litmus-rt.git - The LITMUS^RT kernel.

The LITMUS^RT kernel.

Bjoern Brandenburg

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	Commit message (Expand)	Author	Age
*	Linux-2.6.12-rc2v2.6.12-rc2	Linus Torvalds	2005-04-16

/* * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com * Written by Alex Tomas <alex@clusterfs.com> * * Architecture independence: * Copyright (c) 2005, Bull S.A. * Written by Pierre Peiffer <pierre.peiffer@bull.net> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public Licens * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- */ /* * Extents support for EXT4 * * TODO: * - ext4*_error() should be used in some situations * - analyze all BUG()/BUG_ON(), use -EIO where appropriate * - smart tree reduction */ #include <linux/module.h> #include <linux/fs.h> #include <linux/time.h> #include <linux/jbd2.h> #include <linux/highuid.h> #include <linux/pagemap.h> #include <linux/quotaops.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/falloc.h> #include <asm/uaccess.h> #include <linux/fiemap.h> #include "ext4_jbd2.h" #include "ext4_extents.h" #include <trace/events/ext4.h> static int ext4_split_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_map_blocks *map, int split_flag, int flags); static int ext4_ext_truncate_extend_restart(handle_t *handle, struct inode *inode, int needed) { int err; if (!ext4_handle_valid(handle)) return 0; if (handle->h_buffer_credits > needed) return 0; err = ext4_journal_extend(handle, needed); if (err <= 0) return err; err = ext4_truncate_restart_trans(handle, inode, needed); if (err == 0) err = -EAGAIN; return err; } /* * could return: * - EROFS * - ENOMEM */ static int ext4_ext_get_access(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { if (path->p_bh) { /* path points to block */ return ext4_journal_get_write_access(handle, path->p_bh); } /* path points to leaf/index in inode body */ /* we use in-core data, no need to protect them */ return 0; } /* * could return: * - EROFS * - ENOMEM * - EIO */ static int ext4_ext_dirty(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { int err; if (path->p_bh) { /* path points to block */ err = ext4_handle_dirty_metadata(handle, inode, path->p_bh); } else { /* path points to leaf/index in inode body */ err = ext4_mark_inode_dirty(handle, inode); } return err; } static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { int depth; if (path) { struct ext4_extent *ex; depth = path->p_depth; /* * Try to predict block placement assuming that we are * filling in a file which will eventually be * non-sparse --- i.e., in the case of libbfd writing * an ELF object sections out-of-order but in a way * the eventually results in a contiguous object or * executable file, or some database extending a table * space file. However, this is actually somewhat * non-ideal if we are writing a sparse file such as * qemu or KVM writing a raw image file that is going * to stay fairly sparse, since it will end up * fragmenting the file system's free space. Maybe we * should have some hueristics or some way to allow * userspace to pass a hint to file system, * especially if the latter case turns out to be * common. */ ex = path[depth].p_ext; if (ex) { ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); if (block > ext_block) return ext_pblk + (block - ext_block); else return ext_pblk - (ext_block - block); } /* it looks like index is empty; * try to find starting block from index itself */ if (path[depth].p_bh) return path[depth].p_bh->b_blocknr; } /* OK. use inode's group */ return ext4_inode_to_goal_block(inode); } /* * Allocation for a meta data block */ static ext4_fsblk_t ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex, int *err, unsigned int flags) { ext4_fsblk_t goal, newblock; goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); newblock = ext4_new_meta_blocks(handle, inode, goal, flags, NULL, err); return newblock; } static inline int ext4_ext_space_block(struct inode *inode, int check) { int size; size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) / sizeof(struct ext4_extent); if (!check) { #ifdef AGGRESSIVE_TEST if (size > 6) size = 6; #endif } return size; } static inline int ext4_ext_space_block_idx(struct inode *inode, int check) { int size; size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) / sizeof(struct ext4_extent_idx); if (!check) { #ifdef AGGRESSIVE_TEST if (size > 5) size = 5; #endif } return size; } static inline int ext4_ext_space_root(struct inode *inode, int check) { int size; size = sizeof(EXT4_I(inode)->i_data); size -= sizeof(struct ext4_extent_header); size /= sizeof(struct ext4_extent); if (!check) { #ifdef AGGRESSIVE_TEST if (size > 3) size = 3; #endif } return size; } static inline int ext4_ext_space_root_idx(struct inode *inode, int check) { int size; size = sizeof(EXT4_I(inode)->i_data); size -= sizeof(struct ext4_extent_header); size /= sizeof(struct ext4_extent_idx); if (!check) { #ifdef AGGRESSIVE_TEST if (size > 4) size = 4; #endif } return size; } /* * Calculate the number of metadata blocks needed * to allocate @blocks * Worse case is one block per extent */ int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) { struct ext4_inode_info *ei = EXT4_I(inode); int idxs, num = 0; idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) / sizeof(struct ext4_extent_idx)); /* * If the new delayed allocation block is contiguous with the * previous da block, it can share index blocks with the * previous block, so we only need to allocate a new index * block every idxs leaf blocks. At ldxs**2 blocks, we need * an additional index block, and at ldxs**3 blocks, yet * another index blocks. */ if (ei->i_da_metadata_calc_len && ei->i_da_metadata_calc_last_lblock+1 == lblock) { if ((ei->i_da_metadata_calc_len % idxs) == 0) num++; if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0) num++; if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) { num++; ei->i_da_metadata_calc_len = 0; } else ei->i_da_metadata_calc_len++; ei->i_da_metadata_calc_last_lblock++; return num; } /* * In the worst case we need a new set of index blocks at * every level of the inode's extent tree. */ ei->i_da_metadata_calc_len = 1; ei->i_da_metadata_calc_last_lblock = lblock; return ext_depth(inode) + 1; } static int ext4_ext_max_entries(struct inode *inode, int depth) { int max; if (depth == ext_depth(inode)) { if (depth == 0) max = ext4_ext_space_root(inode, 1); else max = ext4_ext_space_root_idx(inode, 1); } else { if (depth == 0) max = ext4_ext_space_block(inode, 1); else max = ext4_ext_space_block_idx(inode, 1); } return max; } static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) { ext4_fsblk_t block = ext4_ext_pblock(ext); int len = ext4_ext_get_actual_len(ext); return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); } static int ext4_valid_extent_idx(struct inode *inode, struct ext4_extent_idx *ext_idx) { ext4_fsblk_t block = ext4_idx_pblock(ext_idx); return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1); } static int ext4_valid_extent_entries(struct inode *inode, struct ext4_extent_header *eh, int depth) { struct ext4_extent *ext; struct ext4_extent_idx *ext_idx; unsigned short entries; if (eh->eh_entries == 0) return 1; entries = le16_to_cpu(eh->eh_entries); if (depth == 0) { /* leaf entries */ ext = EXT_FIRST_EXTENT(eh); while (entries) { if (!ext4_valid_extent(inode, ext)) return 0; ext++; entries--; } } else { ext_idx = EXT_FIRST_INDEX(eh); while (entries) { if (!ext4_valid_extent_idx(inode, ext_idx)) return 0; ext_idx++; entries--; } } return 1; } static int __ext4_ext_check(const char *function, unsigned int line, struct inode *inode, struct ext4_extent_header *eh, int depth) { const char *error_msg; int max = 0; if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { error_msg = "invalid magic"; goto corrupted; } if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { error_msg = "unexpected eh_depth"; goto corrupted; } if (unlikely(eh->eh_max == 0)) { error_msg = "invalid eh_max"; goto corrupted; } max = ext4_ext_max_entries(inode, depth); if (unlikely(le16_to_cpu(eh->eh_max) > max)) { error_msg = "too large eh_max"; goto corrupted; } if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { error_msg = "invalid eh_entries"; goto corrupted; } if (!ext4_valid_extent_entries(inode, eh, depth)) { error_msg = "invalid extent entries"; goto corrupted; } return 0; corrupted: ext4_error_inode(inode, function, line, 0, "bad header/extent: %s - magic %x, " "entries %u, max %u(%u), depth %u(%u)", error_msg, le16_to_cpu(eh->eh_magic), le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), max, le16_to_cpu(eh->eh_depth), depth); return -EIO; } #define ext4_ext_check(inode, eh, depth) \ __ext4_ext_check(__func__, __LINE__, inode, eh, depth) int ext4_ext_check_inode(struct inode *inode) { return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode)); } #ifdef EXT_DEBUG static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) { int k, l = path->p_depth; ext_debug("path:"); for (k = 0; k <= l; k++, path++) { if (path->p_idx) { ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), ext4_idx_pblock(path->p_idx)); } else if (path->p_ext) { ext_debug(" %d:[%d]%d:%llu ", le32_to_cpu(path->p_ext->ee_block), ext4_ext_is_uninitialized(path->p_ext), ext4_ext_get_actual_len(path->p_ext), ext4_ext_pblock(path->p_ext)); } else ext_debug(" []"); } ext_debug("\n"); } static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) { int depth = ext_depth(inode); struct ext4_extent_header *eh; struct ext4_extent *ex; int i; if (!path) return; eh = path[depth].p_hdr; ex = EXT_FIRST_EXTENT(eh); ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino); for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), ext4_ext_is_uninitialized(ex), ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); } ext_debug("\n"); } static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, ext4_fsblk_t newblock, int level) { int depth = ext_depth(inode); struct ext4_extent *ex; if (depth != level) { struct ext4_extent_idx *idx; idx = path[level].p_idx; while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { ext_debug("%d: move %d:%llu in new index %llu\n", level, le32_to_cpu(idx->ei_block), ext4_idx_pblock(idx), newblock); idx++; } return; } ex = path[depth].p_ext; while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n", le32_to_cpu(ex->ee_block), ext4_ext_pblock(ex), ext4_ext_is_uninitialized(ex), ext4_ext_get_actual_len(ex), newblock); ex++; } } #else #define ext4_ext_show_path(inode, path) #define ext4_ext_show_leaf(inode, path) #define ext4_ext_show_move(inode, path, newblock, level) #endif void ext4_ext_drop_refs(struct ext4_ext_path *path) { int depth = path->p_depth; int i; for (i = 0; i <= depth; i++, path++) if (path->p_bh) { brelse(path->p_bh); path->p_bh = NULL; } } /* * ext4_ext_binsearch_idx: * binary search for the closest index of the given block * the header must be checked before calling this */ static void ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { struct ext4_extent_header *eh = path->p_hdr; struct ext4_extent_idx *r, *l, *m; ext_debug("binsearch for %u(idx): ", block); l = EXT_FIRST_INDEX(eh) + 1; r = EXT_LAST_INDEX(eh); while (l <= r) { m = l + (r - l) / 2; if (block < le32_to_cpu(m->ei_block)) r = m - 1; else l = m + 1; ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block), r, le32_to_cpu(r->ei_block)); } path->p_idx = l - 1; ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), ext4_idx_pblock(path->p_idx)); #ifdef CHECK_BINSEARCH { struct ext4_extent_idx *chix, *ix; int k; chix = ix = EXT_FIRST_INDEX(eh); for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { if (k != 0 && le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { printk(KERN_DEBUG "k=%d, ix=0x%p, " "first=0x%p\n", k, ix, EXT_FIRST_INDEX(eh)); printk(KERN_DEBUG "%u <= %u\n", le32_to_cpu(ix->ei_block), le32_to_cpu(ix[-1].ei_block)); } BUG_ON(k && le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)); if (block < le32_to_cpu(ix->ei_block)) break; chix = ix; } BUG_ON(chix != path->p_idx); } #endif } /* * ext4_ext_binsearch: * binary search for closest extent of the given block * the header must be checked before calling this */ static void ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { struct ext4_extent_header *eh = path->p_hdr; struct ext4_extent *r, *l, *m; if (eh->eh_entries == 0) { /* * this leaf is empty: * we get such a leaf in split/add case */ return; } ext_debug("binsearch for %u: ", block); l = EXT_FIRST_EXTENT(eh) + 1; r = EXT_LAST_EXTENT(eh); while (l <= r) { m = l + (r - l) / 2; if (block < le32_to_cpu(m->ee_block)) r = m - 1; else l = m + 1; ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block), r, le32_to_cpu(r->ee_block)); } path->p_ext = l - 1; ext_debug(" -> %d:%llu:[%d]%d ", le32_to_cpu(path->p_ext->ee_block), ext4_ext_pblock(path->p_ext), ext4_ext_is_uninitialized(path->p_ext), ext4_ext_get_actual_len(path->p_ext)); #ifdef CHECK_BINSEARCH { struct ext4_extent *chex, *ex; int k; chex = ex = EXT_FIRST_EXTENT(eh); for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { BUG_ON(k && le32_to_cpu(ex->ee_block) <= le32_to_cpu(ex[-1].ee_block)); if (block < le32_to_cpu(ex->ee_block)) break; chex = ex; } BUG_ON(chex != path->p_ext); } #endif } int ext4_ext_tree_init(handle_t *handle, struct inode *inode) { struct ext4_extent_header *eh; eh = ext_inode_hdr(inode); eh->eh_depth = 0; eh->eh_entries = 0; eh->eh_magic = EXT4_EXT_MAGIC; eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); ext4_mark_inode_dirty(handle, inode); ext4_ext_invalidate_cache(inode); return 0; } struct ext4_ext_path * ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, struct ext4_ext_path *path) { struct ext4_extent_header *eh; struct buffer_head *bh; short int depth, i, ppos = 0, alloc = 0; eh = ext_inode_hdr(inode); depth = ext_depth(inode); /* account possible depth increase */ if (!path) { path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), GFP_NOFS); if (!path) return ERR_PTR(-ENOMEM); alloc = 1; } path[0].p_hdr = eh; path[0].p_bh = NULL; i = depth; /* walk through the tree */ while (i) { int need_to_validate = 0; ext_debug("depth %d: num %d, max %d\n", ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); ext4_ext_binsearch_idx(inode, path + ppos, block); path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); path[ppos].p_depth = i; path[ppos].p_ext = NULL; bh = sb_getblk(inode->i_sb, path[ppos].p_block); if (unlikely(!bh)) goto err; if (!bh_uptodate_or_lock(bh)) { trace_ext4_ext_load_extent(inode, block, path[ppos].p_block); if (bh_submit_read(bh) < 0) { put_bh(bh); goto err; } /* validate the extent entries */ need_to_validate = 1; } eh = ext_block_hdr(bh); ppos++; if (unlikely(ppos > depth)) { put_bh(bh); EXT4_ERROR_INODE(inode, "ppos %d > depth %d", ppos, depth); goto err; } path[ppos].p_bh = bh; path[ppos].p_hdr = eh; i--; if (need_to_validate && ext4_ext_check(inode, eh, i)) goto err; } path[ppos].p_depth = i; path[ppos].p_ext = NULL; path[ppos].p_idx = NULL; /* find extent */ ext4_ext_binsearch(inode, path + ppos, block); /* if not an empty leaf */ if (path[ppos].p_ext) path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); ext4_ext_show_path(inode, path); return path; err: ext4_ext_drop_refs(path); if (alloc) kfree(path); return ERR_PTR(-EIO); } /* * ext4_ext_insert_index: * insert new index [@logical;@ptr] into the block at @curp; * check where to insert: before @curp or after @curp */ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, struct ext4_ext_path *curp, int logical, ext4_fsblk_t ptr) { struct ext4_extent_idx *ix; int len, err; err = ext4_ext_get_access(handle, inode, curp); if (err) return err; if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { EXT4_ERROR_INODE(inode, "logical %d == ei_block %d!", logical, le32_to_cpu(curp->p_idx->ei_block)); return -EIO; } if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) >= le16_to_cpu(curp->p_hdr->eh_max))) { EXT4_ERROR_INODE(inode, "eh_entries %d >= eh_max %d!", le16_to_cpu(curp->p_hdr->eh_entries), le16_to_cpu(curp->p_hdr->eh_max)); return -EIO; } len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; if (logical > le32_to_cpu(curp->p_idx->ei_block)) { /* insert after */ if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { len = (len - 1) * sizeof(struct ext4_extent_idx); len = len < 0 ? 0 : len; ext_debug("insert new index %d after: %llu. " "move %d from 0x%p to 0x%p\n", logical, ptr, len, (curp->p_idx + 1), (curp->p_idx + 2)); memmove(curp->p_idx + 2, curp->p_idx + 1, len); } ix = curp->p_idx + 1; } else { /* insert before */ len = len * sizeof(struct ext4_extent_idx); len = len < 0 ? 0 : len; ext_debug("insert new index %d before: %llu. " "move %d from 0x%p to 0x%p\n", logical, ptr, len, curp->p_idx, (curp->p_idx + 1)); memmove(curp->p_idx + 1, curp->p_idx, len); ix = curp->p_idx; } ix->ei_block = cpu_to_le32(logical); ext4_idx_store_pblock(ix, ptr); le16_add_cpu(&curp->p_hdr->eh_entries, 1); if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); return -EIO; } err = ext4_ext_dirty(handle, inode, curp); ext4_std_error(inode->i_sb, err); return err; } /* * ext4_ext_split: * inserts new subtree into the path, using free index entry * at depth @at: * - allocates all needed blocks (new leaf and all intermediate index blocks) * - makes decision where to split * - moves remaining extents and index entries (right to the split point) * into the newly allocated blocks * - initializes subtree */ static int ext4_ext_split(handle_t *handle, struct inode *inode, unsigned int flags, struct ext4_ext_path *path, struct ext4_extent *newext, int at) { struct buffer_head *bh = NULL; int depth = ext_depth(inode); struct ext4_extent_header *neh; struct ext4_extent_idx *fidx; int i = at, k, m, a; ext4_fsblk_t newblock, oldblock; __le32 border; ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ int err = 0; /* make decision: where to split? */ /* FIXME: now decision is simplest: at current extent */ /* if current leaf will be split, then we should use * border from split point */ if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); return -EIO; } if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { border = path[depth].p_ext[1].ee_block; ext_debug("leaf will be split." " next leaf starts at %d\n", le32_to_cpu(border)); } else { border = newext->ee_block; ext_debug("leaf will be added." " next leaf starts at %d\n", le32_to_cpu(border)); } /* * If error occurs, then we break processing * and mark filesystem read-only. index won't * be inserted and tree will be in consistent * state. Next mount will repair buffers too. */ /* * Get array to track all allocated blocks. * We need this to handle errors and free blocks * upon them. */ ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); if (!ablocks) return -ENOMEM; /* allocate all needed blocks */ ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); for (a = 0; a < depth - at; a++) { newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err, flags); if (newblock == 0) goto cleanup; ablocks[a] = newblock; } /* initialize new leaf */ newblock = ablocks[--a]; if (unlikely(newblock == 0)) { EXT4_ERROR_INODE(inode, "newblock == 0!"); err = -EIO; goto cleanup; } bh = sb_getblk(inode->i_sb, newblock); if (!bh) { err = -EIO; goto cleanup; } lock_buffer(bh); err = ext4_journal_get_create_access(handle, bh); if (err) goto cleanup; neh = ext_block_hdr(bh); neh->eh_entries = 0; neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_depth = 0; /* move remainder of path[depth] to the new leaf */ if (unlikely(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max)) { EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", path[depth].p_hdr->eh_entries, path[depth].p_hdr->eh_max); err = -EIO; goto cleanup; } /* start copy from next extent */ m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++; ext4_ext_show_move(inode, path, newblock, depth); if (m) { struct ext4_extent *ex; ex = EXT_FIRST_EXTENT(neh); memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m); le16_add_cpu(&neh->eh_entries, m); } set_buffer_uptodate(bh); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, inode, bh); if (err) goto cleanup; brelse(bh); bh = NULL; /* correct old leaf */ if (m) { err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto cleanup; le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto cleanup; } /* create intermediate indexes */ k = depth - at - 1; if (unlikely(k < 0)) { EXT4_ERROR_INODE(inode, "k %d < 0!", k); err = -EIO; goto cleanup; } if (k) ext_debug("create %d intermediate indices\n", k); /* insert new index into current index block */ /* current depth stored in i var */ i = depth - 1; while (k--) { oldblock = newblock; newblock = ablocks[--a]; bh = sb_getblk(inode->i_sb, newblock); if (!bh) { err = -EIO; goto cleanup; } lock_buffer(bh); err = ext4_journal_get_create_access(handle, bh); if (err) goto cleanup; neh = ext_block_hdr(bh); neh->eh_entries = cpu_to_le16(1); neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); neh->eh_depth = cpu_to_le16(depth - i); fidx = EXT_FIRST_INDEX(neh); fidx->ei_block = border; ext4_idx_store_pblock(fidx, oldblock); ext_debug("int.index at %d (block %llu): %u -> %llu\n", i, newblock, le32_to_cpu(border), oldblock); /* move remainder of path[i] to the new index block */ if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != EXT_LAST_INDEX(path[i].p_hdr))) { EXT4_ERROR_INODE(inode, "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", le32_to_cpu(path[i].p_ext->ee_block)); err = -EIO; goto cleanup; } /* start copy indexes */ m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++; ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, EXT_MAX_INDEX(path[i].p_hdr)); ext4_ext_show_move(inode, path, newblock, i); if (m) { memmove(++fidx, path[i].p_idx, sizeof(struct ext4_extent_idx) * m); le16_add_cpu(&neh->eh_entries, m); } set_buffer_uptodate(bh); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, inode, bh); if (err) goto cleanup; brelse(bh); bh = NULL; /* correct old index */ if (m) { err = ext4_ext_get_access(handle, inode, path + i); if (err) goto cleanup; le16_add_cpu(&path[i].p_hdr->eh_entries, -m); err = ext4_ext_dirty(handle, inode, path + i); if (err) goto cleanup; } i--; } /* insert new index */ err = ext4_ext_insert_index(handle, inode, path + at, le32_to_cpu(border), newblock); cleanup: if (bh) { if (buffer_locked(bh)) unlock_buffer(bh); brelse(bh); } if (err) { /* free all allocated blocks in error case */ for (i = 0; i < depth; i++) { if (!ablocks[i]) continue; ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, EXT4_FREE_BLOCKS_METADATA); } } kfree(ablocks); return err; } /* * ext4_ext_grow_indepth: * implements tree growing procedure: * - allocates new block * - moves top-level data (index block or leaf) into the new block * - initializes new top-level, creating index that points to the * just created block */ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, unsigned int flags, struct ext4_ext_path *path, struct ext4_extent *newext) { struct ext4_ext_path *curp = path; struct ext4_extent_header *neh; struct buffer_head *bh; ext4_fsblk_t newblock; int err = 0; newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err, flags); if (newblock == 0) return err; bh = sb_getblk(inode->i_sb, newblock); if (!bh) { err = -EIO; ext4_std_error(inode->i_sb, err); return err; } lock_buffer(bh); err = ext4_journal_get_create_access(handle, bh); if (err) { unlock_buffer(bh); goto out; } /* move top-level index/leaf into new block */ memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); /* set size of new block */ neh = ext_block_hdr(bh); /* old root could have indexes or leaves * so calculate e_max right way */ if (ext_depth(inode)) neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); else neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); neh->eh_magic = EXT4_EXT_MAGIC; set_buffer_uptodate(bh); unlock_buffer(bh); err = ext4_handle_dirty_metadata(handle, inode, bh); if (err) goto out; /* create index in new top-level index: num,max,pointer */ err = ext4_ext_get_access(handle, inode, curp); if (err) goto out; curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); curp->p_hdr->eh_entries = cpu_to_le16(1); curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); if (path[0].p_hdr->eh_depth) curp->p_idx->ei_block = EXT_FIRST_INDEX(path[0].p_hdr)->ei_block; else curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; ext4_idx_store_pblock(curp->p_idx, newblock); neh = ext_inode_hdr(inode); ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), ext4_idx_pblock(EXT_FIRST_INDEX(neh))); neh->eh_depth = cpu_to_le16(path->p_depth + 1); err = ext4_ext_dirty(handle, inode, curp); out: brelse(bh); return err; } /* * ext4_ext_create_new_leaf: * finds empty index and adds new leaf. * if no free index is found, then it requests in-depth growing. */ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, unsigned int flags, struct ext4_ext_path *path, struct ext4_extent *newext) { struct ext4_ext_path *curp; int depth, i, err = 0; repeat: i = depth = ext_depth(inode); /* walk up to the tree and look for free index entry */ curp = path + depth; while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { i--; curp--; } /* we use already allocated block for index block, * so subsequent data blocks should be contiguous */ if (EXT_HAS_FREE_INDEX(curp)) { /* if we found index with free entry, then use that * entry: create all needed subtree and add new leaf */ err = ext4_ext_split(handle, inode, flags, path, newext, i); if (err) goto out; /* refill path */ ext4_ext_drop_refs(path); path = ext4_ext_find_extent(inode, (ext4_lblk_t)le32_to_cpu(newext->ee_block), path); if (IS_ERR(path)) err = PTR_ERR(path); } else { /* tree is full, time to grow in depth */ err = ext4_ext_grow_indepth(handle, inode, flags, path, newext); if (err) goto out; /* refill path */ ext4_ext_drop_refs(path); path = ext4_ext_find_extent(inode, (ext4_lblk_t)le32_to_cpu(newext->ee_block), path); if (IS_ERR(path)) { err = PTR_ERR(path); goto