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1// SPDX-License-Identifier: GPL-2.02/*3 *  linux/fs/ext4/ialloc.c4 *5 * Copyright (C) 1992, 1993, 1994, 19956 * Remy Card (card@masi.ibp.fr)7 * Laboratoire MASI - Institut Blaise Pascal8 * Universite Pierre et Marie Curie (Paris VI)9 *10 *  BSD ufs-inspired inode and directory allocation by11 *  Stephen Tweedie (sct@redhat.com), 199312 *  Big-endian to little-endian byte-swapping/bitmaps by13 *        David S. Miller (davem@caip.rutgers.edu), 199514 */15 16#include <linux/time.h>17#include <linux/fs.h>18#include <linux/stat.h>19#include <linux/string.h>20#include <linux/quotaops.h>21#include <linux/buffer_head.h>22#include <linux/random.h>23#include <linux/bitops.h>24#include <linux/blkdev.h>25#include <linux/cred.h>26 27#include <asm/byteorder.h>28 29#include "ext4.h"30#include "ext4_jbd2.h"31#include "xattr.h"32#include "acl.h"33 34#include <trace/events/ext4.h>35 36/*37 * ialloc.c contains the inodes allocation and deallocation routines38 */39 40/*41 * The free inodes are managed by bitmaps.  A file system contains several42 * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap43 * block for inodes, N blocks for the inode table and data blocks.44 *45 * The file system contains group descriptors which are located after the46 * super block.  Each descriptor contains the number of the bitmap block and47 * the free blocks count in the block.48 */49 50/*51 * To avoid calling the atomic setbit hundreds or thousands of times, we only52 * need to use it within a single byte (to ensure we get endianness right).53 * We can use memset for the rest of the bitmap as there are no other users.54 */55void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)56{57	int i;58 59	if (start_bit >= end_bit)60		return;61 62	ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);63	for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)64		ext4_set_bit(i, bitmap);65	if (i < end_bit)66		memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);67}68 69void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)70{71	if (uptodate) {72		set_buffer_uptodate(bh);73		set_bitmap_uptodate(bh);74	}75	unlock_buffer(bh);76	put_bh(bh);77}78 79static int ext4_validate_inode_bitmap(struct super_block *sb,80				      struct ext4_group_desc *desc,81				      ext4_group_t block_group,82				      struct buffer_head *bh)83{84	ext4_fsblk_t	blk;85	struct ext4_group_info *grp;86 87	if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)88		return 0;89 90	if (buffer_verified(bh))91		return 0;92 93	grp = ext4_get_group_info(sb, block_group);94	if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))95		return -EFSCORRUPTED;96 97	ext4_lock_group(sb, block_group);98	if (buffer_verified(bh))99		goto verified;100	blk = ext4_inode_bitmap(sb, desc);101	if (!ext4_inode_bitmap_csum_verify(sb, desc, bh) ||102	    ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) {103		ext4_unlock_group(sb, block_group);104		ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "105			   "inode_bitmap = %llu", block_group, blk);106		ext4_mark_group_bitmap_corrupted(sb, block_group,107					EXT4_GROUP_INFO_IBITMAP_CORRUPT);108		return -EFSBADCRC;109	}110	set_buffer_verified(bh);111verified:112	ext4_unlock_group(sb, block_group);113	return 0;114}115 116/*117 * Read the inode allocation bitmap for a given block_group, reading118 * into the specified slot in the superblock's bitmap cache.119 *120 * Return buffer_head of bitmap on success, or an ERR_PTR on error.121 */122static struct buffer_head *123ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)124{125	struct ext4_group_desc *desc;126	struct ext4_sb_info *sbi = EXT4_SB(sb);127	struct buffer_head *bh = NULL;128	ext4_fsblk_t bitmap_blk;129	int err;130 131	desc = ext4_get_group_desc(sb, block_group, NULL);132	if (!desc)133		return ERR_PTR(-EFSCORRUPTED);134 135	bitmap_blk = ext4_inode_bitmap(sb, desc);136	if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||137	    (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {138		ext4_error(sb, "Invalid inode bitmap blk %llu in "139			   "block_group %u", bitmap_blk, block_group);140		ext4_mark_group_bitmap_corrupted(sb, block_group,141					EXT4_GROUP_INFO_IBITMAP_CORRUPT);142		return ERR_PTR(-EFSCORRUPTED);143	}144	bh = sb_getblk(sb, bitmap_blk);145	if (unlikely(!bh)) {146		ext4_warning(sb, "Cannot read inode bitmap - "147			     "block_group = %u, inode_bitmap = %llu",148			     block_group, bitmap_blk);149		return ERR_PTR(-ENOMEM);150	}151	if (bitmap_uptodate(bh))152		goto verify;153 154	lock_buffer(bh);155	if (bitmap_uptodate(bh)) {156		unlock_buffer(bh);157		goto verify;158	}159 160	ext4_lock_group(sb, block_group);161	if (ext4_has_group_desc_csum(sb) &&162	    (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {163		if (block_group == 0) {164			ext4_unlock_group(sb, block_group);165			unlock_buffer(bh);166			ext4_error(sb, "Inode bitmap for bg 0 marked "167				   "uninitialized");168			err = -EFSCORRUPTED;169			goto out;170		}171		memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);172		ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),173				     sb->s_blocksize * 8, bh->b_data);174		set_bitmap_uptodate(bh);175		set_buffer_uptodate(bh);176		set_buffer_verified(bh);177		ext4_unlock_group(sb, block_group);178		unlock_buffer(bh);179		return bh;180	}181	ext4_unlock_group(sb, block_group);182 183	if (buffer_uptodate(bh)) {184		/*185		 * if not uninit if bh is uptodate,186		 * bitmap is also uptodate187		 */188		set_bitmap_uptodate(bh);189		unlock_buffer(bh);190		goto verify;191	}192	/*193	 * submit the buffer_head for reading194	 */195	trace_ext4_load_inode_bitmap(sb, block_group);196	ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read);197	ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);198	if (!buffer_uptodate(bh)) {199		put_bh(bh);200		ext4_error_err(sb, EIO, "Cannot read inode bitmap - "201			       "block_group = %u, inode_bitmap = %llu",202			       block_group, bitmap_blk);203		ext4_mark_group_bitmap_corrupted(sb, block_group,204				EXT4_GROUP_INFO_IBITMAP_CORRUPT);205		return ERR_PTR(-EIO);206	}207 208verify:209	