRACE(iloc->bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, dir->i_sb, iloc->bh,
+ EXT4_JTR_NONE);
+ if (err)
+ return err;
+ ext4_insert_dentry(dir, inode, de, inline_size, fname);
+
+ ext4_show_inline_dir(dir, iloc->bh, inline_start, inline_size);
+
+ /*
+ * XXX shouldn't update any times until successful
+ * completion of syscall, but too many callers depend
+ * on this.
+ *
+ * XXX similarly, too many callers depend on
+ * ext4_new_inode() setting the times, but error
+ * recovery deletes the inode, so the worst that can
+ * happen is that the times are slightly out of date
+ * and/or different from the directory change time.
+ */
+ inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+ ext4_update_dx_flag(dir);
+ inode_inc_iversion(dir);
+ return 1;
+}
+
+static void *ext4_get_inline_xattr_pos(struct inode *inode,
+ struct ext4_iloc *iloc)
+{
+ struct ext4_xattr_entry *entry;
+ struct ext4_xattr_ibody_header *header;
+
+ BUG_ON(!EXT4_I(inode)->i_inline_off);
+
+ header = IHDR(inode, ext4_raw_inode(iloc));
+ entry = (struct ext4_xattr_entry *)((void *)ext4_raw_inode(iloc) +
+ EXT4_I(inode)->i_inline_off);
+
+ return (void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs);
+}
+
+/* Set the final de to cover the whole block. */
+void ext4_update_final_de(void *de_buf, int old_size, int new_size)
+{
+ struct ext4_dir_entry_2 *de, *prev_de;
+ void *limit;
+ int de_len;
+
+ de = de_buf;
+ if (old_size) {
+ limit = de_buf + old_size;
+ do {
+ prev_de = de;
+ de_len = ext4_rec_len_from_disk(de->rec_len, old_size);
+ de_buf += de_len;
+ de = de_buf;
+ } while (de_buf < limit);
+
+ prev_de->rec_len = ext4_rec_len_to_disk(de_len + new_size -
+ old_size, new_size);
+ } else {
+ /* this is just created, so create an empty entry. */
+ de->inode = 0;
+ de->rec_len = ext4_rec_len_to_disk(new_size, new_size);
+ }
+}
+
+static int ext4_update_inline_dir(handle_t *handle, struct inode *dir,
+ struct ext4_iloc *iloc)
+{
+ int ret;
+ int old_size = EXT4_I(dir)->i_inline_size - EXT4_MIN_INLINE_DATA_SIZE;
+ int new_size = get_max_inline_xattr_value_size(dir, iloc);
+
+ if (new_size - old_size <= ext4_dir_rec_len(1, NULL))
+ return -ENOSPC;
+
+ ret = ext4_update_inline_data(handle, dir,
+ new_size + EXT4_MIN_INLINE_DATA_SIZE);
+ if (ret)
+ return ret;
+
+ ext4_update_final_de(ext4_get_inline_xattr_pos(dir, iloc), old_size,
+ EXT4_I(dir)->i_inline_size -
+ EXT4_MIN_INLINE_DATA_SIZE);
+ dir->i_size = EXT4_I(dir)->i_disksize = EXT4_I(dir)->i_inline_size;
+ return 0;
+}
+
+static void ext4_restore_inline_data(handle_t *handle, struct inode *inode,
+ struct ext4_iloc *iloc,
+ void *buf, int inline_size)
+{
+ int ret;
+
+ ret = ext4_create_inline_data(handle, inode, inline_size);
+ if (ret) {
+ ext4_msg(inode->i_sb, KERN_EMERG,
+ "error restoring inline_data for inode -- potential data loss! (inode %lu, error %d)",
+ inode->i_ino, ret);
+ return;
+ }
+ ext4_write_inline_data(inode, iloc, buf, 0, inline_size);
+ ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+}
+
+static int ext4_convert_inline_data_nolock(handle_t *handle,
+ struct inode *inode,
+ struct ext4_iloc *iloc)
+{
+ int error;
+ void *buf = NULL;
+ struct buffer_head *data_bh = NULL;
+ struct ext4_map_blocks map;
+ int inline_size;
+
+ inline_size = ext4_get_inline_size(inode);
+ buf = kmalloc(inline_size, GFP_NOFS);
+ if (!buf) {
+ error = -ENOMEM;
+ goto out;
+ }
+
+ error = ext4_read_inline_data(inode, buf, inline_size, iloc);
+ if (error < 0)
+ goto out;
+
+ /*
+ * Make sure the inline directory entries pass checks before we try to
+ * convert them, so that we avoid touching stuff that needs fsck.