out; } /* * only first (depth 0 -> 1) produces free space; * in all other cases we have to split the grown tree */ depth = ext_depth(inode); if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { /* now we need to split */ goto repeat; } } out: return err; } /* * search the closest allocated block to the left for *logical * and returns it at @logical + it's physical address at @phys * if *logical is the smallest allocated block, the function * returns 0 at @phys * return value contains 0 (success) or error code */ static int ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *logical, ext4_fsblk_t *phys) { struct ext4_extent_idx *ix; struct ext4_extent *ex; int depth, ee_len; if (unlikely(path == NULL)) { EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); return -EIO; } depth = path->p_depth; *phys = 0; if (depth == 0 && path->p_ext == NULL) return 0; /* usually extent in the path covers blocks smaller * then *logical, but it can be that extent is the * first one in the file */ ex = path[depth].p_ext; ee_len = ext4_ext_get_actual_len(ex); if (*logical < le32_to_cpu(ex->ee_block)) { if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { EXT4_ERROR_INODE(inode, "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", *logical, le32_to_cpu(ex->ee_block)); return -EIO; } while (--depth >= 0) { ix = path[depth].p_idx; if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { EXT4_ERROR_INODE(inode, "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", ix != NULL ? ix->ei_block : 0, EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block : 0, depth); return -EIO; } } return 0; } if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { EXT4_ERROR_INODE(inode, "logical %d < ee_block %d + ee_len %d!", *logical, le32_to_cpu(ex->ee_block), ee_len); return -EIO; } *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; *phys = ext4_ext_pblock(ex) + ee_len - 1; return 0; } /* * search the closest allocated block to the right for *logical * and returns it at @logical + it's physical address at @phys * if *logical is the smallest allocated block, the function * returns 0 at @phys * return value contains 0 (success) or error code */ static int ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *logical, ext4_fsblk_t *phys) { struct buffer_head *bh = NULL; struct ext4_extent_header *eh; struct ext4_extent_idx *ix; struct ext4_extent *ex; ext4_fsblk_t block; int depth; /* Note, NOT eh_depth; depth from top of tree */ int ee_len; if (unlikely(path == NULL)) { EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); return -EIO; } depth = path->p_depth; *phys = 0; if (depth == 0 && path->p_ext == NULL) return 0; /* usually extent in the path covers blocks smaller * then *logical, but it can be that extent is the * first one in the file */ ex = path[depth].p_ext; ee_len = ext4_ext_get_actual_len(ex); if (*logical < le32_to_cpu(ex->ee_block)) { if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { EXT4_ERROR_INODE(inode, "first_extent(path[%d].p_hdr) != ex", depth); return -EIO; } while (--depth >= 0) { ix = path[depth].p_idx; if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { EXT4_ERROR_INODE(inode, "ix != EXT_FIRST_INDEX *logical %d!", *logical); return -EIO; } } *logical = le32_to_cpu(ex->ee_block); *phys = ext4_ext_pblock(ex); return 0; } if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { EXT4_ERROR_INODE(inode, "logical %d < ee_block %d + ee_len %d!", *logical, le32_to_cpu(ex->ee_block), ee_len); return -EIO; } if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { /* next allocated block in this leaf */ ex++; *logical = le32_to_cpu(ex->ee_block); *phys = ext4_ext_pblock(ex); return 0; } /* go up and search for index to the right */ while (--depth >= 0) { ix = path[depth].p_idx; if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) goto got_index; } /* we've gone up to the root and found no index to the right */ return 0; got_index: /* we've found index to the right, let's * follow it and find the closest allocated * block to the right */ ix++; block = ext4_idx_pblock(ix); while (++depth < path->p_depth) { bh = sb_bread(inode->i_sb, block); if (bh == NULL) return -EIO; eh = ext_block_hdr(bh); /* subtract from p_depth to get proper eh_depth */ if (ext4_ext_check(inode, eh, path->p_depth - depth)) { put_bh(bh); return -EIO; } ix = EXT_FIRST_INDEX(eh); block = ext4_idx_pblock(ix); put_bh(bh); } bh = sb_bread(inode->i_sb, block); if (bh == NULL) return -EIO; eh = ext_block_hdr(bh); if (ext4_ext_check(inode, eh, path->p_depth - depth)) { put_bh(bh); return -EIO; } ex = EXT_FIRST_EXTENT(eh); *logical = le32_to_cpu(ex->ee_block); *phys = ext4_ext_pblock(ex); put_bh(bh); return 0; } /* * ext4_ext_next_allocated_block: * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. * NOTE: it considers block number from index entry as * allocated block. Thus, index entries have to be consistent * with leaves. */ static ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path) { int depth; BUG_ON(path == NULL); depth = path->p_depth; if (depth == 0 && path->p_ext == NULL) return EXT_MAX_BLOCKS; while (depth >= 0) { if (depth == path->p_depth) { /* leaf */ if (path[depth].p_ext != EXT_LAST_EXTENT(path[depth].p_hdr)) return le32_to_cpu(path[depth].p_ext[1].ee_block); } else { /* index */ if (path[depth].p_idx != EXT_LAST_INDEX(path[depth].p_hdr)) return le32_to_cpu(path[depth].p_idx[1].ei_block); } depth--; } return EXT_MAX_BLOCKS; } /* * ext4_ext_next_leaf_block: * returns first allocated block from next leaf or EXT_MAX_BLOCKS */ static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) { int depth; BUG_ON(path == NULL); depth = path->p_depth; /* zero-tree has no leaf blocks at all */ if (depth == 0) return EXT_MAX_BLOCKS; /* go to index block */ depth--; while (depth >= 0) { if (path[depth].p_idx != EXT_LAST_INDEX(path[depth].p_hdr)) return (ext4_lblk_t) le32_to_cpu(path[depth].p_idx[1].ei_block); depth--; } return EXT_MAX_BLOCKS; } /* * ext4_ext_correct_indexes: * if leaf gets modified and modified extent is first in the leaf, * then we have to correct all indexes above. * TODO: do we need to correct tree in all cases? */ static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { struct ext4_extent_header *eh; int depth = ext_depth(inode); struct ext4_extent *ex; __le32 border; int k, err = 0; eh = path[depth].p_hdr; ex = path[depth].p_ext; if (unlikely(ex == NULL || eh == NULL)) { EXT4_ERROR_INODE(inode, "ex %p == NULL or eh %p == NULL", ex, eh); return -EIO; } if (depth == 0) { /* there is no tree at all */ return 0; } if (ex != EXT_FIRST_EXTENT(eh)) { /* we correct tree if first leaf got modified only */ return 0; } /* * TODO: we need correction if border is smaller than current one */ k = depth - 1; border = path[depth].p_ext->ee_block; err = ext4_ext_get_access(handle, inode, path + k); if (err) return err; path[k].p_idx->ei_block = border; err = ext4_ext_dirty(handle, inode, path + k); if (err) return err; while (k--) { /* change all left-side indexes */ if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) break; err = ext4_ext_get_access(handle, inode, path + k); if (err) break; path[k].p_idx->ei_block = border; err = ext4_ext_dirty(handle, inode, path + k); if (err) break; } return err; } int ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, struct ext4_extent *ex2) { unsigned short ext1_ee_len, ext2_ee_len, max_len; /* * Make sure that either both extents are uninitialized, or * both are _not_. */ if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2)) return 0; if (ext4_ext_is_uninitialized(ex1)) max_len = EXT_UNINIT_MAX_LEN; else max_len = EXT_INIT_MAX_LEN; ext1_ee_len = ext4_ext_get_actual_len(ex1); ext2_ee_len = ext4_ext_get_actual_len(ex2); if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != le32_to_cpu(ex2->ee_block)) return 0; /* * To allow future support for preallocated extents to be added * as an RO_COMPAT feature, refuse to merge to extents if * this can result in the top bit of ee_len being set. */ if (ext1_ee_len + ext2_ee_len > max_len) return 0; #ifdef AGGRESSIVE_TEST if (ext1_ee_len >= 4) return 0; #endif if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) return 1; return 0; } /* * This function tries to merge the "ex" extent to the next extent in the tree. * It always tries to merge towards right. If you want to merge towards * left, pass "ex - 1" as argument instead of "ex". * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns * 1 if they got merged. */ static int ext4_ext_try_to_merge_right(struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex) { struct ext4_extent_header *eh; unsigned int depth, len; int merge_done = 0; int uninitialized = 0; depth = ext_depth(inode); BUG_ON(path[depth].p_hdr == NULL); eh = path[depth].p_hdr; while (ex < EXT_LAST_EXTENT(eh)) { if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) break; /* merge with next extent! */ if (ext4_ext_is_uninitialized(ex)) uninitialized = 1; ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + ext4_ext_get_actual_len(ex + 1)); if (uninitialized) ext4_ext_mark_uninitialized(ex); if (ex + 1 < EXT_LAST_EXTENT(eh)) { len = (EXT_LAST_EXTENT(eh) - ex - 1) * sizeof(struct ext4_extent); memmove(ex + 1, ex + 2, len); } le16_add_cpu(&eh->eh_entries, -1); merge_done = 1; WARN_ON(eh->eh_entries == 0); if (!eh->eh_entries) EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); } return merge_done; } /* * This function tries to merge the @ex extent to neighbours in the tree. * return 1 if merge left else 0. */ static int ext4_ext_try_to_merge(struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex) { struct ext4_extent_header *eh; unsigned int depth; int merge_done = 0; int ret = 0; depth = ext_depth(inode); BUG_ON(path[depth].p_hdr == NULL); eh = path[depth].p_hdr; if (ex > EXT_FIRST_EXTENT(eh)) merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); if (!merge_done) ret = ext4_ext_try_to_merge_right(inode, path, ex); return ret; } /* * check if a portion of the "newext" extent overlaps with an * existing extent. * * If there is an overlap discovered, it updates the length of the newext * such that there will be no overlap, and then returns 1. * If there is no overlap found, it returns 0. */ static unsigned int ext4_ext_check_overlap(struct inode *inode, struct ext4_extent *newext, struct ext4_ext_path *path) { ext4_lblk_t b1, b2; unsigned int depth, len1; unsigned int ret = 0; b1 = le32_to_cpu(newext->ee_block); len1 = ext4_ext_get_actual_len(newext); depth = ext_depth(inode); if (!path[depth].p_ext) goto out; b2 = le32_to_cpu(path[depth].p_ext->ee_block); /* * get the next allocated block if the extent in the path * is before the requested block(s) */ if (b2 < b1) { b2 = ext4_ext_next_allocated_block(path); if (b2 == EXT_MAX_BLOCKS) goto out; } /* check for wrap through zero on extent logical start block*/ if (b1 + len1 < b1) { len1 = EXT_MAX_BLOCKS - b1; newext->ee_len = cpu_to_le16(len1); ret = 1; } /* check for overlap */ if (b1 + len1 > b2) { newext->ee_len = cpu_to_le16(b2 - b1); ret = 1; } out: return ret; } /* * ext4_ext_insert_extent: * tries to merge requsted extent into the existing extent or * inserts requested extent as new one into the tree, * creating new leaf in the no-space case. */ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *newext, int flag) { struct ext4_extent_header *eh; struct ext4_extent *ex, *fex; struct ext4_extent *nearex; /* nearest extent */ struct ext4_ext_path *npath = NULL; int depth, len, err; ext4_lblk_t next; unsigned uninitialized = 0; int flags = 0; if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); return -EIO; } depth = ext_depth(inode); ex = path[depth].p_ext; if (unlikely(path[depth].p_hdr == NULL)) { EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); return -EIO; } /* try to insert block into found extent and return */ if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO) && ext4_can_extents_be_merged(inode, ex, newext)) { ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n", ext4_ext_is_uninitialized(newext), ext4_ext_get_actual_len(newext), le32_to_cpu(ex->ee_block), ext4_ext_is_uninitialized(ex), ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); err = ext4_ext_get_access(handle, inode, path + depth); if (err) return err; /* * ext4_can_extents_be_merged should have checked that either * both extents are uninitialized, or both aren't. Thus we * need to check only one of them here. */ if (ext4_ext_is_uninitialized(ex)) uninitialized = 1; ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + ext4_ext_get_actual_len(newext)); if (uninitialized) ext4_ext_mark_uninitialized(ex); eh = path[depth].p_hdr; nearex = ex; goto merge; } depth = ext_depth(inode); eh = path[depth].p_hdr; if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) goto has_space; /* probably next leaf has space for us? */ fex = EXT_LAST_EXTENT(eh); next = EXT_MAX_BLOCKS; if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)) next = ext4_ext_next_leaf_block(path); if (next != EXT_MAX_BLOCKS) { ext_debug("next leaf block - %d\n", next); BUG_ON(npath != NULL); npath = ext4_ext_find_extent(inode, next, NULL); if (IS_ERR(npath)) return PTR_ERR(npath); BUG_ON(npath->p_depth != path->p_depth); eh = npath[depth].p_hdr; if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { ext_debug("next leaf isn't full(%d)\n", le16_to_cpu(eh->eh_entries)); path = npath; goto has_space; } ext_debug("next leaf has no free space(%d,%d)\n", le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); } /* * There is no free space in the found leaf. * We're gonna add a new leaf in the tree. */ if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) flags = EXT4_MB_USE_ROOT_BLOCKS; err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext); if (err) goto cleanup; depth = ext_depth(inode); eh = path[depth].p_hdr; has_space: nearex = path[depth].p_ext; err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto cleanup; if (!nearex) { /* there is no extent in this leaf, create first one */ ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n", le32_to_cpu(newext->ee_block), ext4_ext_pblock(newext), ext4_ext_is_uninitialized(newext), ext4_ext_get_actual_len(newext)); path[depth].p_ext = EXT_FIRST_EXTENT(eh); } else if (le32_to_cpu(newext->ee_block) > le32_to_cpu(nearex->ee_block)) { /* BUG_ON(newext->ee_block == nearex->ee_block); */ if (nearex != EXT_LAST_EXTENT(eh)) { len = EXT_MAX_EXTENT(eh) - nearex; len = (len - 1) * sizeof(struct ext4_extent); len = len < 0 ? 