err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);210	if (err)211		goto out;212	return bh;213out:214	put_bh(bh);215	return ERR_PTR(err);216}217 218/*219 * NOTE! When we get the inode, we're the only people220 * that have access to it, and as such there are no221 * race conditions we have to worry about. The inode222 * is not on the hash-lists, and it cannot be reached223 * through the filesystem because the directory entry224 * has been deleted earlier.225 *226 * HOWEVER: we must make sure that we get no aliases,227 * which means that we have to call "clear_inode()"228 * _before_ we mark the inode not in use in the inode229 * bitmaps. Otherwise a newly created file might use230 * the same inode number (not actually the same pointer231 * though), and then we'd have two inodes sharing the232 * same inode number and space on the harddisk.233 */234void ext4_free_inode(handle_t *handle, struct inode *inode)235{236	struct super_block *sb = inode->i_sb;237	int is_directory;238	unsigned long ino;239	struct buffer_head *bitmap_bh = NULL;240	struct buffer_head *bh2;241	ext4_group_t block_group;242	unsigned long bit;243	struct ext4_group_desc *gdp;244	struct ext4_super_block *es;245	struct ext4_sb_info *sbi;246	int fatal = 0, err, count, cleared;247	struct ext4_group_info *grp;248 249	if (!sb) {250		printk(KERN_ERR "EXT4-fs: %s:%d: inode on "251		       "nonexistent device\n", __func__, __LINE__);252		return;253	}254	if (atomic_read(&inode->i_count) > 1) {255		ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",256			 __func__, __LINE__, inode->i_ino,257			 atomic_read(&inode->i_count));258		return;259	}260	if (inode->i_nlink) {261		ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",262			 __func__, __LINE__, inode->i_ino, inode->i_nlink);263		return;264	}265	sbi = EXT4_SB(sb);266 267	ino = inode->i_ino;268	ext4_debug("freeing inode %lu\n", ino);269	trace_ext4_free_inode(inode);270 271	dquot_initialize(inode);272	dquot_free_inode(inode);273 274	is_directory = S_ISDIR(inode->i_mode);275 276	/* Do this BEFORE marking the inode not in use or returning an error */277	ext4_clear_inode(inode);278 279	es = sbi->s_es;280	if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {281		ext4_error(sb, "reserved or nonexistent inode %lu", ino);282		goto error_return;283	}284	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);285	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);286	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);287	/* Don't bother if the inode bitmap is corrupt. */288	if (IS_ERR(bitmap_bh)) {289		fatal = PTR_ERR(bitmap_bh);290		bitmap_bh = NULL;291		goto error_return;292	}293	if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {294		grp = ext4_get_group_info(sb, block_group);295		if (!grp || unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {296			fatal = -EFSCORRUPTED;297			goto error_return;298		}299	}300 301	BUFFER_TRACE(bitmap_bh, "get_write_access");302	fatal = ext4_journal_get_write_access(handle, sb, bitmap_bh,303					      EXT4_JTR_NONE);304	if (fatal)305		goto error_return;306 307	fatal = -ESRCH;308	gdp = ext4_get_group_desc(sb, block_group, &bh2);309	if (gdp) {310		BUFFER_TRACE(bh2, "get_write_access");311		fatal = ext4_journal_get_write_access(handle, sb, bh2,312						      EXT4_JTR_NONE);313	}314	ext4_lock_group(sb, block_group);315	cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);316	if (fatal || !cleared) {317		ext4_unlock_group(sb, block_group);318		goto out;319	}320 321	count = ext4_free_inodes_count(sb, gdp) + 1;322	ext4_free_inodes_set(sb, gdp, count);323	if (is_directory) {324		count = ext4_used_dirs_count(sb, gdp) - 1;325		ext4_used_dirs_set(sb, gdp, count);326		if (percpu_counter_initialized(&sbi->s_dirs_counter))327			percpu_counter_dec(&sbi->s_dirs_counter);328	}329	ext4_inode_bitmap_csum_set(sb, gdp, bitmap_bh);330	ext4_group_desc_csum_set(sb, block_group, gdp);331	ext4_unlock_group(sb, block_group);332 333	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))334		percpu_counter_inc(&sbi->s_freeinodes_counter);335	if (sbi->s_log_groups_per_flex) {336		struct flex_groups *fg;337 338		fg = sbi_array_rcu_deref(sbi, s_flex_groups,339					 ext4_flex_group(sbi, block_group));340		atomic_inc(&fg->free_inodes);341		if (is_directory)342			atomic_dec(&fg->used_dirs);343	}344	BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");345	fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);346out:347	if (cleared) {348		BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");349		err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);350		if (!fatal)351			fatal = err;352	} else {353		ext4_error(sb, "bit already cleared for inode %lu", ino);354		ext4_mark_group_bitmap_corrupted(sb, block_group,355					EXT4_GROUP_INFO_IBITMAP_CORRUPT);356	}357 358error_return:359	brelse(bitmap_bh);360	ext4_std_error(sb, fatal);361}362 363struct orlov_stats {364	__u64 free_clusters;365	__u32 free_inodes;366	__u32 used_dirs;367};368 369/*370 * Helper function for Orlov's allocator; returns critical information371 * for a particular block group or flex_bg.  If flex_size is 1, then g372 * is a block group number; otherwise it is flex_bg number.373 */374static void get_orlov_stats(struct super_block *sb, ext4_group_t g,375			    int flex_size, struct orlov_stats *stats)376{377	struct ext4_group_desc *desc;378 379	if (flex_size > 1) {380		struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb),381							     s_flex_groups, g);382		stats->free_inodes = atomic_read(&fg->free_inodes);383		stats->free_clusters = atomic64_read(&fg->free_clusters);384		stats->used_dirs = atomic_read(&fg->used_dirs);385		return;386	}387 388	desc = ext4_get_group_desc(sb, g, NULL);389	if (desc) {390		stats->free_inodes = ext4_free_inodes_count(sb, desc);391		stats->free_clusters = ext4_free_group_clusters(sb, desc);392		stats->used_dirs = ext4_used_dirs_count(sb, desc);393	} else {394		stats->free_inodes = 0;395		stats->free_clusters = 0;396		stats->used_dirs = 0;397	}398}399 400/*401 * Orlov's allocator for directories.402 *403 * We always try to spread first-level directories.404 *405 * If there are blockgroups with both free inodes and free clusters counts406 * not worse than average we return one with smallest directory count.407 * Otherwise we simply return a random group.408 *409 * For the rest rules look so:410 *411 * It's OK to put directory into a group unless412 * it has too many directories already (max_dirs) or413 * it has too few free inodes left (min_inodes) or414 * it has too few free clusters left (min_clusters) or415 * Parent's group is preferred, if it doesn't satisfy these416 * conditions we search cyclically through the rest. If none417 * of the groups look good we just look for a group with more418 * free inodes than average (starting at parent's group).419 */420 421static int find_group_orlov(struct super_block *sb, struct inode *parent,422			    ext4_group_t *group, umode_t mode,423			    const struct qstr *qstr)424{425	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;426	struct ext4_sb_info *sbi = EXT4_SB(sb);427	ext4_group_t real_ngroups = ext4_get_groups_count(sb);428	int inodes_per_group = EXT4_INODES_PER_GROUP(sb);429	unsigned int freei, avefreei, grp_free;430	ext4_fsblk_t freec, avefreec;431	unsigned int ndirs;432	int max_dirs, min_inodes;433	ext4_grpblk_t min_clusters;434	ext4_group_t i, grp, g, ngroups;435	struct ext4_group_desc *desc;436	struct orlov_stats stats;437	int flex_size = ext4_flex_bg_size(sbi);438	struct dx_hash_info hinfo;439 440	ngroups = real_ngroups;441	if (flex_size > 1) {442		ngroups = (real_ngroups + flex_size - 1) >>443			sbi->s_log_groups_per_flex;444		parent_group >>= sbi->s_log_groups_per_flex;445	}446 447	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);448	avefreei = freei / ngroups;449	freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);450	avefreec = freec;451	do_div(avefreec, ngroups);452	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);453 454	if (S_ISDIR(mode) &&455	    ((parent == d_inode(sb->s_root)) ||456	     (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {457		int best_ndir = inodes_per_group;458		int ret = -1;459 460		if (qstr) {461			hinfo.hash_version = DX_HASH_HALF_MD4;462			hinfo.seed = sbi->s_hash_seed;463			ext4fs_dirhash(parent, qstr->name, qstr->len, &hinfo);464			parent_group = hinfo.hash % ngroups;465		} else466			parent_group = get_random_u32_below(ngroups);467		for (i = 0; i < ngroups; i++) {468			g = (parent_group + i) % ngroups;469			get_orlov_stats(sb, g, flex_size, &stats);470			if (!stats.free_inodes)471				continue;472			if (stats.used_dirs >= best_ndir)473				continue;474			if (stats.free_inodes < avefreei)475				continue;476			if (stats.free_clusters < avefreec)477				continue;478			grp = g;479			ret = 0;480			best_ndir = stats.used_dirs;481		}482		if (ret)483			goto fallback;484	found_flex_bg:485		if (flex_size == 1) {486			*group = grp;487			return 0;488		}489 490		/*491		 * We pack inodes at the beginning of the flexgroup's492		 * inode tables.  Block allocation decisions will do493		 * something similar, although regular files will494		 * start at 2nd block group of the flexgroup.  See495		 * ext4_ext_find_goal() and ext4_find_near().496		 */497		grp *= flex_size;498		for (i = 0; i < flex_size; i++) {499			if (grp+i >= real_ngroups)500				break;501			desc = ext4_get_group_desc(sb, grp+i, NULL);502			if (desc && ext4_free_inodes_count(sb, desc)) {503				*group = grp+i;504				return 0;505			}506		}507		goto fallback;508	}509 510	max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;511	min_inodes = avefreei - inodes_per_group*flex_size / 4;512	if (min_inodes < 1)513		min_inodes = 1;514	min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;515	if (min_clusters < 0)516		min_clusters = 0;517 518	/*519	 * Start looking in the flex group where we last allocated an520	 * inode for this parent directory521	 */522	if (EXT4_I(parent)->i_last_alloc_group != ~0) {523		parent_group = EXT4_I(parent)->i_last_alloc_group;524		if (flex_size > 1)525			parent_group >>= sbi->s_log_groups_per_flex;526	}527 528	for (i = 0; i < ngroups; i++) {529		grp = (parent_group + i) % ngroups;530		get_orlov_stats(sb, grp, flex_size, &stats);531		if (stats.used_dirs >= max_dirs)532			continue;533		if (stats.free_inodes < min_inodes)534			continue;535		if (stats.free_clusters < min_clusters)536			continue;537		goto found_flex_bg;538	}539 540fallback:541	ngroups = real_ngroups;542	avefreei = freei / ngroups;543fallback_retry:544	parent_group = EXT4_I(parent)->i_block_group;545	for (i = 0; i < ngroups; i++) {546		grp = (parent_group + i) % ngroups;547		desc = ext4_get_group_desc(sb, grp, NULL);548		if (desc) {549			grp_free = ext4_free_inodes_count(sb, desc);550			if (grp_free && grp_free >= avefreei) {551				*group = grp;552				return 0;553			}554		}555	}556 557	if (avefreei) {558		/*559		 * The free-inodes counter is approximate, and for really small560		 * filesystems the above test can fail to find any blockgroups561		 */562		avefreei = 0;563		goto fallback_retry;564	}565 566	return -1;567}568 569static int find_group_other(struct super_block *sb, struct inode *parent,570			    ext4_group_t *group, umode_t mode)571{572	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;573	ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);574	struct ext4_group_desc *desc;575	int flex_size = ext4_flex_bg_size(EXT4_SB(sb));576 577	/*578	 * Try to place the inode is the same flex group as its579	 * parent.  If we can't find space, use the Orlov algorithm to580	 * find another flex group, and store that information in the581	 * parent directory's inode information so that use that flex582	 * group for future allocations.583	 */584	if (flex_size > 1) {585		int retry = 0;586 587	try_again:588		parent_group &= ~(flex_size-1);589		last = parent_group + flex_size;590		if (last > ngroups)591			last = ngroups;592		for  (i = parent_group; i < last; i++) {593			desc = ext4_get_group_desc(sb, i, NULL);594			if (desc && ext4_free_inodes_count(sb, desc)) {595				*group = i;596				return 0;597			}598		}599		if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {600			retry = 1;601			parent_group = EXT4_I(parent)->i_last_alloc_group;602			goto try_again;603		}604		/*605		 * If this didn't work, use the Orlov search algorithm606		 * to find a new flex group; we pass in the mode to607		 * avoid the topdir algorithms.608		 */609		*group = parent_group + flex_size;610		if (*group > ngroups)611			*group = 0;612		return find_group_orlov(sb, parent, group, mode, NULL);613	}614 615	/*616	 * Try to place the inode in its parent directory617	 */618	*group = parent_group;619	desc = ext4_get_group_desc(sb, *group, NULL);620	if (desc && ext4_free_inodes_count(sb, desc) &&621	    ext4_free_group_clusters(sb, desc))622		return 0;623 624	/*625	 * We're going to place this inode in a different blockgroup from its626	 * parent.  