+ */
+ if (S_ISDIR(inode->i_mode)) {
+ error = ext4_check_all_de(inode, iloc->bh,
+ buf + EXT4_INLINE_DOTDOT_SIZE,
+ inline_size - EXT4_INLINE_DOTDOT_SIZE);
+ if (error)
+ goto out;
+ }
+
+ error = ext4_destroy_inline_data_nolock(handle, inode);
+ if (error)
+ goto out;
+
+ map.m_lblk = 0;
+ map.m_len = 1;
+ map.m_flags = 0;
+ error = ext4_map_blocks(handle, inode, &map, EXT4_GET_BLOCKS_CREATE);
+ if (error < 0)
+ goto out_restore;
+ if (!(map.m_flags & EXT4_MAP_MAPPED)) {
+ error = -EIO;
+ goto out_restore;
+ }
+
+ data_bh = sb_getblk(inode->i_sb, map.m_pblk);
+ if (!data_bh) {
+ error = -ENOMEM;
+ goto out_restore;
+ }
+
+ lock_buffer(data_bh);
+ error = ext4_journal_get_create_access(handle, inode->i_sb, data_bh,
+ EXT4_JTR_NONE);
+ if (error) {
+ unlock_buffer(data_bh);
+ error = -EIO;
+ goto out_restore;
+ }
+ memset(data_bh->b_data, 0, inode->i_sb->s_blocksize);
+
+ if (!S_ISDIR(inode->i_mode)) {
+ memcpy(data_bh->b_data, buf, inline_size);
+ set_buffer_uptodate(data_bh);
+ unlock_buffer(data_bh);
+ error = ext4_handle_dirty_metadata(handle,
+ inode, data_bh);
+ } else {
+ unlock_buffer(data_bh);
+ inode->i_size = inode->i_sb->s_blocksize;
+ i_size_write(inode, inode->i_sb->s_blocksize);
+ EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
+
+ error = ext4_init_dirblock(handle, inode, data_bh,
+ le32_to_cpu(((struct ext4_dir_entry_2 *)buf)->inode),
+ buf + EXT4_INLINE_DOTDOT_SIZE,
+ inline_size - EXT4_INLINE_DOTDOT_SIZE);
+ if (!error)
+ error = ext4_mark_inode_dirty(handle, inode);
+ }
+
+out_restore:
+ if (error)
+ ext4_restore_inline_data(handle, inode, iloc, buf, inline_size);
+
+out:
+ brelse(data_bh);
+ kfree(buf);
+ return error;
+}
+
+/*
+ * Try to add the new entry to the inline data.
+ * If succeeds, return 0. If not, extended the inline dir and copied data to
+ * the new created block.
+ */
+int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
+ struct inode *dir, struct inode *inode)
+{
+ int ret, ret2, inline_size, no_expand;
+ void *inline_start;
+ struct ext4_iloc iloc;
+
+ ret = ext4_get_inode_loc(dir, &iloc);
+ if (ret)
+ return ret;
+
+ ext4_write_lock_xattr(dir, &no_expand);
+ if (!ext4_has_inline_data(dir))
+ goto out;
+
+ inline_start = (void *)ext4_raw_inode(&iloc)->i_block +
+ EXT4_INLINE_DOTDOT_SIZE;
+ inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DOTDOT_SIZE;
+
+ ret = ext4_add_dirent_to_inline(handle, fname, dir, inode, &iloc,
+ inline_start, inline_size);
+ if (ret != -ENOSPC)
+ goto out;
+
+ /* check whether it can be inserted to inline xattr space. */
+ inline_size = EXT4_I(dir)->i_inline_size -
+ EXT4_MIN_INLINE_DATA_SIZE;
+ if (!inline_size) {
+ /* Try to use the xattr space.*/
+ ret = ext4_update_inline_dir(handle, dir, &iloc);
+ if (ret && ret != -ENOSPC)
+ goto out;
+
+ inline_size = EXT4_I(dir)->i_inline_size -
+ EXT4_MIN_INLINE_DATA_SIZE;
+ }
+
+ if (inline_size) {
+ inline_start = ext4_get_inline_xattr_pos(dir, &iloc);
+
+ ret = ext4_add_dirent_to_inline(handle, fname, dir,
+ inode, &iloc, inline_start,
+ inline_size);
+
+ if (ret != -ENOSPC)
+ goto out;
+ }
+
+ /*
+ * The inline space is filled up, so create a new block for it.