0 : len; ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, " "move %d from 0x%p to 0x%p\n", le32_to_cpu(newext->ee_block), ext4_ext_pblock(newext), ext4_ext_is_uninitialized(newext), ext4_ext_get_actual_len(newext), nearex, len, nearex + 1, nearex + 2); memmove(nearex + 2, nearex + 1, len); } path[depth].p_ext = nearex + 1; } else { BUG_ON(newext->ee_block == nearex->ee_block); len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); len = len < 0 ? 0 : len; ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, " "move %d from 0x%p to 0x%p\n", le32_to_cpu(newext->ee_block), ext4_ext_pblock(newext), ext4_ext_is_uninitialized(newext), ext4_ext_get_actual_len(newext), nearex, len, nearex, nearex + 1); memmove(nearex + 1, nearex, len); path[depth].p_ext = nearex; } le16_add_cpu(&eh->eh_entries, 1); nearex = path[depth].p_ext; nearex->ee_block = newext->ee_block; ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); nearex->ee_len = newext->ee_len; merge: /* try to merge extents to the right */ if (!(flag & EXT4_GET_BLOCKS_PRE_IO)) ext4_ext_try_to_merge(inode, path, nearex); /* try to merge extents to the left */ /* time to correct all indexes above */ err = ext4_ext_correct_indexes(handle, inode, path); if (err) goto cleanup; err = ext4_ext_dirty(handle, inode, path + depth); cleanup: if (npath) { ext4_ext_drop_refs(npath); kfree(npath); } ext4_ext_invalidate_cache(inode); return err; } static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block, ext4_lblk_t num, ext_prepare_callback func, void *cbdata) { struct ext4_ext_path *path = NULL; struct ext4_ext_cache cbex; struct ext4_extent *ex; ext4_lblk_t next, start = 0, end = 0; ext4_lblk_t last = block + num; int depth, exists, err = 0; BUG_ON(func == NULL); BUG_ON(inode == NULL); while (block < last && block != EXT_MAX_BLOCKS) { num = last - block; /* find extent for this block */ down_read(&EXT4_I(inode)->i_data_sem); path = ext4_ext_find_extent(inode, block, path); up_read(&EXT4_I(inode)->i_data_sem); if (IS_ERR(path)) { err = PTR_ERR(path); path = NULL; break; } depth = ext_depth(inode); if (unlikely(path[depth].p_hdr == NULL)) { EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); err = -EIO; break; } ex = path[depth].p_ext; next = ext4_ext_next_allocated_block(path); exists = 0; if (!ex) { /* there is no extent yet, so try to allocate * all requested space */ start = block; end = block + num; } else if (le32_to_cpu(ex->ee_block) > block) { /* need to allocate space before found extent */ start = block; end = le32_to_cpu(ex->ee_block); if (block + num < end) end = block + num; } else if (block >= le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex)) { /* need to allocate space after found extent */ start = block; end = block + num; if (end >= next) end = next; } else if (block >= le32_to_cpu(ex->ee_block)) { /* * some part of requested space is covered * by found extent */ start = block; end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); if (block + num < end) end = block + num; exists = 1; } else { BUG(); } BUG_ON(end <= start); if (!exists) { cbex.ec_block = start; cbex.ec_len = end - start; cbex.ec_start = 0; } else { cbex.ec_block = le32_to_cpu(ex->ee_block); cbex.ec_len = ext4_ext_get_actual_len(ex); cbex.ec_start = ext4_ext_pblock(ex); } if (unlikely(cbex.ec_len == 0)) { EXT4_ERROR_INODE(inode, "cbex.ec_len == 0"); err = -EIO; break; } err = func(inode, next, &cbex, ex, cbdata); ext4_ext_drop_refs(path); if (err < 0) break; if (err == EXT_REPEAT) continue; else if (err == EXT_BREAK) { err = 0; break; } if (ext_depth(inode) != depth) { /* depth was changed. we have to realloc path */ kfree(path); path = NULL; } block = cbex.ec_block + cbex.ec_len; } if (path) { ext4_ext_drop_refs(path); kfree(path); } return err; } static void ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, __u32 len, ext4_fsblk_t start) { struct ext4_ext_cache *cex; BUG_ON(len == 0); spin_lock(&EXT4_I(inode)->i_block_reservation_lock); cex = &EXT4_I(inode)->i_cached_extent; cex->ec_block = block; cex->ec_len = len; cex->ec_start = start; spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); } /* * ext4_ext_put_gap_in_cache: * calculate boundaries of the gap that the requested block fits into * and cache this gap */ static void ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { int depth = ext_depth(inode); unsigned long len; ext4_lblk_t lblock; struct ext4_extent *ex; ex = path[depth].p_ext; if (ex == NULL) { /* there is no extent yet, so gap is [0;-] */ lblock = 0; len = EXT_MAX_BLOCKS; ext_debug("cache gap(whole file):"); } else if (block < le32_to_cpu(ex->ee_block)) { lblock = block; len = le32_to_cpu(ex->ee_block) - block; ext_debug("cache gap(before): %u [%u:%u]", block, le32_to_cpu(ex->ee_block), ext4_ext_get_actual_len(ex)); } else if (block >= le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex)) { ext4_lblk_t next; lblock = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); next = ext4_ext_next_allocated_block(path); ext_debug("cache gap(after): [%u:%u] %u", le32_to_cpu(ex->ee_block), ext4_ext_get_actual_len(ex), block); BUG_ON(next == lblock); len = next - lblock; } else { lblock = len = 0; BUG(); } ext_debug(" -> %u:%lu\n", lblock, len); ext4_ext_put_in_cache(inode, lblock, len, 0); } /* * ext4_ext_check_cache() * Checks to see if the given block is in the cache. * If it is, the cached extent is stored in the given * cache extent pointer. If the cached extent is a hole, * this routine should be used instead of * ext4_ext_in_cache if the calling function needs to * know the size of the hole. * * @inode: The files inode * @block: The block to look for in the cache * @ex: Pointer where the cached extent will be stored * if it contains block * * Return 0 if cache is invalid; 1 if the cache is valid */ static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block, struct ext4_ext_cache *ex){ struct ext4_ext_cache *cex; struct ext4_sb_info *sbi; int ret = 0; /* * We borrow i_block_reservation_lock to protect i_cached_extent */ spin_lock(&EXT4_I(inode)->i_block_reservation_lock); cex = &EXT4_I(inode)->i_cached_extent; sbi = EXT4_SB(inode->i_sb); /* has cache valid data? */ if (cex->ec_len == 0) goto errout; if (in_range(block, cex->ec_block, cex->ec_len)) { memcpy(ex, cex, sizeof(struct ext4_ext_cache)); ext_debug("%u cached by %u:%u:%llu\n", block, cex->ec_block, cex->ec_len, cex->ec_start); ret = 1; } errout: if (!ret) sbi->extent_cache_misses++; else sbi->extent_cache_hits++; spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); return ret; } /* * ext4_ext_in_cache() * Checks to see if the given block is in the cache. * If it is, the cached extent is stored in the given * extent pointer. * * @inode: The files inode * @block: The block to look for in the cache * @ex: Pointer where the cached extent will be stored * if it contains block * * Return 0 if cache is invalid; 1 if the cache is valid */ static int ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, struct ext4_extent *ex) { struct ext4_ext_cache cex; int ret = 0; if (ext4_ext_check_cache(inode, block, &cex)) { ex->ee_block = cpu_to_le32(cex.ec_block); ext4_ext_store_pblock(ex, cex.ec_start); ex->ee_len = cpu_to_le16(cex.ec_len); ret = 1; } return ret; } /* * ext4_ext_rm_idx: * removes index from the index block. */ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { int err; ext4_fsblk_t leaf; /* free index block */ path--; leaf = ext4_idx_pblock(path->p_idx); if (unlikely(path->p_hdr->eh_entries == 0)) { EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); return -EIO; } err = ext4_ext_get_access(handle, inode, path); if (err) return err; if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) { int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx; len *= sizeof(struct ext4_extent_idx); memmove(path->p_idx, path->p_idx + 1, len); } le16_add_cpu(&path->p_hdr->eh_entries, -1); err = ext4_ext_dirty(handle, inode, path); if (err) return err; ext_debug("index is empty, remove it, free block %llu\n", leaf); ext4_free_blocks(handle, inode, NULL, leaf, 1, EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); return err; } /* * ext4_ext_calc_credits_for_single_extent: * This routine returns max. credits that needed to insert an extent * to the extent tree. * When pass the actual path, the caller should calculate credits * under i_data_sem. */ int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, struct ext4_ext_path *path) { if (path) { int depth = ext_depth(inode); int ret = 0; /* probably there is space in leaf? */ if (le16_to_cpu(path[depth].p_hdr->eh_entries) < le16_to_cpu(path[depth].p_hdr->eh_max)) { /* * There are some space in the leaf tree, no * need to account for leaf block credit * * bitmaps and block group descriptor blocks * and other metadat blocks still need to be * accounted. */ /* 1 bitmap, 1 block group descriptor */ ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); return ret; } } return ext4_chunk_trans_blocks(inode, nrblocks); } /* * How many index/leaf blocks need to change/allocate to modify nrblocks? * * if nrblocks are fit in a single extent (chunk flag is 1), then * in the worse case, each tree level index/leaf need to be changed * if the tree split due to insert a new extent, then the old tree * index/leaf need to be updated too * * If the nrblocks are discontiguous, they could cause * the whole tree split more than once, but this is really rare. */ int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) { int index; int depth = ext_depth(inode); if (chunk) index = depth * 2; else index = depth * 3; return index; } static int ext4_remove_blocks(handle_t *handle, struct inode *inode, struct ext4_extent *ex, ext4_lblk_t from, ext4_lblk_t to) { unsigned short ee_len = ext4_ext_get_actual_len(ex); int flags = EXT4_FREE_BLOCKS_FORGET; if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) flags |= EXT4_FREE_BLOCKS_METADATA; #ifdef EXTENTS_STATS { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); spin_lock(&sbi->s_ext_stats_lock); sbi->s_ext_blocks += ee_len; sbi->s_ext_extents++; if (ee_len < sbi->s_ext_min) sbi->s_ext_min = ee_len; if (ee_len > sbi->s_ext_max) sbi->s_ext_max = ee_len; if (ext_depth(inode) > sbi->s_depth_max) sbi->s_depth_max = ext_depth(inode); spin_unlock(&sbi->s_ext_stats_lock); } #endif if (from >= le32_to_cpu(ex->ee_block) && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { /* tail removal */ ext4_lblk_t num; ext4_fsblk_t start; num = le32_to_cpu(ex->ee_block) + ee_len - from; start = ext4_ext_pblock(ex) + ee_len - num; ext_debug("free last %u blocks starting %llu\n", num, start); ext4_free_blocks(handle, inode, NULL, start, num, flags); } else if (from == le32_to_cpu(ex->ee_block) && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { /* head removal */ ext4_lblk_t num; ext4_fsblk_t start; num = to - from; start = ext4_ext_pblock(ex); ext_debug("free first %u blocks starting %llu\n", num, start); ext4_free_blocks(handle, inode, 0, start, num, flags); } else { printk(KERN_INFO "strange request: removal(2) " "%u-%u from %u:%u\n", from, to, le32_to_cpu(ex->ee_block), ee_len); } return 0; } /* * ext4_ext_rm_leaf() Removes the extents associated with the * blocks appearing between "start" and "end", and splits the extents * if "start" and "end" appear in the same extent * * @handle: The journal handle * @inode: The files inode * @path: The path to the leaf * @start: The first block to remove * @end: The last block to remove */ static int ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t start, ext4_lblk_t end) { int