We want to cause files in a common directory to all land in627	 * the same blockgroup.  But we want files which are in a different628	 * directory which shares a blockgroup with our parent to land in a629	 * different blockgroup.630	 *631	 * So add our directory's i_ino into the starting point for the hash.632	 */633	*group = (*group + parent->i_ino) % ngroups;634 635	/*636	 * Use a quadratic hash to find a group with a free inode and some free637	 * blocks.638	 */639	for (i = 1; i < ngroups; i <<= 1) {640		*group += i;641		if (*group >= ngroups)642			*group -= ngroups;643		desc = ext4_get_group_desc(sb, *group, NULL);644		if (desc && ext4_free_inodes_count(sb, desc) &&645		    ext4_free_group_clusters(sb, desc))646			return 0;647	}648 649	/*650	 * That failed: try linear search for a free inode, even if that group651	 * has no free blocks.652	 */653	*group = parent_group;654	for (i = 0; i < ngroups; i++) {655		if (++*group >= ngroups)656			*group = 0;657		desc = ext4_get_group_desc(sb, *group, NULL);658		if (desc && ext4_free_inodes_count(sb, desc))659			return 0;660	}661 662	return -1;663}664 665/*666 * In no journal mode, if an inode has recently been deleted, we want667 * to avoid reusing it until we're reasonably sure the inode table668 * block has been written back to disk.  (Yes, these values are669 * somewhat arbitrary...)670 */671#define RECENTCY_MIN	60672#define RECENTCY_DIRTY	300673 674static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)675{676	struct ext4_group_desc	*gdp;677	struct ext4_inode	*raw_inode;678	struct buffer_head	*bh;679	int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;680	int offset, ret = 0;681	int recentcy = RECENTCY_MIN;682	u32 dtime, now;683 684	gdp = ext4_get_group_desc(sb, group, NULL);685	if (unlikely(!gdp))686		return 0;687 688	bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +689		       (ino / inodes_per_block));690	if (!bh || !buffer_uptodate(bh))691		/*692		 * If the block is not in the buffer cache, then it693		 * must have been written out.694		 */695		goto out;696 697	offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);698	raw_inode = (struct ext4_inode *) (bh->b_data + offset);699 700	/* i_dtime is only 32 bits on disk, but we only care about relative701	 * times in the range of a few minutes (i.e. long enough to sync a702	 * recently-deleted inode to disk), so using the low 32 bits of the703	 * clock (a 68 year range) is enough, see time_before32() */704	dtime = le32_to_cpu(raw_inode->i_dtime);705	now = ktime_get_real_seconds();706	if (buffer_dirty(bh))707		recentcy += RECENTCY_DIRTY;708 709	if (dtime && time_before32(dtime, now) &&710	    time_before32(now, dtime + recentcy))711		ret = 1;712out:713	brelse(bh);714	return ret;715}716 717static int find_inode_bit(struct super_block *sb, ext4_group_t group,718			  struct buffer_head *bitmap, unsigned long *ino)719{720	bool check_recently_deleted = EXT4_SB(sb)->s_journal == NULL;721	unsigned long recently_deleted_ino = EXT4_INODES_PER_GROUP(sb);722 723next:724	*ino = ext4_find_next_zero_bit((unsigned long *)725				       bitmap->b_data,726				       EXT4_INODES_PER_GROUP(sb), *ino);727	if (*ino >= EXT4_INODES_PER_GROUP(sb))728		goto not_found;729 730	if (check_recently_deleted && recently_deleted(sb, group, *ino)) {731		recently_deleted_ino = *ino;732		*ino = *ino + 1;733		if (*ino < EXT4_INODES_PER_GROUP(sb))734			goto next;735		goto not_found;736	}737	return 1;738not_found:739	if (recently_deleted_ino >= EXT4_INODES_PER_GROUP(sb))740		return 0;741	/*742	 * Not reusing recently deleted inodes is mostly a preference. We don't743	 * want to report ENOSPC or skew allocation patterns because of that.744	 * So return even recently deleted inode if we could find better in the745	 * given range.746	 */747	*ino = recently_deleted_ino;748	return 1;749}750 751int ext4_mark_inode_used(struct super_block *sb, int ino)752{753	unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);754	struct buffer_head *inode_bitmap_bh = NULL, *group_desc_bh = NULL;755	struct ext4_group_desc *gdp;756	ext4_group_t group;757	int bit;758	int err;759 760	if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)761		return -EFSCORRUPTED;762 763	group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);764	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);765	inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);766	if (IS_ERR(inode_bitmap_bh))767		return PTR_ERR(inode_bitmap_bh);768 769	if (ext4_test_bit(bit, inode_bitmap_bh->b_data)) {770		err = 0;771		goto out;772	}773 774	gdp = ext4_get_group_desc(sb, group, &group_desc_bh);775	if (!gdp) {776		err = -EINVAL;777		goto out;778	}779 780	ext4_set_bit(bit, inode_bitmap_bh->b_data);781 782	BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");783	err = ext4_handle_dirty_metadata(NULL, NULL, inode_bitmap_bh);784	if (err) {785		ext4_std_error(sb, err);786		goto out;787	}788	err = sync_dirty_buffer(inode_bitmap_bh);789	if (err) {790		ext4_std_error(sb, err);791		goto out;792	}793 794	/* We may have to initialize the block bitmap if it isn't already */795	if (ext4_has_group_desc_csum(sb) &&796	    gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {797		struct buffer_head *block_bitmap_bh;798 799		block_bitmap_bh = ext4_read_block_bitmap(sb, group);800		if (IS_ERR(block_bitmap_bh)) {801			err = PTR_ERR(block_bitmap_bh);802			goto out;803		}804 805		BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");806		err = ext4_handle_dirty_metadata(NULL, NULL, block_bitmap_bh);807		sync_dirty_buffer(block_bitmap_bh);808 809		/* recheck and clear flag under lock