+ * As the extent tree will be created, we have to save the inline
+ * dir first.
+ */
+ ret = ext4_convert_inline_data_nolock(handle, dir, &iloc);
+
+out:
+ ext4_write_unlock_xattr(dir, &no_expand);
+ ret2 = ext4_mark_inode_dirty(handle, dir);
+ if (unlikely(ret2 && !ret))
+ ret = ret2;
+ brelse(iloc.bh);
+ return ret;
+}
+
+/*
+ * This function fills a red-black tree with information from an
+ * inlined dir. It returns the number directory entries loaded
+ * into the tree. If there is an error it is returned in err.
+ */
+int ext4_inlinedir_to_tree(struct file *dir_file,
+ struct inode *dir, ext4_lblk_t block,
+ struct dx_hash_info *hinfo,
+ __u32 start_hash, __u32 start_minor_hash,
+ int *has_inline_data)
+{
+ int err = 0, count = 0;
+ unsigned int parent_ino;
+ int pos;
+ struct ext4_dir_entry_2 *de;
+ struct inode *inode = file_inode(dir_file);
+ int ret, inline_size = 0;
+ struct ext4_iloc iloc;
+ void *dir_buf = NULL;
+ struct ext4_dir_entry_2 fake;
+ struct fscrypt_str tmp_str;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode)) {
+ up_read(&EXT4_I(inode)->xattr_sem);
+ *has_inline_data = 0;
+ goto out;
+ }
+
+ inline_size = ext4_get_inline_size(inode);
+ dir_buf = kmalloc(inline_size, GFP_NOFS);
+ if (!dir_buf) {
+ ret = -ENOMEM;
+ up_read(&EXT4_I(inode)->xattr_sem);
+ goto out;
+ }
+
+ ret = ext4_read_inline_data(inode, dir_buf, inline_size, &iloc);
+ up_read(&EXT4_I(inode)->xattr_sem);
+ if (ret < 0)
+ goto out;
+
+ pos = 0;
+ parent_ino = le32_to_cpu(((struct ext4_dir_entry_2 *)dir_buf)->inode);
+ while (pos < inline_size) {
+ /*
+ * As inlined dir doesn't store any information about '.' and
+ * only the inode number of '..' is stored, we have to handle
+ * them differently.
+ */
+ if (pos == 0) {
+ fake.inode = cpu_to_le32(inode->i_ino);
+ fake.name_len = 1;
+ memcpy(fake.name, ".", 2);
+ fake.rec_len = ext4_rec_len_to_disk(
+ ext4_dir_rec_len(fake.name_len, NULL),
+ inline_size);
+ ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
+ de = &fake;
+ pos = EXT4_INLINE_DOTDOT_OFFSET;
+ } else if (pos == EXT4_INLINE_DOTDOT_OFFSET) {
+ fake.inode = cpu_to_le32(parent_ino);
+ fake.name_len = 2;
+ memcpy(fake.name, "..", 3);
+ fake.rec_len = ext4_rec_len_to_disk(
+ ext4_dir_rec_len(fake.name_len, NULL),
+ inline_size);
+ ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
+ de = &fake;
+ pos = EXT4_INLINE_DOTDOT_SIZE;
+ } else {
+ de = (struct ext4_dir_entry_2 *)(dir_buf + pos);
+ pos += ext4_rec_len_from_disk(de->rec_len, inline_size);
+ if (ext4_check_dir_entry(inode, dir_file, de,
+ iloc.bh, dir_buf,
+ inline_size, pos)) {
+ ret = count;
+ goto out;
+ }
+ }
+
+ if (ext4_hash_in_dirent(dir)) {
+ hinfo->hash = EXT4_DIRENT_HASH(de);
+ hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de);
+ } else {
+ err = ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
+ if (err) {
+ ret = err;
+ goto out;
+ }
+ }
+ if ((hinfo->hash < start_hash) ||
+ ((hinfo->hash == start_hash) &&
+ (hinfo->minor_hash < start_minor_hash)))
+ continue;
+ if (de->inode == 0)
+ continue;
+ tmp_str.name = de->name;
+ tmp_str.len = de->name_len;
+ err = ext4_htree_store_dirent(dir_file, hinfo->hash,
+ hinfo->minor_hash, de, &tmp_str);
+ if (err) {
+ ret = err;
+ goto out;
+ }
+ count++;
+ }
+ ret = count;
+out:
+ kfree(dir_buf);
+ brelse(iloc.bh);
+ return ret;
+}
+
+/*
+ * So this function is called when the volume is mkfsed with
+ * dir_index disabled. In order to keep f_pos persistent
+ * after we convert from an inlined dir to a blocked based,
+ * we just pretend that we are a normal dir and return the
+ * offset as if '.' and '..' really take place.