err = 0, correct_index = 0; int depth = ext_depth(inode), credits; struct ext4_extent_header *eh; ext4_lblk_t a, b, block; unsigned num; ext4_lblk_t ex_ee_block; unsigned short ex_ee_len; unsigned uninitialized = 0; struct ext4_extent *ex; struct ext4_map_blocks map; /* the header must be checked already in ext4_ext_remove_space() */ ext_debug("truncate since %u in leaf\n", start); if (!path[depth].p_hdr) path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); eh = path[depth].p_hdr; if (unlikely(path[depth].p_hdr == NULL)) { EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); return -EIO; } /* find where to start removing */ ex = EXT_LAST_EXTENT(eh); ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); while (ex >= EXT_FIRST_EXTENT(eh) && ex_ee_block + ex_ee_len > start) { if (ext4_ext_is_uninitialized(ex)) uninitialized = 1; else uninitialized = 0; ext_debug("remove ext %u:[%d]%d\n", ex_ee_block, uninitialized, ex_ee_len); path[depth].p_ext = ex; a = ex_ee_block > start ? ex_ee_block : start; b = ex_ee_block+ex_ee_len - 1 < end ? ex_ee_block+ex_ee_len - 1 : end; ext_debug(" border %u:%u\n", a, b); /* If this extent is beyond the end of the hole, skip it */ if (end <= ex_ee_block) { ex--; ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); continue; } else if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { /* * If this is a truncate, then this condition should * never happen because at least one of the end points * needs to be on the edge of the extent. */ if (end == EXT_MAX_BLOCKS - 1) { ext_debug(" bad truncate %u:%u\n", start, end); block = 0; num = 0; err = -EIO; goto out; } /* * else this is a hole punch, so the extent needs to * be split since neither edge of the hole is on the * extent edge */ else{ map.m_pblk = ext4_ext_pblock(ex); map.m_lblk = ex_ee_block; map.m_len = b - ex_ee_block; err = ext4_split_extent(handle, inode, path, &map, 0, EXT4_GET_BLOCKS_PUNCH_OUT_EXT | EXT4_GET_BLOCKS_PRE_IO); if (err < 0) goto out; ex_ee_len = ext4_ext_get_actual_len(ex); b = ex_ee_block+ex_ee_len - 1 < end ? ex_ee_block+ex_ee_len - 1 : end; /* Then remove tail of this extent */ block = ex_ee_block; num = a - block; } } else if (a != ex_ee_block) { /* remove tail of the extent */ block = ex_ee_block; num = a - block; } else if (b != ex_ee_block + ex_ee_len - 1) { /* remove head of the extent */ block = b; num = ex_ee_block + ex_ee_len - b; /* * If this is a truncate, this condition * should never happen */ if (end == EXT_MAX_BLOCKS - 1) { ext_debug(" bad truncate %u:%u\n", start, end); err = -EIO; goto out; } } else { /* remove whole extent: excellent! */ block = ex_ee_block; num = 0; if (a != ex_ee_block) { ext_debug(" bad truncate %u:%u\n", start, end); err = -EIO; goto out; } if (b != ex_ee_block + ex_ee_len - 1) { ext_debug(" bad truncate %u:%u\n", start, end); err = -EIO; goto out; } } /* * 3 for leaf, sb, and inode plus 2 (bmap and group * descriptor) for each block group; assume two block * groups plus ex_ee_len/blocks_per_block_group for * the worst case */ credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); if (ex == EXT_FIRST_EXTENT(eh)) { correct_index = 1; credits += (ext_depth(inode)) + 1; } credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); err = ext4_ext_truncate_extend_restart(handle, inode, credits); if (err) goto out; err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; err = ext4_remove_blocks(handle, inode, ex, a, b); if (err) goto out; if (num == 0) { /* this extent is removed; mark slot entirely unused */ ext4_ext_store_pblock(ex, 0); } else if (block != ex_ee_block) { /* * If this was a head removal, then we need to update * the physical block since it is now at a different * location */ ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a)); } ex->ee_block = cpu_to_le32(block); ex->ee_len = cpu_to_le16(num); /* * Do not mark uninitialized if all the blocks in the * extent have been removed. */ if (uninitialized && num) ext4_ext_mark_uninitialized(ex); err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto out; /* * If the extent was completely released, * we need to remove it from the leaf */ if (num == 0) { if (end != EXT_MAX_BLOCKS - 1) { /* * For hole punching, we need to scoot all the * extents up when an extent is removed so that * we dont have blank extents in the middle */ memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * sizeof(struct ext4_extent)); /* Now get rid of the one at the end */ memset(EXT_LAST_EXTENT(eh), 0, sizeof(struct ext4_extent)); } le16_add_cpu(&eh->eh_entries, -1); } ext_debug("new extent: %u:%u:%llu\n", block, num, ext4_ext_pblock(ex)); ex--; ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); } if (correct_index && eh->eh_entries) err = ext4_ext_correct_indexes(handle, inode, path); /* if this leaf is free, then we should * remove it from index block above */ if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) err = ext4_ext_rm_idx(handle, inode, path + depth); out: return err; } /* * ext4_ext_more_to_rm: * returns 1 if current index has to be freed (even partial) */ static int ext4_ext_more_to_rm(struct ext4_ext_path *path) { BUG_ON(path->p_idx == NULL); if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) return 0; /* * if truncate on deeper level happened, it wasn't partial, * so we have to consider current index for truncation */ if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) return 0; return 1; } static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) { struct super_block *sb = inode->i_sb; int depth = ext_depth(inode); struct ext4_ext_path *path; handle_t *handle; int i, err; ext_debug("truncate since %u\n", start); /* probably first extent we're gonna free will be last in block */ handle = ext4_journal_start(inode, depth + 1); if (IS_ERR(handle)) return PTR_ERR(handle); again: ext4_ext_invalidate_cache(inode); /* * We start scanning from right side, freeing all the blocks * after i_size and walking into the tree depth-wise. */ depth = ext_depth(inode); path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS); if (path == NULL) { ext4_journal_stop(handle); return -ENOMEM; } path[0].p_depth = depth; path[0].p_hdr = ext_inode_hdr(inode); if (ext4_ext_check(inode, path[0].p_hdr, depth)) { err = -EIO; goto out; } i = err = 0; while (i >= 0 && err == 0) { if (i == depth) { /* this is leaf block */ err = ext4_ext_rm_leaf(handle, inode, path, start, EXT_MAX_BLOCKS - 1); /* root level has p_bh == NULL, brelse() eats this */ brelse(path[i].p_bh); path[i].p_bh = NULL; i--; continue; } /* this is index block */ if (!path[i].p_hdr) { ext_debug("initialize header\n"); path[i].p_hdr = ext_block_hdr(path[i].p_bh); } if (!path[i].p_idx) { /* this level hasn't been touched yet */ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; ext_debug("init index ptr: hdr 0x%p, num %d\n", path[i].p_hdr, le16_to_cpu(path[i].p_hdr->eh_entries)); } else { /* we were already here, see at next index */ path[i].p_idx--; } ext_debug("level %d - index, first 0x%p, cur 0x%p\n", i, EXT_FIRST_INDEX(path[i].p_hdr), path[i].p_idx); if (ext4_ext_more_to_rm(path + i)) { struct buffer_head *bh; /* go to the next level */ ext_debug("move to level %d (block %llu)\n", i + 1, ext4_idx_pblock(path[i].p_idx)); memset(path + i + 1, 0, sizeof(*path)); bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx)); if (!bh) { /* should we reset i_size? */ err = -EIO; break; } if (WARN_ON(i + 1 > depth)) { err = -EIO; break; } if (ext4_ext_check(inode, ext_block_hdr(bh), depth - i - 1)) { err = -EIO; break; } path[i + 1].p_bh = bh; /* save actual number of indexes since this * number is changed at the next iteration */ path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); i++; } else { /* we finished processing this index, go up */ if (path[i].p_hdr->eh_entries == 0 && i > 0) { /* index is empty, remove it; * handle must be already prepared by the * truncatei_leaf() */ err = ext4_ext_rm_idx(handle, inode, path + i); } /* root level has p_bh == NULL, brelse() eats this */ brelse(path[i].p_bh); path[i].p_bh = NULL; i--; ext_debug("return to level %d\n", i); } } /* TODO: flexible tree reduction should be here */ if (path->p_hdr->eh_entries == 0) { /* * truncate to zero freed all the tree, * so we need to correct eh_depth */ err = ext4_ext_get_access(handle, inode, path); if (err == 0) { ext_inode_hdr(inode)->eh_depth = 0; ext_inode_hdr(inode)->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); err = ext4_ext_dirty(handle, inode, path); } } out: ext4_ext_drop_refs(path); kfree(path); if (err == -EAGAIN) goto again; ext4_journal_stop(handle); return err; } /* * called at mount time */ void ext4_ext_init(struct super_block *sb) { /* * possible initialization would be here */ if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) printk(KERN_INFO "EXT4-fs: file extents enabled"); #ifdef AGGRESSIVE_TEST printk(", aggressive tests"); #endif #ifdef CHECK_BINSEARCH printk(", check binsearch"); #endif #ifdef EXTENTS_STATS printk(", stats"); #endif printk("\n"); #endif #ifdef EXTENTS_STATS spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); EXT4_SB(sb)->s_ext_min = 1 << 30; EXT4_SB(sb)->s_ext_max = 0; #endif } } /* * called at umount time */ void ext4_ext_release(struct super_block *sb) { if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) return; #ifdef EXTENTS_STATS if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { struct ext4_sb_info *sbi = EXT4_SB(sb); printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", sbi->s_ext_blocks, sbi->s_ext_extents, sbi->s_ext_blocks / sbi->s_ext_extents); printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); } #endif } /* FIXME!! we need to try to merge to left or right after zero-out */ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) { ext4_fsblk_t ee_pblock; unsigned int ee_len; int ret; ee_len = ext4_ext_get_actual_len(ex); ee_pblock = ext4_ext_pblock(ex); ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS); if (ret > 0) ret = 0; return ret; } /* * used by extent splitting. */ #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ due to ENOSPC */ #define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */ #define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */ /* * ext4_split_extent_at() splits an extent at given block. * * @handle: the journal handle * @inode: the file inode * @path: the path to the extent * @split: the logical block where the extent is splitted. * @split_flags: indicates if the extent could be zeroout if split fails, and * the states(init or uninit) of new extents. * @flags: flags used to insert new extent to extent tree. * * * Splits extent [a, b] into two extents [a, @split) and [@split, b], states * of which are deterimined by split_flag. * * There are two cases: * a> the extent are splitted into two extent. * b> split is not needed, and just mark the extent. * * return 0 on success. */ static int ext4_split_extent_at(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t split, int split_flag, int flags) { ext4_fsblk_t newblock; ext4_lblk_t ee_block; struct ext4_extent *ex, newex, orig_ex; struct ext4_extent *ex2 = NULL; unsigned int ee_len, depth; int err = 0; ext_debug("ext4_split_extents_at: inode %lu, logical" "block %llu\n", inode->i_ino, (unsigned long long)split); ext4_ext_show_leaf(inode, path); depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); newblock = split - ee_block + ext4_ext_pblock(ex); BUG_ON(split < ee_block || split >= (ee_block + ee_len)); err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; if (split == ee_block) { /* * case b: block @split is the block that the extent begins with * then we just change the state of the extent, and splitting * is not needed. */ if (split_flag & EXT4_EXT_MARK_UNINIT2) ext4_ext_mark_uninitialized(ex); else ext4_ext_mark_initialized(ex); if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) ext4_ext_try_to_merge(inode, path, ex); err = ext4_ext_dirty(handle, inode, path + depth); goto out; } /* case a */ memcpy(&orig_ex, ex, sizeof(orig_ex)); ex->ee_len = cpu_to_le16(split - ee_block); if (split_flag & EXT4_EXT_MARK_UNINIT1) ext4_ext_mark_uninitialized(ex); /* * path may lead to new leaf, not to original leaf any more * after ext4_ext_insert_extent() returns, */ err = ext4_ext_dirty(handle, inode, path + depth); if (err) goto fix_extent_len; ex2 = &newex; ex2->ee_block = cpu_to_le32(split); ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block)); ext4_ext_store_pblock(ex2, newblock); if (split_flag & EXT4_EXT_MARK_UNINIT2) ext4_ext_mark_uninitialized(ex2); err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { err = ext4_ext_zeroout(inode, &orig_ex); if (err) goto fix_extent_len; /* update the extent length and mark as initialized */ ex->ee_len = cpu_to_le32(ee_len); ext4_ext_try_to_merge(inode, path, ex); err = ext4_ext_dirty(handle, inode, path + depth); goto out; } else if (err) goto fix_extent_len; out: ext4_ext_show_leaf(inode, path); return err; fix_extent_len: ex->ee_len = orig_ex.ee_len; ext4_ext_dirty(handle, inode, path + depth); return err; } /* * ext4_split_extents() splits an extent and mark extent which is covered * by @map as split_flags indicates * * It may result in splitting the extent into multiple extents (upto three) * There are three possibilities: * a> There is no split required * b> Splits in two extents: Split is happening at either end of the extent * c> Splits in three extents: Somone is splitting in middle of the extent * */ static int ext4_split_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_map_blocks *map, int split_flag, int flags) { ext4_lblk_t ee_block; struct ext4_extent *ex; unsigned int ee_len, depth; int err = 0; int uninitialized; int split_flag1, flags1; depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); uninitialized = ext4_ext_is_uninitialized(ex); if (map->m_lblk + map->m_len < ee_block + ee_len) { split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ? EXT4_EXT_MAY_ZEROOUT : 0; flags1 = flags | EXT4_GET_BLOCKS_PRE_IO; if (uninitialized) split_flag1 |= EXT4_EXT_MARK_UNINIT1 | EXT4_EXT_MARK_UNINIT2; err = ext4_split_extent_at(handle, inode, path, map->m_lblk + map->m_len, split_flag1, flags1); if (err) goto out; } ext4_ext_drop_refs(path); path = ext4_ext_find_extent(inode, map->m_lblk, path); if (IS_ERR(path)) return PTR_ERR(path); if (map->m_lblk >= ee_block) { split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ? EXT4_EXT_MAY_ZEROOUT : 0; if (uninitialized) split_flag1 |= EXT4_EXT_MARK_UNINIT1; if (split_flag & EXT4_EXT_MARK_UNINIT2) split_flag1 |= EXT4_EXT_MARK_UNINIT2; err = ext4_split_extent_at(handle, inode, path, map->m_lblk, split_flag1, flags); if (err) goto out; } ext4_ext_show_leaf(inode, path); out: return err ? err : map->m_len; } #define EXT4_EXT_ZERO_LEN 7 /* * This function is called by ext4_ext_map_blocks() if someone tries to write * to an uninitialized extent. It may result in splitting the uninitialized * extent into multiple extents (up to three - one initialized and two * uninitialized). * There are three possibilities: * a> There is no split required: Entire extent should be initialized * b> Splits in two extents: Write is happening at either end of the extent * c> Splits in three extents: Somone is writing in middle of the extent */ static int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path *path) { struct ext4_map_blocks split_map; struct ext4_extent zero_ex; struct ext4_extent *ex; ext4_lblk_t ee_block, eof_block; unsigned int allocated, ee_len, depth; int err = 0; int split_flag = 0; ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical" "block %llu, max_blocks %u\n", inode->i_ino, (unsigned long long)map->m_lblk, map->m_len); eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits; if (eof_block < map->m_lblk + map->m_len) eof_block = map->m_lblk + map->m_len; depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); allocated = ee_len - (map->m_lblk - ee_block); WARN_ON(map->m_lblk < ee_block); /* * It is safe to convert extent to initialized via explicit * zeroout only if extent is fully insde i_size or new_size. */ split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */ if (ee_len <= 2*EXT4_EXT_ZERO_LEN && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { err = ext4_ext_zeroout(inode, ex); if (err) goto out; err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; ext4_ext_mark_initialized(ex); ext4_ext_try_to_merge(inode, path, ex); err = ext4_ext_dirty(handle, inode, path + depth); goto out; } /* * four cases: * 1. split the extent into three extents. * 2. split the extent into two extents, zeroout the first half. * 3. split the extent into two extents, zeroout the second half. * 4. split the extent into two extents with out zeroout. */ split_map.m_lblk = map->m_lblk; split_map.m_len = map->m_len; if (allocated > map->m_len) { if (allocated <= EXT4_EXT_ZERO_LEN && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { /* case 3 */ zero_ex.ee_block = cpu_to_le32(map->m_lblk); zero_ex.ee_len = cpu_to_le16(allocated); ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex) + map->m_lblk - ee_block); err = ext4_ext_zeroout(inode, &zero_ex); if (err) goto out; split_map.m_lblk = map->m_lblk; split_map.m_len = allocated; } else if ((map->m_lblk - ee_block + map->m_len < EXT4_EXT_ZERO_LEN) && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { /* case 2 */ if (map->m_lblk != ee_block) { zero_ex.ee_block = ex->ee_block; zero_ex.ee_len = cpu_to_le16(map->m_lblk - ee_block); ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex)); err = ext4_ext_zeroout(inode, &zero_ex); if (err) goto out; } split_map.m_lblk = ee_block; split_map.m_len = map->m_lblk - ee_block + map->m_len; allocated = map->m_len; } } allocated = ext4_split_extent(handle, inode, path, &split_map, split_flag, 0); if (allocated < 0) err = allocated; out: return err ? err : allocated; } /* * This function is called by ext4_ext_map_blocks() from * ext4_get_blocks_dio_write() when DIO to write * to an uninitialized extent. * * Writing to an uninitialized extent may result in splitting the uninitialized * extent into multiple /initialized uninitialized extents (up to three) * There are three possibilities: * a> There is no split required: Entire extent should be uninitialized * b> Splits in two extents: Write is happening at either end of the extent * c> Splits in three extents: Somone is writing in middle of the extent * * One of more index blocks maybe needed if the extent tree grow after * the uninitialized extent split. To prevent ENOSPC occur at the IO * complete, we need to split the uninitialized extent before DIO submit * the IO. The uninitialized extent called at this time will be split * into three uninitialized extent(at most). After IO complete, the part * being filled will be convert to initialized by the end_io callback function * via ext4_convert_unwritten_extents(). * * Returns the size of uninitialized extent to be written on success. */ static int ext4_split_unwritten_extents(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path *path, int flags) { ext4_lblk_t eof_block; ext4_lblk_t ee_block; struct ext4_extent *ex; unsigned int ee_len; int split_flag = 0, depth; ext_debug("ext4_split_unwritten_extents: inode %lu, logical" "block %llu, max_blocks %u\n", inode->i_ino, (unsigned long long)map->m_lblk, map->m_len); eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits; if (eof_block < map->m_lblk + map->m_len) eof_block = map->m_lblk + map->m_len; /* * It is safe to convert extent to initialized via explicit * zeroout only if extent is fully insde i_size or new_size. */ depth = ext_depth(inode); ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex); split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; split_flag |= EXT4_EXT_MARK_UNINIT2; flags |= EXT4_GET_BLOCKS_PRE_IO; return ext4_split_extent(handle, inode, path, map, split_flag, flags); } static int ext4_convert_unwritten_extents_endio(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { struct ext4_extent *ex; int depth; int err = 0; depth = ext_depth(inode); ex = path[depth].p_ext; ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical" "block %llu, max_blocks %u\n", inode->i_ino, (unsigned long long)le32_to_cpu(ex->ee_block), ext4_ext_get_actual_len(ex)); err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out; /* first mark the extent as initialized */ ext4_ext_mark_initialized(ex); /* note: ext4_ext_correct_indexes() isn't needed here because * borders are not changed */ ext4_ext_try_to_merge(inode, path, ex); /* Mark modified extent as dirty */ err = ext4_ext_dirty(handle, inode, path + depth); out: ext4_ext_show_leaf(inode, path); return err; } static void unmap_underlying_metadata_blocks(struct block_device *bdev, sector_t block, int count) { int i; for (i = 0; i < count; i++) unmap_underlying_metadata(bdev, block + i); } /* * Handle EOFBLOCKS_FL flag, clearing it if necessary */ static int check_eofblocks_fl(handle_t *handle, struct inode *inode, ext4_lblk_t lblk, struct ext4_ext_path *path, unsigned int len) { int i, depth; struct ext4_extent_header *eh; struct ext4_extent *last_ex; if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)) return 0; depth = ext_depth(inode); eh = path[depth].p_hdr; if (unlikely(!eh->eh_entries)) { EXT4_ERROR_INODE(inode, "eh->eh_entries == 0 and " "EOFBLOCKS_FL set"); return -EIO; } last_ex = EXT_LAST_EXTENT(eh); /* * We should clear the EOFBLOCKS_FL flag if we are writing the * last block in the last extent in the file. We test this by * first checking to see if the caller to * ext4_ext_get_blocks() was interested in the last block (or * a block beyond the last block) in the current extent. If * this turns out to be false, we can bail out from this * function immediately. */ if (lblk + len < le32_to_cpu(last_ex->ee_block) + ext4_ext_get_actual_len(last_ex)) return 0; /* * If the caller does appear to be planning to write at or * beyond the end of the current extent, we then test to see * if the current extent is the last extent in the file, by * checking to make sure it was reached via the rightmost node * at each level of the tree. */ for (i = depth-1; i >= 0; i--) if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr)) return 0; ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); return ext4_mark_inode_dirty(handle, inode); } static int ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path *path, int flags, unsigned int allocated, ext4_fsblk_t newblock) { int ret = 0; int err = 0; ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical" "block %llu, max_blocks %u, flags %d, allocated %u", inode->i_ino, (unsigned long long)map->m_lblk, map->m_len, flags, allocated); ext4_ext_show_leaf(inode, path); /* get_block() before submit the IO, split the extent */ if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { ret = ext4_split_unwritten_extents(handle, inode, map, path, flags); /* * Flag the inode(non aio case) or end_io struct (aio case) * that this IO needs to conversion to written when IO is * completed */ if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) { io->flag = EXT4_IO_END_UNWRITTEN; atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); } else ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); if (ext4_should_dioread_nolock(inode)) map->m_flags |= EXT4_MAP_UNINIT; goto out; } /* IO end_io complete, convert the filled extent to written */ if ((flags & EXT4_GET_BLOCKS_CONVERT)) { ret = ext4_convert_unwritten_extents_endio(handle, inode, path); if (ret >= 0) { ext4_update_inode_fsync_trans(handle, inode, 1); err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len); } else err = ret; goto out2; } /* buffered IO case */ /* * repeat fallocate creation request * we already have an unwritten extent */ if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) goto map_out; /* buffered READ or buffered write_begin() lookup */ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { /* * We have blocks reserved already. We * return allocated blocks so that delalloc * won't do block reservation for us. But * the buffer head will be unmapped so that * a read from the block returns 0s. */ map->m_flags |= EXT4_MAP_UNWRITTEN; goto out1; } /* buffered write, writepage time, convert*/ ret = ext4_ext_convert_to_initialized(handle, inode, map, path); if (ret >= 0) { ext4_update_inode_fsync_trans(handle, inode, 1); err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len); if (err < 0) goto out2; } out: if (ret <= 0) { err = ret; goto out2; } else allocated = ret; map->m_flags |= EXT4_MAP_NEW; /* * if we allocated more blocks than requested * we need to make sure we unmap the extra block * allocated. The actual needed block will get * unmapped later when we find the buffer_head marked * new. */ if (allocated > map->m_len) { unmap_underlying_metadata_blocks(inode->i_sb->s_bdev, newblock + map->m_len, allocated - map->m_len); allocated = map->m_len; } /* * If we have done fallocate with the offset that is already * delayed allocated, we would have block reservation * and quota reservation done in the delayed write path. * But fallocate would have already updated quota and block * count for this offset. So cancel these reservation */ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) ext4_da_update_reserve_space(inode, allocated, 0); map_out: map->m_flags |= EXT4_MAP_MAPPED; out1: if (allocated > map->m_len) allocated = map->m_len; ext4_ext_show_leaf(inode, path); map->m_pblk = newblock; map->m_len = allocated; out2: if (path) { ext4_ext_drop_refs(path); kfree(path); } return err ? err : allocated; } /* * Block allocation/map/preallocation routine for extents based files * * * Need to be called with * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) * * return > 0, number of of blocks already mapped/allocated * if create == 0 and these are pre-allocated blocks * buffer head is unmapped * otherwise blocks are mapped * * return = 0, if plain look up failed (blocks have not been allocated) * buffer head is unmapped * * return < 0, error case. */ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, int flags) { struct ext4_ext_path *path = NULL; struct ext4_extent newex, *ex; ext4_fsblk_t newblock = 0; int err = 0, depth, ret; unsigned int allocated = 0; unsigned int punched_out = 0; unsigned int result = 0; struct ext4_allocation_request ar; ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; struct ext4_map_blocks punch_map; ext_debug("blocks %u/%u requested for inode %lu\n", map->m_lblk, map->m_len, inode->i_ino); trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); /* check in cache */ if (!(flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) && ext4_ext_in_cache(inode, map->m_lblk, &newex)) { if (!newex.ee_start_lo && !newex.ee_start_hi) { if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { /* * block isn't allocated yet and * user doesn't want to allocate it */ goto out2; } /* we should allocate requested block */ } else { /* block is already allocated */ newblock = map->m_lblk - le32_to_cpu(newex.ee_block) + ext4_ext_pblock(&newex); /* number of remaining blocks in the extent */ allocated = ext4_ext_get_actual_len(&newex) - (map->m_lblk - le32_to_cpu(newex.ee_block)); goto out; } } /* find extent for this block */ path = ext4_ext_find_extent(inode, map->m_lblk, NULL); if (IS_ERR(path)) { err = PTR_ERR(path); path = NULL; goto out2; } depth = ext_depth(inode); /* * consistent leaf must not be empty; * this situation is possible, though, _during_ tree modification; * this is why assert can't be put in ext4_ext_find_extent() */ if (unlikely(path[depth].p_ext == NULL && depth != 0)) { EXT4_ERROR_INODE(inode, "bad extent address " "lblock: %lu, depth: %d pblock %lld", (unsigned long) map->m_lblk, depth, path[depth].p_block); err = -EIO; goto out2; } ex = path[depth].p_ext; if (ex) { ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); ext4_fsblk_t ee_start = ext4_ext_pblock(ex); unsigned short ee_len; /* * Uninitialized extents are treated as holes, except that * we split out initialized portions during a write. */ ee_len = ext4_ext_get_actual_len(ex); /* if found extent covers block, simply return it */ if (in_range(map->m_lblk, ee_block, ee_len)) { newblock = map->m_lblk - ee_block + ee_start; /* number of remaining blocks in the extent */ allocated = ee_len - (map->m_lblk - ee_block); ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, ee_block, ee_len, newblock); if ((flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0) { /* * Do not put uninitialized extent * in the cache */ if (!ext4_ext_is_uninitialized(ex)) { ext4_ext_put_in_cache(inode, ee_block, ee_len, ee_start); goto out; } ret = ext4_ext_handle_uninitialized_extents( handle, inode, map, path, flags, allocated, newblock); return ret; } /* * Punch out the map length, but only to the * end of the extent */ punched_out = allocated < map->m_len ? allocated : map->m_len; /* * Sense extents need to be converted to * uninitialized, they must fit in an * uninitialized extent */ if (punched_out > EXT_UNINIT_MAX_LEN) punched_out = EXT_UNINIT_MAX_LEN; punch_map.m_lblk = map->m_lblk; punch_map.m_pblk = newblock; punch_map.m_len = punched_out; punch_map.m_flags = 0; /* Check to see if the extent needs to be split */ if (punch_map.m_len != ee_len || punch_map.m_lblk != ee_block) { ret = ext4_split_extent(handle, inode, path, &punch_map, 0, EXT4_GET_BLOCKS_PUNCH_OUT_EXT | EXT4_GET_BLOCKS_PRE_IO); if (ret < 0) { err = ret; goto out2; } /* * find extent for the block at * the start of the hole */ ext4_ext_drop_refs(path); kfree(path); path = ext4_ext_find_extent(inode, map->m_lblk, NULL); if (IS_ERR(path)) { err = PTR_ERR(path); path = NULL; goto out2; } depth = ext_depth(inode); ex = path[depth].p_ext; ee_len = ext4_ext_get_actual_len(ex); ee_block = le32_to_cpu(ex->ee_block); ee_start = ext4_ext_pblock(ex); } ext4_ext_mark_uninitialized(ex); ext4_ext_invalidate_cache(inode); err = ext4_ext_rm_leaf(handle, inode, path, map->m_lblk, map->m_lblk + punched_out); if (!err && path->p_hdr->eh_entries == 0) { /* * Punch hole freed all of this sub tree, * so we need to correct eh_depth */ err = ext4_ext_get_access(handle, inode, path); if (err == 0) { ext_inode_hdr(inode)->eh_depth = 0; ext_inode_hdr(inode)->eh_max = cpu_to_le16(ext4_ext_space_root( inode, 0)); err = ext4_ext_dirty( handle, inode, path); } } goto out2; } } /* * requested block isn't allocated yet; * we couldn't try to create block if create flag is zero */ if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { /* * put just found gap into cache to speed up * subsequent requests */ ext4_ext_put_gap_in_cache(inode, path, map->m_lblk); goto out2; } /* * Okay, we need to do block allocation. */ /* find neighbour allocated blocks */ ar.lleft = map->m_lblk; err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); if (err) goto out2; ar.lright = map->m_lblk; err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright); if (err) goto out2; /* * See if request is beyond maximum number of blocks we can have in * a single extent. For an initialized extent this limit is * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is * EXT_UNINIT_MAX_LEN. */ if (map->m_len > EXT_INIT_MAX_LEN && !(flags & EXT4_GET_BLOCKS_UNINIT_EXT)) map->m_len = EXT_INIT_MAX_LEN; else if (map->m_len > EXT_UNINIT_MAX_LEN && (flags & EXT4_GET_BLOCKS_UNINIT_EXT)) map->m_len = EXT_UNINIT_MAX_LEN; /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ newex.ee_block = cpu_to_le32(map->m_lblk); newex.ee_len = cpu_to_le16(map->m_len); err = ext4_ext_check_overlap(inode, &newex, path); if (err) allocated = ext4_ext_get_actual_len(&newex); else allocated = map->m_len; /* allocate new block */ ar.inode = inode; ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); ar.logical = map->m_lblk; ar.len = allocated; if (S_ISREG(inode->i_mode)) ar.flags = EXT4_MB_HINT_DATA; else /* disable in-core preallocation for non-regular files */ ar.flags = 0; if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE) ar.flags |= EXT4_MB_HINT_NOPREALLOC; newblock = ext4_mb_new_blocks(handle, &ar, &err); if (!newblock) goto out2; ext_debug("allocate new block: goal %llu, found %llu/%u\n", ar.goal, newblock, allocated); /* try to insert new extent into found leaf and return */ ext4_ext_store_pblock(&newex, newblock); newex.ee_len = cpu_to_le16(ar.len); /* Mark uninitialized */ if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){ ext4_ext_mark_uninitialized(&newex); /* * io_end structure was created for every IO write to an * uninitialized extent. To avoid unnecessary conversion, * here we flag the IO that really needs the conversion. * For non asycn direct IO case, flag the inode state * that we need to perform conversion when IO is done. */ if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) { io->flag = EXT4_IO_END_UNWRITTEN; atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); } else ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); } if (ext4_should_dioread_nolock(inode)) map->m_flags |= EXT4_MAP_UNINIT; } err = check_eofblocks_fl(handle, inode, map->m_lblk, path, ar.len); if (!err) err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); if (err) { int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ? EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0; /* free data blocks we just allocated */ /* not a good idea to call discard here directly, * but otherwise we'd need to call it every free() */ ext4_discard_preallocations(inode); ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex), ext4_ext_get_actual_len(&newex), fb_flags); goto out2; } /* previous routine could use block we allocated */ newblock = ext4_ext_pblock(&newex); allocated = ext4_ext_get_actual_len(&newex); if (allocated > map->m_len) allocated = map->m_len; map->m_flags |= EXT4_MAP_NEW; /* * Update reserved blocks/metadata blocks after successful * block allocation which had been deferred till now. */ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) ext4_da_update_reserve_space(inode, allocated, 1); /* * Cache the extent and update transaction to commit on fdatasync only * when it is _not_ an uninitialized extent. */ if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) { ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock); ext4_update_inode_fsync_trans(handle, inode, 1); } else ext4_update_inode_fsync_trans(handle, inode, 0); out: if (allocated > map->m_len) allocated = map->m_len; ext4_ext_show_leaf(inode, path); map->m_flags |= EXT4_MAP_MAPPED; map->m_pblk = newblock; map->m_len = allocated; out2: if (path) { ext4_ext_drop_refs(path); kfree(path); } trace_ext4_ext_map_blocks_exit(inode, map->m_lblk, newblock, map->m_len, err ? err : allocated); result = (flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) ? punched_out : allocated; return err ? err : result; } void ext4_ext_truncate(struct inode *inode) { struct address_space *mapping = inode->i_mapping; struct super_block *sb = inode->i_sb; ext4_lblk_t last_block; handle_t *handle; int err = 0; /* * finish any pending end_io work so we won't run the risk of * converting any truncated blocks to initialized later */ ext4_flush_completed_IO(inode); /* * probably first extent we're gonna free will be last in block */ err = ext4_writepage_trans_blocks(inode); handle = ext4_journal_start(inode, err); if (IS_ERR(handle)) return; if (inode->i_size & (sb->s_blocksize - 1)) ext4_block_truncate_page(handle, mapping, inode->i_size); if (ext4_orphan_add(handle, inode)) goto out_stop; down_write(&EXT4_I(inode)->i_data_sem); ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); /* * TODO: optimization is possible here. * Probably we need not scan at all, * because page truncation is enough. */ /* we have to know where to truncate from in crash case */ EXT4_I(inode)->i_disksize = inode->i_size; ext4_mark_inode_dirty(handle, inode); last_block = (inode->i_size + sb->s_blocksize - 1) >> EXT4_BLOCK_SIZE_BITS(sb); err = ext4_ext_remove_space(inode, last_block); /* In a multi-transaction truncate, we only make the final * transaction synchronous. */ if (IS_SYNC(inode)) ext4_handle_sync(handle); up_write(&EXT4_I(inode)->i_data_sem); out_stop: /* * If this was a simple ftruncate() and the file will remain alive, * then we need to clear up the orphan record which we created above. * However, if this was a real unlink then we were called by * ext4_delete_inode(), and we allow that function to clean up the * orphan info for us. */ if (inode->i_nlink) ext4_orphan_del(handle, inode); inode->i_mtime = inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); } static void ext4_falloc_update_inode(struct inode *inode, int mode, loff_t new_size, int update_ctime) { struct timespec now; if (update_ctime) { now = current_fs_time(inode->i_sb); if (!timespec_equal(&inode->i_ctime, &now)) inode->i_ctime = now; } /* * Update only when preallocation was requested beyond * the file size. */ if (!(mode & FALLOC_FL_KEEP_SIZE)) { if (new_size > i_size_read(inode)) i_size_write(inode, new_size); if (new_size > EXT4_I(inode)->i_disksize) ext4_update_i_disksize(inode, new_size); } else { /* * Mark that we allocate beyond EOF so the subsequent truncate * can proceed even if the new size is the same as i_size. */ if (new_size > i_size_read(inode)) ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); } } /* * preallocate space for a file. This implements ext4's fallocate file * operation, which gets called from sys_fallocate system call. * For block-mapped files, posix_fallocate should fall back to the method * of writing zeroes to the required new blocks (the same behavior which is * expected for file systems which do not support fallocate() system call). */ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file->f_path.dentry->d_inode; handle_t *handle; loff_t new_size; unsigned int max_blocks; int ret = 0; int ret2 = 0; int retries = 0; struct ext4_map_blocks map; unsigned int credits, blkbits = inode->i_blkbits; /* * currently supporting (pre)allocate mode for extent-based * files _only_ */ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) return -EOPNOTSUPP; /* Return error if mode is not supported */ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) return -EOPNOTSUPP; if (mode & FALLOC_FL_PUNCH_HOLE) return ext4_punch_hole(file, offset, len); trace_ext4_fallocate_enter(inode, offset, len, mode); map.m_lblk = offset >> blkbits; /* * We can't just convert len to max_blocks because * If blocksize = 4096 offset = 3072 and len = 2048 */ max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) - map.m_lblk; /* * credits to insert 1 extent into extent tree */ credits = ext4_chunk_trans_blocks(inode, max_blocks); mutex_lock(&inode->i_mutex); ret = inode_newsize_ok(inode, (len + offset)); if (ret) { mutex_unlock(&inode->i_mutex); trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); return ret; } retry: while (ret >= 0 && ret < max_blocks) { map.m_lblk = map.m_lblk + ret; map.m_len = max_blocks = max_blocks - ret; handle = ext4_journal_start(inode, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); break; } ret = ext4_map_blocks(handle, inode, &map, EXT4_GET_BLOCKS_CREATE_UNINIT_EXT | EXT4_GET_BLOCKS_NO_NORMALIZE); if (ret <= 0) { #ifdef EXT4FS_DEBUG WARN_ON(ret <= 0); printk(KERN_ERR "%s: ext4_ext_map_blocks " "returned error inode#%lu, block=%u, " "max_blocks=%u", __func__, inode->i_ino, map.m_lblk, max_blocks); #endif ext4_mark_inode_dirty(handle, inode); ret2 = ext4_journal_stop(handle); break; } if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len, blkbits) >> blkbits)) new_size = offset + len; else new_size = ((loff_t) map.m_lblk + ret) << blkbits; ext4_falloc_update_inode(inode, mode, new_size, (map.m_flags & EXT4_MAP_NEW)); ext4_mark_inode_dirty(handle, inode); ret2 = ext4_journal_stop(handle); if (ret2) break; } if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) { ret = 0; goto retry; } mutex_unlock(&inode->i_mutex); trace_ext4_fallocate_exit(inode, offset, max_blocks, ret > 0 ? ret2 : ret); return ret > 0 ? ret2 : ret; } /* * This function convert a range of blocks to written extents * The caller of this function will pass the start offset and the size. * all unwritten extents within this range will be converted to * written extents. * * This function is called from the direct IO end io call back * function, to convert the fallocated extents after IO is completed. * Returns 0 on success. */ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, ssize_t len) { handle_t *handle; unsigned int max_blocks; int ret = 0; int ret2 = 0; struct ext4_map_blocks map; unsigned int credits, blkbits = inode->i_blkbits; map.m_lblk = offset >> blkbits; /* * We can't just convert len to max_blocks because * If blocksize = 4096 offset = 3072 and len = 2048 */ max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) - map.m_lblk); /* * credits to insert 1 extent into extent tree */ credits = ext4_chunk_trans_blocks(inode, max_blocks); while (ret >= 0 && ret < max_blocks) { map.m_lblk += ret; map.m_len = (max_blocks -= ret); handle = ext4_journal_start(inode, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); break; } ret = ext4_map_blocks(handle, inode, &map, EXT4_GET_BLOCKS_IO_CONVERT_EXT); if (ret <= 0) { WARN_ON(ret <= 0); printk(KERN_ERR "%s: ext4_ext_map_blocks " "returned error inode#%lu, block=%u, " "max_blocks=%u", __func__, inode->i_ino, map.m_lblk, map.m_len); } ext4_mark_inode_dirty(handle, inode); ret2 = ext4_journal_stop(handle); if (ret <= 0 || ret2 ) break; } return ret > 0 ? ret2 : ret; } /* * Callback function called for each extent to gather FIEMAP information. */ static int ext4_ext_fiemap_cb(struct inode *inode, ext4_lblk_t next, struct ext4_ext_cache *newex, struct ext4_extent *ex, void *data) { __u64 logical; __u64 physical; __u64 length; __u32 flags = 0; int ret = 0; struct fiemap_extent_info *fieinfo = data; unsigned char blksize_bits; blksize_bits = inode->i_sb->s_blocksize_bits; logical = (__u64)newex->ec_block << blksize_bits; if (newex->ec_start == 0) { /* * No extent in extent-tree contains block @newex->ec_start, * then the block may stay in 1)a hole or 2)delayed-extent. * * Holes or delayed-extents are processed as follows. * 1. lookup dirty pages with specified range in pagecache. * If no page is got, then there is no delayed-extent and * return with EXT_CONTINUE. * 2. find the 1st mapped buffer, * 3. check if the mapped buffer is both in the request range * and a delayed buffer. If not, there is no delayed-extent, * then return. * 4. a delayed-extent is found, the extent will be collected. */ ext4_lblk_t end = 0; pgoff_t last_offset; pgoff_t offset; pgoff_t index; pgoff_t start_index = 0; struct page **pages = NULL; struct buffer_head *bh = NULL; struct buffer_head *head = NULL; unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *); pages = kmalloc(PAGE_SIZE, GFP_KERNEL); if (pages == NULL) return -ENOMEM; offset = logical >> PAGE_SHIFT; repeat: last_offset = offset; head = NULL; ret = find_get_pages_tag(inode->i_mapping, &offset, PAGECACHE_TAG_DIRTY, nr_pages, pages); if (!(flags & FIEMAP_EXTENT_DELALLOC)) { /* First time, try to find a mapped buffer. */ if (ret == 0) { out: for (index = 0; index < ret; index++) page_cache_release(pages[index]); /* just a hole. */ kfree(pages); return EXT_CONTINUE; } index = 0; next_page: /* Try to find the 1st mapped buffer. */ end = ((__u64)pages[index]->index << PAGE_SHIFT) >> blksize_bits; if (!page_has_buffers(pages[index])) goto out; head = page_buffers(pages[index]); if (!head) goto out; index++; bh = head; do { if (end >= newex->ec_block + newex->ec_len) /* The buffer is out of * the request range. */ goto out; if (buffer_mapped(bh) && end >= newex->ec_block) { start_index = index - 1; /* get the 1st mapped buffer. */ goto found_mapped_buffer; } bh = bh->b_this_page; end++; } while (bh != head); /* No mapped buffer in the range found in this page, * We need to look up next page. */ if (index >= ret) { /* There is no page left, but we need to limit * newex->ec_len. */ newex->ec_len = end - newex->ec_block; goto out; } goto next_page; } else { /*Find contiguous delayed buffers. */ if (ret > 0 && pages[0]->index == last_offset) head = page_buffers(pages[0]); bh = head; index = 1; start_index = 0; } found_mapped_buffer: if (bh != NULL && buffer_delay(bh)) { /* 1st or contiguous delayed buffer found. */ if (!(flags & FIEMAP_EXTENT_DELALLOC)) { /* * 1st delayed buffer found, record * the start of extent. */ flags |= FIEMAP_EXTENT_DELALLOC; newex->ec_block = end; logical = (__u64)end << blksize_bits; } /* Find contiguous delayed buffers. */ do { if (!buffer_delay(bh)) goto found_delayed_extent; bh = bh->b_this_page; end++; } while (bh != head); for (; index < ret; index++) { if (!page_has_buffers(pages[index])) { bh = NULL; break; } head = page_buffers(pages[index]); if (!head) { bh = NULL; break; } if (pages[index]->index != pages[start_index]->index + index - start_index) { /* Blocks are not contiguous. */ bh = NULL; break; } bh = head; do { if (!buffer_delay(bh)) /* Delayed-extent ends. */ goto found_delayed_extent; bh = bh->b_this_page; end++; } while (bh != head); } } else if (!(flags & FIEMAP_EXTENT_DELALLOC)) /* a hole found. */ goto out; found_delayed_extent: newex->ec_len = min(end - newex->ec_block, (ext4_lblk_t)EXT_INIT_MAX_LEN); if (ret == nr_pages && bh != NULL && newex->ec_len < EXT_INIT_MAX_LEN && buffer_delay(bh)) { /* Have not collected an extent and continue. */ for (index = 0; index < ret; index++) page_cache_release(pages[index]); goto repeat; } for (index = 0; index < ret; index++) page_cache_release(pages[index]); kfree(pages); } physical = (__u64)newex->ec_start << blksize_bits; length = (__u64)newex->ec_len << blksize_bits; if (ex && ext4_ext_is_uninitialized(ex)) flags |= FIEMAP_EXTENT_UNWRITTEN; if (next == EXT_MAX_BLOCKS) flags |= FIEMAP_EXTENT_LAST; ret = fiemap_fill_next_extent(fieinfo, logical, physical, length, flags); if (ret < 0) return ret; if (ret == 1) return EXT_BREAK; return EXT_CONTINUE; } /* fiemap flags we can handle specified here */ #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR) static int ext4_xattr_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo) { __u64 physical = 0; __u64 length; __u32 flags = FIEMAP_EXTENT_LAST; int blockbits = inode->i_sb->s_blocksize_bits; int error = 0; /* in-inode? */ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { struct ext4_iloc iloc; int offset; /* offset of xattr in inode */ error = ext4_get_inode_loc(inode, &iloc); if (error) return error; physical = iloc.bh->b_blocknr << blockbits; offset = EXT4_GOOD_OLD_INODE_SIZE + EXT4_I(inode)->i_extra_isize; physical += offset; length = EXT4_SB(inode->i_sb)->s_inode_size - offset; flags |= FIEMAP_EXTENT_DATA_INLINE; brelse(iloc.bh); } else { /* external block */ physical = EXT4_I(inode)->i_file_acl << blockbits; length = inode->i_sb->s_blocksize; } if (physical) error = fiemap_fill_next_extent(fieinfo, 0, physical, length, flags); return (error < 0 ? error : 0); } /* * ext4_ext_punch_hole * * Punches a hole of "length" bytes in a file starting * at byte "offset" * * @inode: The inode of the file to punch a hole in * @offset: The starting byte offset of the hole * @length: The length of the hole * * Returns the number of blocks removed or negative on err */ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) { struct inode *inode = file->f_path.dentry->d_inode; struct super_block *sb = inode->i_sb; struct ext4_ext_cache cache_ex; ext4_lblk_t first_block, last_block, num_blocks, iblock, max_blocks; struct address_space *mapping = inode->i_mapping; struct ext4_map_blocks map; handle_t *handle; loff_t first_block_offset, last_block_offset, block_len; loff_t first_page, last_page, first_page_offset, last_page_offset; int ret, credits, blocks_released, err = 0; first_block = (offset + sb->s_blocksize - 1) >> EXT4_BLOCK_SIZE_BITS(sb); last_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); first_block_offset = first_block << EXT4_BLOCK_SIZE_BITS(sb); last_block_offset = last_block << EXT4_BLOCK_SIZE_BITS(sb); first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; last_page = (offset + length) >> PAGE_CACHE_SHIFT; first_page_offset = first_page << PAGE_CACHE_SHIFT; last_page_offset = last_page << PAGE_CACHE_SHIFT; /* * Write out all dirty pages to avoid race conditions * Then release them. */ if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { err = filemap_write_and_wait_range(mapping, first_page_offset == 0 ? 0 : first_page_offset-1, last_page_offset); if (err) return err; } /* Now release the pages */ if (last_page_offset > first_page_offset) { truncate_inode_pages_range(mapping, first_page_offset, last_page_offset-1); } /* finish any pending end_io work */ ext4_flush_completed_IO(inode); credits = ext4_writepage_trans_blocks(inode); handle = ext4_journal_start(inode, credits); if (IS_ERR(handle)) return PTR_ERR(handle); err = ext4_orphan_add(handle, inode); if (err) goto out; /* * Now we need to zero out the un block aligned data. * If the file is smaller than a block, just * zero out the middle */ if (first_block > last_block) ext4_block_zero_page_range(handle, mapping, offset, length); else { /* zero out the head of the hole before the first block */ block_len = first_block_offset - offset; if (block_len > 0) ext4_block_zero_page_range(handle, mapping, offset, block_len); /* zero out the tail of the hole after the last block */ block_len = offset + length - last_block_offset; if (block_len > 0) { ext4_block_zero_page_range(handle, mapping, last_block_offset, block_len); } } /* If there are no blocks to remove, return now */ if (first_block >= last_block) goto out; down_write(&EXT4_I(inode)->i_data_sem); ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); /* * Loop over all the blocks and identify blocks * that need to be punched out */ iblock = first_block; blocks_released = 0; while (iblock < last_block) { max_blocks = last_block - iblock; num_blocks = 1; memset(&map, 0, sizeof(map)); map.m_lblk = iblock; map.m_len = max_blocks; ret = ext4_ext_map_blocks(handle, inode, &map, EXT4_GET_BLOCKS_PUNCH_OUT_EXT); if (ret > 0) { blocks_released += ret; num_blocks = ret; } else if (ret == 0) { /* * If map blocks could not find the block, * then it is in a hole. If the hole was * not already cached, then map blocks should * put it in the cache. So we can get the hole * out of the cache */ memset(&cache_ex, 0, sizeof(cache_ex)); if ((ext4_ext_check_cache(inode, iblock, &cache_ex)) && !cache_ex.ec_start) { /* The hole is cached */ num_blocks = cache_ex.ec_block + cache_ex.ec_len - iblock; } else { /* The block could not be identified */ err = -EIO; break; } } else { /* Map blocks error */ err = ret; break; } if (num_blocks == 0) { /* This condition should never happen */ ext_debug("Block lookup failed"); err = -EIO; break; } iblock += num_blocks; } if (blocks_released > 0) { ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); } if (IS_SYNC(inode)) ext4_handle_sync(handle); up_write(&EXT4_I(inode)->i_data_sem); out: ext4_orphan_del(handle, inode); inode->i_mtime = inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); return err; } int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len) { ext4_lblk_t start_blk; int error = 0; /* fallback to generic here if not in extents fmt */ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) return generic_block_fiemap(inode, fieinfo, start, len, ext4_get_block); if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) return -EBADR; if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { error = ext4_xattr_fiemap(inode, fieinfo); } else { ext4_lblk_t len_blks; __u64 last_blk; start_blk = start >> inode->i_sb->s_blocksize_bits; last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; if (last_blk >= EXT_MAX_BLOCKS) last_blk = EXT_MAX_BLOCKS-1; len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; /* * Walk the extent tree gathering extent information. * ext4_ext_fiemap_cb will push extents back to user. */ error = ext4_ext_walk_space(inode, start_blk, len_blks, ext4_ext_fiemap_cb, fieinfo); } return error; }