if we still need to */810		ext4_lock_group(sb, group);811		if (ext4_has_group_desc_csum(sb) &&812		    (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {813			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);814			ext4_free_group_clusters_set(sb, gdp,815				ext4_free_clusters_after_init(sb, group, gdp));816			ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);817			ext4_group_desc_csum_set(sb, group, gdp);818		}819		ext4_unlock_group(sb, group);820		brelse(block_bitmap_bh);821 822		if (err) {823			ext4_std_error(sb, err);824			goto out;825		}826	}827 828	/* Update the relevant bg descriptor fields */829	if (ext4_has_group_desc_csum(sb)) {830		int free;831 832		ext4_lock_group(sb, group); /* while we modify the bg desc */833		free = EXT4_INODES_PER_GROUP(sb) -834			ext4_itable_unused_count(sb, gdp);835		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {836			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);837			free = 0;838		}839 840		/*841		 * Check the relative inode number against the last used842		 * relative inode number in this group. if it is greater843		 * we need to update the bg_itable_unused count844		 */845		if (bit >= free)846			ext4_itable_unused_set(sb, gdp,847					(EXT4_INODES_PER_GROUP(sb) - bit - 1));848	} else {849		ext4_lock_group(sb, group);850	}851 852	ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);853	if (ext4_has_group_desc_csum(sb)) {854		ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);855		ext4_group_desc_csum_set(sb, group, gdp);856	}857 858	ext4_unlock_group(sb, group);859	err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);860	sync_dirty_buffer(group_desc_bh);861out:862	brelse(inode_bitmap_bh);863	return err;864}865 866static int ext4_xattr_credits_for_new_inode(struct inode *dir, mode_t mode,867					    bool encrypt)868{869	struct super_block *sb = dir->i_sb;870	int nblocks = 0;871#ifdef CONFIG_EXT4_FS_POSIX_ACL872	struct posix_acl *p = get_inode_acl(dir, ACL_TYPE_DEFAULT);873 874	if (IS_ERR(p))875		return PTR_ERR(p);876	if (p) {877		int acl_size = p->a_count * sizeof(ext4_acl_entry);878 879		nblocks += (S_ISDIR(mode) ? 2 : 1) *880			__ext4_xattr_set_credits(sb, NULL /* inode */,881						 NULL /* block_bh */, acl_size,882						 true /* is_create */);883		posix_acl_release(p);884	}885#endif886 887#ifdef CONFIG_SECURITY888	{889		int num_security_xattrs = 1;890 891#ifdef CONFIG_INTEGRITY892		num_security_xattrs++;893#endif894		/*895		 * We assume that security xattrs are never more than 1k.896		 * In practice they are under 128 bytes.897		 */898		nblocks += num_security_xattrs *899			__ext4_xattr_set_credits(sb, NULL /* inode */,900						 NULL /* block_bh */, 1024,901						 true /* is_create */);902	}903#endif904	if (encrypt)905		nblocks += __ext4_xattr_set_credits(sb,906						    NULL /* inode */,907						    NULL /* block_bh */,908						    FSCRYPT_SET_CONTEXT_MAX_SIZE,909						    true /* is_create */);910	return nblocks;911}912 913/*914 * There are two policies for allocating an inode.  If the new inode is915 * a directory, then a forward search is made for a block group with both916 * free space and a low directory-to-inode ratio; if that fails, then of917 * the groups with above-average free space, that group with the fewest918 * directories already is chosen.919 *920 * For other inodes, search forward from the parent directory's block921 * group to find a free inode.922 */923struct inode *__ext4_new_inode(struct mnt_idmap *idmap,924			       handle_t *handle, struct inode *dir,925			       umode_t mode, const struct qstr *qstr,926			       __u32 goal, uid_t *owner, __u32 i_flags,927			       int handle_type, unsigned int line_no,928			       int nblocks)929{930	struct super_block *sb;931	struct buffer_head *inode_bitmap_bh = NULL;932	struct buffer_head *group_desc_bh;933	ext4_group_t ngroups, group = 0;934	unsigned long ino = 0;935	struct inode *inode;936	struct ext4_group_desc *gdp = NULL;937	struct ext4_inode_info *ei;938	struct ext4_sb_info *sbi;939	int ret2, err;940	struct inode *ret;941	ext4_group_t i;942	ext4_group_t flex_group;943	struct ext4_group_info *grp = NULL;944	bool encrypt = false;945 946	/* Cannot create files in a deleted directory */947	if (!dir || !dir->i_nlink)948		return ERR_PTR(-EPERM);949 950	sb = dir->i_sb;951	sbi = EXT4_SB(sb);952 953	if (unlikely(ext4_forced_shutdown(sb)))954		return ERR_PTR(-EIO);955 956	ngroups = ext4_get_groups_count(sb);957	trace_ext4_request_inode(dir, mode);958	inode = new_inode(sb);959	if (!inode)960		return ERR_PTR(-ENOMEM);961	ei = EXT4_I(inode);962 963	/*964	 * Initialize owners and quota early so that we don't have to account965	 * for quota initialization worst case in standard inode creating966	 * transaction967	 */968	if (owner) {969		inode->i_mode = mode;970		i_uid_write(inode, owner[0]);971		i_gid_write(inode, owner[1]);972	} else if (test_opt(sb, GRPID)) {973		inode->i_mode = mode;974		inode_fsuid_set(inode, idmap);975		inode->i_gid = dir->i_gid;976	} else977		inode_init_owner(idmap, inode, dir, mode);978 979	if (ext4_has_feature_project(sb) &&980	    ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))981		ei->i_projid = EXT4_I(dir)->i_projid;982	else983		ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);984 985	if (!(i_flags & EXT4_EA_INODE_FL)) {986		err = fscrypt_prepare_new_inode(dir, inode, &encrypt);987		if (err)988			goto out;989	}990 991	err = dquot_initialize(inode);992	if (err)993		goto out;994 995	if (!handle && sbi->s_journal && !