+ *
+ */
+int ext4_read_inline_dir(struct file *file,
+ struct dir_context *ctx,
+ int *has_inline_data)
+{
+ unsigned int offset, parent_ino;
+ int i;
+ struct ext4_dir_entry_2 *de;
+ struct super_block *sb;
+ struct inode *inode = file_inode(file);
+ int ret, inline_size = 0;
+ struct ext4_iloc iloc;
+ void *dir_buf = NULL;
+ int dotdot_offset, dotdot_size, extra_offset, extra_size;
+ struct dir_private_info *info = file->private_data;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode)) {
+ up_read(&EXT4_I(inode)->xattr_sem);
+ *has_inline_data = 0;
+ goto out;
+ }
+
+ inline_size = ext4_get_inline_size(inode);
+ dir_buf = kmalloc(inline_size, GFP_NOFS);
+ if (!dir_buf) {
+ ret = -ENOMEM;
+ up_read(&EXT4_I(inode)->xattr_sem);
+ goto out;
+ }
+
+ ret = ext4_read_inline_data(inode, dir_buf, inline_size, &iloc);
+ up_read(&EXT4_I(inode)->xattr_sem);
+ if (ret < 0)
+ goto out;
+
+ ret = 0;
+ sb = inode->i_sb;
+ parent_ino = le32_to_cpu(((struct ext4_dir_entry_2 *)dir_buf)->inode);
+ offset = ctx->pos;
+
+ /*
+ * dotdot_offset and dotdot_size is the real offset and
+ * size for ".." and "." if the dir is block based while
+ * the real size for them are only EXT4_INLINE_DOTDOT_SIZE.
+ * So we will use extra_offset and extra_size to indicate them
+ * during the inline dir iteration.
+ */
+ dotdot_offset = ext4_dir_rec_len(1, NULL);
+ dotdot_size = dotdot_offset + ext4_dir_rec_len(2, NULL);
+ extra_offset = dotdot_size - EXT4_INLINE_DOTDOT_SIZE;
+ extra_size = extra_offset + inline_size;
+
+ /*
+ * If the cookie has changed since the last call to
+ * readdir(2), then we might be pointing to an invalid
+ * dirent right now. Scan from the start of the inline
+ * dir to make sure.
+ */
+ if (!inode_eq_iversion(inode, info->cookie)) {
+ for (i = 0; i < extra_size && i < offset;) {
+ /*
+ * "." is with offset 0 and
+ * ".." is dotdot_offset.
+ */
+ if (!i) {
+ i = dotdot_offset;
+ continue;
+ } else if (i == dotdot_offset) {
+ i = dotdot_size;
+ continue;
+ }
+ /* for other entry, the real offset in
+ * the buf has to be tuned accordingly.
+ */
+ de = (struct ext4_dir_entry_2 *)
+ (dir_buf + i - extra_offset);
+ /* It's too expensive to do a full
+ * dirent test each time round this
+ * loop, but we do have to test at
+ * least that it is non-zero. A
+ * failure will be detected in the
+ * dirent test below. */
+ if (ext4_rec_len_from_disk(de->rec_len, extra_size)
+ < ext4_dir_rec_len(1, NULL))
+ break;
+ i += ext4_rec_len_from_disk(de->rec_len,
+ extra_size);
+ }
+ offset = i;
+ ctx->pos = offset;
+ info->cookie = inode_query_iversion(inode);
+ }
+
+ while (ctx->pos < extra_size) {
+ if (ctx->pos == 0) {
+ if (!dir_emit(ctx, ".", 1, inode->i_ino, DT_DIR))
+ goto out;
+ ctx->pos = dotdot_offset;
+ continue;
+ }
+
+ if (ctx->pos == dotdot_offset) {
+ if (!dir_emit(ctx, "..", 2, parent_ino, DT_DIR))
+ goto out;
+ ctx->pos = dotdot_size;
+ continue;
+ }
+
+ de = (struct ext4_dir_entry_2 *)
+ (dir_buf + ctx->pos - extra_offset);
+ if (ext4_check_dir_entry(inode, file, de, iloc.bh, dir_buf,
+ extra_size, ctx->pos))
+ goto out;
+ if (le32_to_cpu(de->inode)) {
+ if (!dir_emit(ctx, de->name, de->name_len,
+ le32_to_cpu(de->inode),
+ get_dtype(sb, de->file_type)))
+ goto out;
+ }
+ ctx->pos += ext4_rec_len_from_disk(de->rec_len, extra_size);
+ }
+out:
+ kfree(dir_buf);
+ brelse(iloc.bh);
+ return ret;
+}
+
+void *ext4_read_inline_link(struct inode *inode)
+{
+ struct ext4_iloc iloc;
+ int ret, inline_size;
+ void *link;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ERR_PTR(ret);
+
+ ret = -ENOMEM;
+ inline_size = ext4_get_inline_size(inode);
+ link = kmalloc(inline_size + 1, GFP_NOFS);
+ if (!link)
+ goto out;
+
+ ret = ext4_read_inline_data(inode, link, inline_size, &iloc);
+ if (ret < 0) {
+ kfree(link);
+ goto out;
+ }
+ nd_terminate_link(link, inode->i_size, ret);
+out:
+ if (ret < 0)
+ link = ERR_PTR(ret);
+ brelse(iloc.bh);
+ return link;
+}
+
+struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
+ struct ext4_dir_entry_2 **parent_de,
+ int *retval)
+{
+ struct ext4_iloc iloc;
+
+ *retval = ext4_get_inode_loc(inode, &iloc);
+ if (*retval)
+ return NULL;
+
+ *parent_de = (struct ext4_dir_entry_2 *)ext4_raw_inode(&iloc)->i_block;
+
+ return iloc.bh;
+}
+
+/*
+ * Try to create the inline data for the new dir.
+ * If it succeeds, return 0, otherwise return the error.
+ * In case of ENOSPC, the caller should create the normal disk layout dir.
+ */
+int ext4_try_create_inline_dir(handle_t *handle, struct inode *parent,
+ struct inode *inode)
+{
+ int ret, inline_size = EXT4_MIN_INLINE_DATA_SIZE;
+ struct ext4_iloc iloc;
+ struct ext4_dir_entry_2 *de;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+ ret = ext4_prepare_inline_data(handle, inode, inline_size);
+ if (ret)
+ goto out;
+
+ /*
+ * For inline dir, we only save the inode information for the ".."
+ * and create a fake dentry to cover the left space.
+ */
+ de = (struct ext4_dir_entry_2 *)ext4_raw_inode(&iloc)->i_block;
+ de->inode = cpu_to_le32(parent->i_ino);
+ de = (struct ext4_dir_entry_2 *)((void *)de + EXT4_INLINE_DOTDOT_SIZE);
+ de->inode = 0;