(i_flags & EXT4_EA_INODE_FL)) {996		ret2 = ext4_xattr_credits_for_new_inode(dir, mode, encrypt);997		if (ret2 < 0) {998			err = ret2;999			goto out;1000		}1001		nblocks += ret2;1002	}1003 1004	if (!goal)1005		goal = sbi->s_inode_goal;1006 1007	if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) {1008		group = (goal - 1) / EXT4_INODES_PER_GROUP(sb);1009		ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb);1010		ret2 = 0;1011		goto got_group;1012	}1013 1014	if (S_ISDIR(mode))1015		ret2 = find_group_orlov(sb, dir, &group, mode, qstr);1016	else1017		ret2 = find_group_other(sb, dir, &group, mode);1018 1019got_group:1020	EXT4_I(dir)->i_last_alloc_group = group;1021	err = -ENOSPC;1022	if (ret2 == -1)1023		goto out;1024 1025	/*1026	 * Normally we will only go through one pass of this loop,1027	 * unless we get unlucky and it turns out the group we selected1028	 * had its last inode grabbed by someone else.1029	 */1030	for (i = 0; i < ngroups; i++, ino = 0) {1031		err = -EIO;1032 1033		gdp = ext4_get_group_desc(sb, group, &group_desc_bh);1034		if (!gdp)1035			goto out;1036 1037		/*1038		 * Check free inodes count before loading bitmap.1039		 */1040		if (ext4_free_inodes_count(sb, gdp) == 0)1041			goto next_group;1042 1043		if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {1044			grp = ext4_get_group_info(sb, group);1045			/*1046			 * Skip groups with already-known suspicious inode1047			 * tables1048			 */1049			if (!grp || EXT4_MB_GRP_IBITMAP_CORRUPT(grp))1050				goto next_group;1051		}1052 1053		brelse(inode_bitmap_bh);1054		inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);1055		/* Skip groups with suspicious inode tables */1056		if (IS_ERR(inode_bitmap_bh)) {1057			inode_bitmap_bh = NULL;1058			goto next_group;1059		}1060		if (!(sbi->s_mount_state & EXT4_FC_REPLAY) &&1061		    EXT4_MB_GRP_IBITMAP_CORRUPT(grp))1062			goto next_group;1063 1064		ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);1065		if (!ret2)1066			goto next_group;1067 1068		if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {1069			ext4_error(sb, "reserved inode found cleared - "1070				   "inode=%lu", ino + 1);1071			ext4_mark_group_bitmap_corrupted(sb, group,1072					EXT4_GROUP_INFO_IBITMAP_CORRUPT);1073			goto next_group;1074		}1075 1076		if ((!(sbi->s_mount_state & EXT4_FC_REPLAY)) && !handle) {1077			BUG_ON(nblocks <= 0);1078			handle = __ext4_journal_start_sb(NULL, dir->i_sb,1079				 line_no, handle_type, nblocks, 0,1080				 ext4_trans_default_revoke_credits(sb));1081			if (IS_ERR(handle)) {1082				err = PTR_ERR(handle);1083				ext4_std_error(sb, err);1084				goto out;1085			}1086		}1087		BUFFER_TRACE(inode_bitmap_bh, "get_write_access");1088		err = ext4_journal_get_write_access(handle, sb, inode_bitmap_bh,1089						    EXT4_JTR_NONE);1090		if (err) {1091			ext4_std_error(sb, err);1092			goto out;1093		}1094		ext4_lock_group(sb, group);1095		ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);1096		if (ret2) {1097			/* Someone already took the bit. Repeat the search1098			 * with lock held.1099			 */1100			ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);1101			if (ret2) {1102				ext4_set_bit(ino, inode_bitmap_bh->b_data);1103				ret2 = 0;1104			} else {1105				ret2 = 1; /* we didn't grab the inode */1106			}1107		}1108		ext4_unlock_group(sb, group);1109		ino++;		/* the inode bitmap is zero-based */1110		if (!ret2)1111			goto got; /* we grabbed the inode! */1112 1113next_group:1114		if (++group == ngroups)1115			group = 0;1116	}1117	err = -ENOSPC;1118	goto out;1119 1120got:1121	BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");1122	err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);1123	if (err) {1124		ext4_std_error(sb, err);1125		goto out;1126	}1127 1128	BUFFER_TRACE(group_desc_bh, "get_write_access");1129	err = ext4_journal_get_write_access(handle, sb, group_desc_bh,1130					    EXT4_JTR_NONE);1131	if (err) {1132		ext4_std_error(sb, err);1133		goto out;1134	}1135 1136	/* We may have to initialize the block bitmap if it isn't already */1137	if (ext4_has_group_desc_csum(sb) &&1138	    gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {1139		struct buffer_head *block_bitmap_bh;1140 1141		block_bitmap_bh = ext4_read_block_bitmap(sb, group);1142		if (IS_ERR(block_bitmap_bh)) {1143			err = PTR_ERR(block_bitmap_bh);1144			goto out;1145		}1146		BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");1147		err = ext4_journal_get_write_access(handle, sb, block_bitmap_bh,1148						    EXT4_JTR_NONE);1149		if (err) {1150			brelse(block_bitmap_bh);1151			ext4_std_error(sb, err);1152			goto out;1153		}1154 1155		BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");1156		err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh);1157 1158		/* recheck and clear flag under lock if we still need to */1159		ext4_lock_group(sb, group);1160		if (ext4_has_group_desc_csum(sb) &&1161		    (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {1162			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);1163			ext4_free_group_clusters_set(sb, gdp,1164				ext4_free_clusters_after_init(sb, group, gdp));1165			ext4_block_bitmap_csum_set(sb, gdp, block_bitmap_bh);1166			ext4_group_desc_csum_set(sb, group, gdp);1167		}1168		ext4_unlock_group(sb, group);1169		brelse(block_bitmap_bh);1170 1171		if (err) {1172			ext4_std_error(sb, err);1173			goto out;1174		}1175	}1176 1177	/* Update the relevant bg descriptor fields */1178	if (ext4_has_group_desc_csum(sb)) {1179		int free;1180		struct ext4_group_info *grp = NULL;1181 1182		if (!(sbi->s_mount_state & EXT4_FC_REPLAY)) {1183			grp = ext4_get_group_info(sb, group);1184			if (!grp) {1185				err = -EFSCORRUPTED;1186				goto out;1187			}1188			down_read(&grp->alloc_sem); /*1189						     * protect vs itable1190						     * lazyinit1191						     */1192		}1193		ext4_lock_group(sb, group); /* while we modify the bg desc */1194		free = EXT4_INODES_PER_GROUP(sb) -1195			ext4_itable_unused_count(sb, gdp);1196		if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {1197			gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);1198			free = 0;1199		}1200		/*1201		 * Check the relative inode number against the last used1202		 * relative inode number in this group. if it is greater1203		 * we need to update the bg_itable_unused count1204		 */1205		if (ino > free)1206			ext4_itable_unused_set(sb, gdp,1207					(EXT4_INODES_PER_GROUP(sb) - ino));1208		if (!