+ de->rec_len = ext4_rec_len_to_disk(
+ inline_size - EXT4_INLINE_DOTDOT_SIZE,
+ inline_size);
+ set_nlink(inode, 2);
+ inode->i_size = EXT4_I(inode)->i_disksize = inline_size;
+out:
+ brelse(iloc.bh);
+ return ret;
+}
+
+struct buffer_head *ext4_find_inline_entry(struct inode *dir,
+ struct ext4_filename *fname,
+ struct ext4_dir_entry_2 **res_dir,
+ int *has_inline_data)
+{
+ struct ext4_xattr_ibody_find is = {
+ .s = { .not_found = -ENODATA, },
+ };
+ struct ext4_xattr_info i = {
+ .name_index = EXT4_XATTR_INDEX_SYSTEM,
+ .name = EXT4_XATTR_SYSTEM_DATA,
+ };
+ int ret;
+ void *inline_start;
+ int inline_size;
+
+ ret = ext4_get_inode_loc(dir, &is.iloc);
+ if (ret)
+ return ERR_PTR(ret);
+
+ down_read(&EXT4_I(dir)->xattr_sem);
+
+ ret = ext4_xattr_ibody_find(dir, &i, &is);
+ if (ret)
+ goto out;
+
+ if (!ext4_has_inline_data(dir)) {
+ *has_inline_data = 0;
+ goto out;
+ }
+
+ inline_start = (void *)ext4_raw_inode(&is.iloc)->i_block +
+ EXT4_INLINE_DOTDOT_SIZE;
+ inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DOTDOT_SIZE;
+ ret = ext4_search_dir(is.iloc.bh, inline_start, inline_size,
+ dir, fname, 0, res_dir);
+ if (ret == 1)
+ goto out_find;
+ if (ret < 0)
+ goto out;
+
+ if (ext4_get_inline_size(dir) == EXT4_MIN_INLINE_DATA_SIZE)
+ goto out;
+
+ inline_start = ext4_get_inline_xattr_pos(dir, &is.iloc);
+ inline_size = ext4_get_inline_size(dir) - EXT4_MIN_INLINE_DATA_SIZE;
+
+ ret = ext4_search_dir(is.iloc.bh, inline_start, inline_size,
+ dir, fname, 0, res_dir);
+ if (ret == 1)
+ goto out_find;
+
+out:
+ brelse(is.iloc.bh);
+ if (ret < 0)
+ is.iloc.bh = ERR_PTR(ret);
+ else
+ is.iloc.bh = NULL;
+out_find:
+ up_read(&EXT4_I(dir)->xattr_sem);
+ return is.iloc.bh;
+}
+
+int ext4_delete_inline_entry(handle_t *handle,
+ struct inode *dir,
+ struct ext4_dir_entry_2 *de_del,
+ struct buffer_head *bh,
+ int *has_inline_data)
+{
+ int err, inline_size, no_expand;
+ struct ext4_iloc iloc;
+ void *inline_start;
+
+ err = ext4_get_inode_loc(dir, &iloc);
+ if (err)
+ return err;
+
+ ext4_write_lock_xattr(dir, &no_expand);
+ if (!ext4_has_inline_data(dir)) {
+ *has_inline_data = 0;
+ goto out;
+ }
+
+ if ((void *)de_del - ((void *)ext4_raw_inode(&iloc)->i_block) <
+ EXT4_MIN_INLINE_DATA_SIZE) {
+ inline_start = (void *)ext4_raw_inode(&iloc)->i_block +
+ EXT4_INLINE_DOTDOT_SIZE;
+ inline_size = EXT4_MIN_INLINE_DATA_SIZE -
+ EXT4_INLINE_DOTDOT_SIZE;
+ } else {
+ inline_start = ext4_get_inline_xattr_pos(dir, &iloc);
+ inline_size = ext4_get_inline_size(dir) -
+ EXT4_MIN_INLINE_DATA_SIZE;
+ }
+
+ BUFFER_TRACE(bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (err)
+ goto out;
+
+ err = ext4_generic_delete_entry(dir, de_del, bh,
+ inline_start, inline_size, 0);
+ if (err)
+ goto out;
+
+ ext4_show_inline_dir(dir, iloc.bh, inline_start, inline_size);
+out:
+ ext4_write_unlock_xattr(dir, &no_expand);
+ if (likely(err == 0))
+ err = ext4_mark_inode_dirty(handle, dir);
+ brelse(iloc.bh);
+ if (err != -ENOENT)
+ ext4_std_error(dir->i_sb, err);
+ return err;
+}
+
+/*
+ * Get the inline dentry at offset.
+ */
+static inline struct ext4_dir_entry_2 *
+ext4_get_inline_entry(struct inode *inode,
+ struct ext4_iloc *iloc,
+ unsigned int offset,
+ void **inline_start,
+ int *inline_size)
+{
+ void *inline_pos;
+
+ BUG_ON(offset > ext4_get_inline_size(inode));
+
+ if (offset < EXT4_MIN_INLINE_DATA_SIZE) {
+ inline_pos = (void *)ext4_raw_inode(iloc)->i_block;
+ *inline_size = EXT4_MIN_INLINE_DATA_SIZE;
+ } else {
+ inline_pos = ext4_get_inline_xattr_pos(inode, iloc);
+ offset -= EXT4_MIN_INLINE_DATA_SIZE;
+ *inline_size = ext4_get_inline_size(inode) -
+ EXT4_MIN_INLINE_DATA_SIZE;
+ }
+
+ if (inline_start)
+ *inline_start = inline_pos;
+ return (struct ext4_dir_entry_2 *)(inline_pos + offset);
+}
+
+bool empty_inline_dir(struct inode *dir, int *has_inline_data)
+{
+ int err, inline_size;
+ struct ext4_iloc iloc;
+ size_t inline_len;
+ void *inline_pos;
+ unsigned int offset;
+ struct ext4_dir_entry_2 *de;
+ bool ret = false;
+
+ err = ext4_get_inode_loc(dir, &iloc);
+ if (err) {
+ EXT4_ERROR_INODE_ERR(dir, -err,
+ "error %d getting inode %lu block",
+ err, dir->i_ino);
+ return false;
+ }
+
+ down_read(&EXT4_I(dir)->xattr_sem);
+ if (!ext4_has_inline_data(dir)) {
+ *has_inline_data = 0;
+ ret = true;
+ goto out;
+ }
+
+ de = (struct ext4_dir_entry_2 *)ext4_raw_inode(&iloc)->i_block;
+ if (!le32_to_cpu(de->inode)) {
+ ext4_warning(dir->i_sb,
+ "bad inline directory (dir #%lu) - no `..'",
+ dir->i_ino);
+ goto out;
+ }
+
+ inline_len = ext4_get_inline_size(dir);
+ offset = EXT4_INLINE_DOTDOT_SIZE;
+ while (offset < inline_len) {
+ de = ext4_get_inline_entry(dir, &iloc, offset,
+ &inline_pos, &inline_size);
+ if (ext4_check_dir_entry(dir, NULL, de,
+ iloc.bh, inline_pos,
+ inline_size, offset)) {
+ ext4_warning(dir->i_sb,
+ "bad inline directory (dir #%lu) - "
+ "inode %u, rec_len %u, name_len %d"
+ "inline size %d",
+ dir->i_ino, le32_to_cpu(de->inode),
+ le16_to_cpu(de->rec_len), de->name_len,
+ inline_size);
+ goto out;
+ }
+ if (le32_to_cpu(de->inode)) {
+ goto out;
+ }
+ offset += ext4_rec_len_from_disk(de->rec_len, inline_size);
+ }
+
+ ret = true;
+out:
+ up_read(&EXT4_I(dir)->xattr_sem);
+ brelse(iloc.bh);
+ return ret;
+}
+
+int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
+{
+ int ret, no_expand;
+
+ ext4_write_lock_xattr(inode, &no_expand);
+ ret = ext4_destroy_inline_data_nolock(handle, inode);
+ ext4_write_unlock_xattr(inode, &no_expand);
+
+ return ret;
+}
+
+int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap)
+{
+ __u64 addr;
+ int error = -EAGAIN;
+ struct ext4_iloc iloc;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode))
+ goto out;
+
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error)
+ goto out;
+
+ addr = (__u64)iloc.bh->b_blocknr << inode->i_sb->s_blocksize_bits;
+ addr += (char *)ext4_raw_inode(&iloc) - iloc.bh->b_data;
+ addr += offsetof(struct ext4_inode, i_block);
+
+ brelse(iloc.bh);
+
+ iomap->addr = addr;
+ iomap->offset = 0;
+ iomap->length = min_t(loff_t, ext4_get_inline_size(inode),
+ i_size_read(inode));
+ iomap->type = IOMAP_INLINE;
+ iomap->flags = 0;
+
+out:
+ up_read(&EXT4_I(inode)->xattr_sem);
+ return error;
+}
+
+int ext4_inline_data_truncate(struct inode *inode, int *has_inline)
+{
+ handle_t *handle;
+ int inline_size, value_len, needed_blocks, no_expand, err = 0;
+ size_t i_size;
+ void *value = NULL;
+ struct ext4_xattr_ibody_find is = {
+ .s = { .not_found = -ENODATA, },
+ };
+ struct ext4_xattr_info i = {
+ .name_index = EXT4_XATTR_INDEX_SYSTEM,
+ .name = EXT4_XATTR_SYSTEM_DATA,
+ };
+
+
+ needed_blocks = ext4_chunk_trans_extent(inode, 1);
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, needed_blocks);