(sbi->s_mount_state & EXT4_FC_REPLAY))1209			up_read(&grp->alloc_sem);1210	} else {1211		ext4_lock_group(sb, group);1212	}1213 1214	ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);1215	if (S_ISDIR(mode)) {1216		ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);1217		if (sbi->s_log_groups_per_flex) {1218			ext4_group_t f = ext4_flex_group(sbi, group);1219 1220			atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups,1221							f)->used_dirs);1222		}1223	}1224	if (ext4_has_group_desc_csum(sb)) {1225		ext4_inode_bitmap_csum_set(sb, gdp, inode_bitmap_bh);1226		ext4_group_desc_csum_set(sb, group, gdp);1227	}1228	ext4_unlock_group(sb, group);1229 1230	BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");1231	err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);1232	if (err) {1233		ext4_std_error(sb, err);1234		goto out;1235	}1236 1237	percpu_counter_dec(&sbi->s_freeinodes_counter);1238	if (S_ISDIR(mode))1239		percpu_counter_inc(&sbi->s_dirs_counter);1240 1241	if (sbi->s_log_groups_per_flex) {1242		flex_group = ext4_flex_group(sbi, group);1243		atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups,1244						flex_group)->free_inodes);1245	}1246 1247	inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);1248	/* This is the optimal IO size (for stat), not the fs block size */1249	inode->i_blocks = 0;1250	simple_inode_init_ts(inode);1251	ei->i_crtime = inode_get_mtime(inode);1252 1253	memset(ei->i_data, 0, sizeof(ei->i_data));1254	ei->i_dir_start_lookup = 0;1255	ei->i_disksize = 0;1256 1257	/* Don't inherit extent flag from directory, amongst others. */1258	ei->i_flags =1259		ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);1260	ei->i_flags |= i_flags;1261	ei->i_file_acl = 0;1262	ei->i_dtime = 0;1263	ei->i_block_group = group;1264	ei->i_last_alloc_group = ~0;1265 1266	ext4_set_inode_flags(inode, true);1267	if (IS_DIRSYNC(inode))1268		ext4_handle_sync(handle);1269	if (insert_inode_locked(inode) < 0) {1270		/*1271		 * Likely a bitmap corruption causing inode to be allocated1272		 * twice.1273		 */1274		err = -EIO;1275		ext4_error(sb, "failed to insert inode %lu: doubly allocated?",1276			   inode->i_ino);1277		ext4_mark_group_bitmap_corrupted(sb, group,1278					EXT4_GROUP_INFO_IBITMAP_CORRUPT);1279		goto out;1280	}1281	inode->i_generation = get_random_u32();1282 1283	/* Precompute checksum seed for inode metadata */1284	if (ext4_has_metadata_csum(sb)) {1285		__u32 csum;1286		__le32 inum = cpu_to_le32(inode->i_ino);1287		__le32 gen = cpu_to_le32(inode->i_generation);1288		csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,1289				   sizeof(inum));1290		ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,1291					      sizeof(gen));1292	}1293 1294	ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */1295	ext4_set_inode_state(inode, EXT4_STATE_NEW);1296 1297	ei->i_extra_isize = sbi->s_want_extra_isize;1298	ei->i_inline_off = 0;1299	if (ext4_has_feature_inline_data(sb) &&1300	    (!(ei->i_flags & EXT4_DAX_FL) || S_ISDIR(mode)))1301		ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);1302	ret = inode;1303	err = dquot_alloc_inode(inode);1304	if (err)1305		goto fail_drop;1306 1307	/*1308	 * Since the encryption xattr will always be unique, create it first so1309	 * that it's less likely to end up in an external xattr block and1310	 * prevent its deduplication.1311	 */1312	if (encrypt) {1313		err = fscrypt_set_context(inode, handle);1314		if (err)1315			goto fail_free_drop;1316	}1317 1318	if (!(ei->i_flags & EXT4_EA_INODE_FL)) {1319		err = ext4_init_acl(handle, inode, dir);1320		if (err)1321			goto fail_free_drop;1322 1323		err = ext4_init_security(handle, inode, dir, qstr);1324		if (err)1325			goto fail_free_drop;1326	}1327 1328	if (ext4_has_feature_extents(sb)) {1329		/* set extent flag only for directory, file and normal symlink*/1330		if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {1331			ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS);1332			ext4_ext_tree_init(handle, inode);1333		}1334	}1335 1336	ext4_update_inode_fsync_trans(handle, inode, 1);1337 1338	err = ext4_mark_inode_dirty(handle, inode);1339	if (err) {1340		ext4_std_error(sb, err);1341		goto fail_free_drop;1342	}1343 1344	ext4_debug("allocating inode %lu\n", inode->i_ino);1345	trace_ext4_allocate_inode(inode, dir, mode);1346	brelse(inode_bitmap_bh);1347	return ret;1348 1349fail_free_drop:1350	dquot_free_inode(inode);1351fail_drop:1352	clear_nlink(inode);1353	unlock_new_inode(inode);1354out:1355	dquot_drop(inode);1356	inode->i_flags |= S_NOQUOTA;1357	iput(inode);1358	brelse(inode_bitmap_bh);1359	return ERR_PTR(err);1360}1361 1362/* Verify that we are loading a valid orphan from disk */1363struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)1364{1365	unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);1366	ext4_group_t block_group;1367	int bit;1368	struct buffer_head *bitmap_bh = NULL;1369	struct inode *inode = NULL;1370	int err = -EFSCORRUPTED;1371 1372	if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)1373		goto bad_orphan;1374 1375	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);1376	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);1377	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);1378	if (IS_ERR(bitmap_bh))1379		return ERR_CAST(bitmap_bh);1380 1381	/* Having the inode bit set should be a 100% indicator that this1382	 * is a valid orphan (no e2fsck run on fs).  Orphans also include1383	 * inodes that were being truncated, so we can't check i_nlink==0.1384	 */1385	if (!ext4_test_bit(bit, bitmap_bh->b_data))1386		goto bad_orphan;1387 1388	inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);1389	if (IS_ERR(inode)) {1390		err = PTR_ERR(inode);1391		ext4_error_err(sb, -err,1392			       "couldn't read orphan inode %lu (err %d)",1393			       ino, err);1394		brelse(bitmap_bh);1395		return inode;1396	}1397 1398	/*1399	 * If the orphans has i_nlinks > 0 then it should be able to1400	 * be truncated, otherwise it won't be removed from the orphan1401	 * list during processing and an infinite loop will result.1402	 * Similarly, it must not be a bad inode.1403	 */1404	if ((inode->i_nlink && !ext4_can_truncate(inode)) ||1405	    is_bad_inode(inode))1406		goto bad_orphan;1407 1408	if (NEXT_ORPHAN(inode) > max_ino)1409		goto bad_orphan;1410	brelse(bitmap_bh);1411	return inode;1412 1413bad_orphan:1414	ext4_error(sb, "bad orphan inode %lu", ino);1415	if (bitmap_bh)1416		printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n",1417		       bit, (unsigned long long)bitmap_bh->b_blocknr,1418		       ext4_test_bit(bit, bitmap_bh->b_data));1419	if (inode) {1420		printk(KERN_ERR "is_bad_inode(inode)=%d\n",1421		       is_bad_inode(inode));1422		printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n",1423		       NEXT_ORPHAN(inode));1424		printk(KERN_ERR "max_ino=%lu\n", max_ino);1425		printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink);1426		/* Avoid freeing blocks if we got a bad deleted inode */1427		if (inode->i_nlink == 0)1428			inode->i_blocks = 0;1429		iput(inode);1430	}1431	brelse(bitmap_bh);1432	return ERR_PTR(err);1433}1434 1435unsigned long ext4_count_free_inodes(struct super_block *sb)1436{1437	unsigned long desc_count;1438	struct ext4_group_desc *gdp;1439	ext4_group_t i, ngroups = ext4_get_groups_count(sb);1440#ifdef EXT4FS_DEBUG1441	struct ext4_super_block *es;1442	unsigned long bitmap_count, x;1443	struct buffer_head *bitmap_bh = NULL;1444 1445	es = EXT4_SB(sb)->s_es;1446	desc_count = 0;1447	bitmap_count = 0;1448	gdp = NULL;1449	for (i = 0; i < ngroups; i++) {1450		gdp = ext4_get_group_desc(sb, i, NULL);1451		if (!gdp)1452			continue;1453		desc_count += ext4_free_inodes_count(sb, gdp);1454		brelse(bitmap_bh);1455		bitmap_bh = ext4_read_inode_bitmap(sb, i);1456		if (IS_ERR(bitmap_bh)) {1457			bitmap_bh = NULL;1458			continue;1459		}1460 1461		x = ext4_count_free(bitmap_bh->b_data,1462				    EXT4_INODES_PER_GROUP(sb) / 8);1463		printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",1464			(unsigned long) i, ext4_free_inodes_count(sb, gdp), x);1465		bitmap_count += x;1466	}1467	brelse(bitmap_bh);1468	printk(KERN_DEBUG "ext4_count_free_inodes: "1469	       "stored = %u, computed = %lu, %lu\n",1470	       le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);1471	return desc_count;1472#else1473	desc_count = 0;1474	for (i = 0; i < ngroups; i++) {1475		gdp = ext4_get_group_desc(sb, i, NULL);1476		if (!gdp)1477			continue;1478		desc_count += ext4_free_inodes_count(sb, gdp);1479		cond_resched();1480	}1481	return desc_count;1482#endif1483}1484 1485/* Called at mount-time, super-block is locked */1486unsigned long ext4_count_dirs(struct super_block * sb)1487{1488	unsigned long count = 0;1489	ext4_group_t i, ngroups = ext4_get_groups_count(sb);1490 1491	for (i = 0; i < ngroups; i++) {1492		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);1493		if (!gdp)1494			continue;1495		count += ext4_used_dirs_count(sb, gdp);1496	}1497	return count;1498}1499 1500/*1501 * Zeroes not yet zeroed inode table - just write zeroes through the whole1502 * inode table. Must be called without any spinlock held. The only place1503 * where it is called from on active part of filesystem is ext4lazyinit1504 * thread, so we do not need any special locks, however we have to prevent1505 * inode allocation from the current group, so we take alloc_sem lock, to1506 * block ext4_new_inode() until we are finished.1507 */1508int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,1509				 int barrier)1510{1511	struct ext4_group_info *grp = ext4_get_group_info(sb, group);1512	struct ext4_sb_info *sbi = EXT4_SB(sb);1513	struct ext4_group_desc *gdp = NULL;1514	struct buffer_head *group_desc_bh;1515	handle_t *handle;1516	ext4_fsblk_t blk;1517	int num, ret = 0, used_blks = 0;1518	unsigned long used_inos = 0;1519 1520	gdp = ext4_get_group_desc(sb, group, &group_desc_bh);1521	if (!gdp || !grp)1522		goto out;1523 1524	/*1525	 * We do not need to lock this, because we are the only one1526	 * handling this flag.1527	 */1528	if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))1529		goto out;1530 1531	handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);1532	if (IS_ERR(handle)) {1533		ret = PTR_ERR(handle);1534		goto out;1535	}1536 1537	down_write(&grp->alloc_sem);1538	/*1539	 * If inode bitmap was already initialized there may be some1540	 * used inodes so we need to skip blocks with used inodes in1541	 * inode table.1542	 */1543	if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) {1544		used_inos = EXT4_INODES_PER_GROUP(sb) -1545			    ext4_itable_unused_count(sb, gdp);1546		used_blks = DIV_ROUND_UP(used_inos, sbi->s_inodes_per_block);1547 1548		/* Bogus inode unused count? */1549		if (used_blks < 0 || used_blks > sbi->s_itb_per_group) {1550			ext4_error(sb, "Something is wrong with group %u: "1551				   "used itable blocks: %d; "1552				   "itable unused count: %u",1553				   group, used_blks,1554				   ext4_itable_unused_count(sb, gdp));1555			ret = 1;1556			goto err_out;1557		}1558 1559		used_inos += group * EXT4_INODES_PER_GROUP(sb);1560		/*1561		 * Are there some uninitialized inodes in the inode table1562		 * before the first normal inode?1563		 */1564		if ((used_blks != sbi->s_itb_per_group) &&1565		     (used_inos < EXT4_FIRST_INO(sb))) {1566			ext4_error(sb, "Something is wrong with group %u: "1567				   "itable unused count: %u; "1568				   "itables initialized count: %ld",1569				   group, ext4_itable_unused_count(sb, gdp),1570				   used_inos);1571			ret = 1;1572			goto err_out;1573		}1574	}1575 1576	blk = ext4_inode_table(sb, gdp) + used_blks;1577	num = sbi->s_itb_per_group - used_blks;1578 1579	BUFFER_TRACE(group_desc_bh, "get_write_access");1580	ret = ext4_journal_get_write_access(handle, sb, group_desc_bh,1581					    EXT4_JTR_NONE);1582	if (ret)1583		goto err_out;1584 1585	/*1586	 * Skip zeroout if the inode table is full. But we set the ZEROED1587	 * flag anyway, because obviously, when it is full it does not need1588	 * further zeroing.1589	 */1590	if (unlikely(num == 0))1591		goto skip_zeroout;1592 1593	ext4_debug("going to zero out inode table in group %d\n",1594		   group);1595	ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS);1596	if (ret < 0)1597		goto err_out;1598	if (barrier)1599		blkdev_issue_flush(sb->s_bdev);1600 1601skip_zeroout:1602	ext4_lock_group(sb, group);1603	gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);1604	ext4_group_desc_csum_set(sb, group, gdp);1605	ext4_unlock_group(sb, group);1606 1607	BUFFER_TRACE(group_desc_bh,1608		     "call ext4_handle_dirty_metadata");1609	ret = ext4_handle_dirty_metadata(handle, NULL,1610					 group_desc_bh);1611 1612err_out:1613	up_write(&grp->alloc_sem);1614	ext4_journal_stop(handle);1615out:1616	return ret;1617}1618