+ if (IS_ERR(handle))
+ return PTR_ERR(handle);
+
+ ext4_write_lock_xattr(inode, &no_expand);
+ if (!ext4_has_inline_data(inode)) {
+ ext4_write_unlock_xattr(inode, &no_expand);
+ *has_inline = 0;
+ ext4_journal_stop(handle);
+ return 0;
+ }
+
+ if ((err = ext4_orphan_add(handle, inode)) != 0)
+ goto out;
+
+ if ((err = ext4_get_inode_loc(inode, &is.iloc)) != 0)
+ goto out;
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+ i_size = inode->i_size;
+ inline_size = ext4_get_inline_size(inode);
+ EXT4_I(inode)->i_disksize = i_size;
+
+ if (i_size < inline_size) {
+ /*
+ * if there's inline data to truncate and this file was
+ * converted to extents after that inline data was written,
+ * the extent status cache must be cleared to avoid leaving
+ * behind stale delayed allocated extent entries
+ */
+ if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
+ ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
+
+ /* Clear the content in the xattr space. */
+ if (inline_size > EXT4_MIN_INLINE_DATA_SIZE) {
+ if ((err = ext4_xattr_ibody_find(inode, &i, &is)) != 0)
+ goto out_error;
+
+ if (is.s.not_found) {
+ EXT4_ERROR_INODE(inode,
+ "missing inline data xattr");
+ err = -EFSCORRUPTED;
+ goto out_error;
+ }
+
+ value_len = le32_to_cpu(is.s.here->e_value_size);
+ value = kmalloc(value_len, GFP_NOFS);
+ if (!value) {
+ err = -ENOMEM;
+ goto out_error;
+ }
+
+ err = ext4_xattr_ibody_get(inode, i.name_index,
+ i.name, value, value_len);
+ if (err <= 0)
+ goto out_error;
+
+ i.value = value;
+ i.value_len = i_size > EXT4_MIN_INLINE_DATA_SIZE ?
+ i_size - EXT4_MIN_INLINE_DATA_SIZE : 0;
+ err = ext4_xattr_ibody_set(handle, inode, &i, &is);
+ if (err)
+ goto out_error;
+ }
+
+ /* Clear the content within i_blocks. */
+ if (i_size < EXT4_MIN_INLINE_DATA_SIZE) {
+ void *p = (void *) ext4_raw_inode(&is.iloc)->i_block;
+ memset(p + i_size, 0,
+ EXT4_MIN_INLINE_DATA_SIZE - i_size);
+ }
+
+ EXT4_I(inode)->i_inline_size = i_size <
+ EXT4_MIN_INLINE_DATA_SIZE ?
+ EXT4_MIN_INLINE_DATA_SIZE : i_size;
+ }
+
+out_error:
+ up_write(&EXT4_I(inode)->i_data_sem);
+out:
+ brelse(is.iloc.bh);
+ ext4_write_unlock_xattr(inode, &no_expand);
+ kfree(value);
+ if (inode->i_nlink)
+ ext4_orphan_del(handle, inode);
+
+ if (err == 0) {
+ inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+ err = ext4_mark_inode_dirty(handle, inode);
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+ }
+ ext4_journal_stop(handle);
+ return err;
+}
+
+int ext4_convert_inline_data(struct inode *inode)
+{
+ int error, needed_blocks, no_expand;
+ handle_t *handle;
+ struct ext4_iloc iloc;
+
+ if (!ext4_has_inline_data(inode)) {
+ ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
+ return 0;
+ } else if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
+ /*
+ * Inode has inline data but EXT4_STATE_MAY_INLINE_DATA is
+ * cleared. This means we are in the middle of moving of
+ * inline data to delay allocated block. Just force writeout
+ * here to finish conversion.
+ */
+ error = filemap_flush(inode->i_mapping);
+ if (error)
+ return error;
+ if (!ext4_has_inline_data(inode))
+ return 0;
+ }
+
+ needed_blocks = ext4_chunk_trans_extent(inode, 1);
+
+ iloc.bh = NULL;
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error)
+ return error;
+
+ handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
+ if (IS_ERR(handle)) {
+ error = PTR_ERR(handle);
+ goto out_free;
+ }
+
+ ext4_write_lock_xattr(inode, &no_expand);
+ if (ext4_has_inline_data(inode))
+ error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
+ ext4_write_unlock_xattr(inode, &no_expand);
+ ext4_journal_stop(handle);
+out_free:
+ brelse(iloc.bh);
+ return error;
+}