// SPDX-License-Identifier: GPL-2.0 /* * fs/ext4/fast_commit.c * * Written by Harshad Shirwadkar * * Ext4 fast commits routines. */ #include "ext4.h" #include "ext4_jbd2.h" #include "ext4_extents.h" #include "mballoc.h" /* * Ext4 Fast Commits * ----------------- * * Ext4 fast commits implement fine grained journalling for Ext4. * * Fast commits are organized as a log of tag-length-value (TLV) structs. (See * struct ext4_fc_tl). Each TLV contains some delta that is replayed TLV by * TLV during the recovery phase. For the scenarios for which we currently * don't have replay code, fast commit falls back to full commits. * Fast commits record delta in one of the following three categories. * * (A) Directory entry updates: * * - EXT4_FC_TAG_UNLINK - records directory entry unlink * - EXT4_FC_TAG_LINK - records directory entry link * - EXT4_FC_TAG_CREAT - records inode and directory entry creation * * (B) File specific data range updates: * * - EXT4_FC_TAG_ADD_RANGE - records addition of new blocks to an inode * - EXT4_FC_TAG_DEL_RANGE - records deletion of blocks from an inode * * (C) Inode metadata (mtime / ctime etc): * * - EXT4_FC_TAG_INODE - record the inode that should be replayed * during recovery. Note that iblocks field is * not replayed and instead derived during * replay. * Commit Operation * ---------------- * With fast commits, we maintain all the directory entry operations in the * order in which they are issued in an in-memory queue. This queue is flushed * to disk during the commit operation. We also maintain a list of inodes * that need to be committed during a fast commit in another in memory queue of * inodes. During the commit operation, we commit in the following order: * * [1] Lock inodes for any further data updates by setting COMMITTING state * [2] Submit data buffers of all the inodes * [3] Wait for [2] to complete * [4] Commit all the directory entry updates in the fast commit space * [5] Commit all the changed inode structures * [6] Write tail tag (this tag ensures the atomicity, please read the following * section for more details). * [7] Wait for [4], [5] and [6] to complete. * * All the inode updates must call ext4_fc_start_update() before starting an * update. If such an ongoing update is present, fast commit waits for it to * complete. The completion of such an update is marked by * ext4_fc_stop_update(). * * Fast Commit Ineligibility * ------------------------- * Not all operations are supported by fast commits today (e.g extended * attributes). Fast commit ineligiblity is marked by calling one of the * two following functions: * * - ext4_fc_mark_ineligible(): This makes next fast commit operation to fall * back to full commit. This is useful in case of transient errors. * * - ext4_fc_start_ineligible() and ext4_fc_stop_ineligible() - This makes all * the fast commits happening between ext4_fc_start_ineligible() and * ext4_fc_stop_ineligible() and one fast commit after the call to * ext4_fc_stop_ineligible() to fall back to full commits. It is important to * make one more fast commit to fall back to full commit after stop call so * that it guaranteed that the fast commit ineligible operation contained * within ext4_fc_start_ineligible() and ext4_fc_stop_ineligible() is * followed by at least 1 full commit. * * Atomicity of commits * -------------------- * In order to gaurantee atomicity during the commit operation, fast commit * uses "EXT4_FC_TAG_TAIL" tag that marks a fast commit as complete. Tail * tag contains CRC of the contents and TID of the transaction after which * this fast commit should be applied. Recovery code replays fast commit * logs only if there's at least 1 valid tail present. For every fast commit * operation, there is 1 tail. This means, we may end up with multiple tails * in the fast commit space. Here's an example: * * - Create a new file A and remove existing file B * - fsync() * - Append contents to file A * - Truncate file A * - fsync() * * The fast commit space at the end of above operations would look like this: * [HEAD] [CREAT A] [UNLINK B] [TAIL] [ADD_RANGE A] [DEL_RANGE A] [TAIL] * |<--- Fast Commit 1 --->|<--- Fast Commit 2 ---->| * * Replay code should thus check for all the valid tails in the FC area. * * TODOs * ----- * 1) Make fast commit atomic updates more fine grained. Today, a fast commit * eligible update must be protected within ext4_fc_start_update() and * ext4_fc_stop_update(). These routines are called at much higher * routines. This can be made more fine grained by combining with * ext4_journal_start(). * * 2) Same above for ext4_fc_start_ineligible() and ext4_fc_stop_ineligible() * * 3) Handle more ineligible cases. */ #include static struct kmem_cache *ext4_fc_dentry_cachep; static void ext4_end_buffer_io_sync(struct buffer_head *bh, int uptodate) { BUFFER_TRACE(bh, ""); if (uptodate) { ext4_debug("%s: Block %lld up-to-date", __func__, bh->b_blocknr); set_buffer_uptodate(bh); } else { ext4_debug("%s: Block %lld not up-to-date", __func__, bh->b_blocknr); clear_buffer_uptodate(bh); } unlock_buffer(bh); } static inline void ext4_fc_reset_inode(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); ei->i_fc_lblk_start = 0; ei->i_fc_lblk_len = 0; } void ext4_fc_init_inode(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); ext4_fc_reset_inode(inode); ext4_clear_inode_state(inode, EXT4_STATE_FC_COMMITTING); INIT_LIST_HEAD(&ei->i_fc_list); init_waitqueue_head(&ei->i_fc_wait); atomic_set(&ei->i_fc_updates, 0); ei->i_fc_committed_subtid = 0; } /* * Inform Ext4's fast about start of an inode update * * This function is called by the high level call VFS callbacks before * performing any inode update. This function blocks if there's an ongoing * fast commit on the inode in question. */ void ext4_fc_start_update(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT)) return; restart: spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock); if (list_empty(&ei->i_fc_list)) goto out; if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) { wait_queue_head_t *wq; #if (BITS_PER_LONG < 64) DEFINE_WAIT_BIT(wait, &ei->i_state_flags, EXT4_STATE_FC_COMMITTING); wq = bit_waitqueue(&ei->i_state_flags, EXT4_STATE_FC_COMMITTING); #else DEFINE_WAIT_BIT(wait, &ei->i_flags, EXT4_STATE_FC_COMMITTING); wq = bit_waitqueue(&ei->i_flags, EXT4_STATE_FC_COMMITTING); #endif prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); schedule(); finish_wait(wq, &wait.wq_entry); goto restart; } out: atomic_inc(&ei->i_fc_updates); spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); } /* * Stop inode update and wake up waiting fast commits if any. */ void ext4_fc_stop_update(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT)) return; if (atomic_dec_and_test(&ei->i_fc_updates)) wake_up_all(&ei->i_fc_wait); } /* * Remove inode from fast commit list. If the inode is being committed * we wait until inode commit is done. */ void ext4_fc_del(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT)) return; if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT)) return; restart: spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock); if (list_empty(&ei->i_fc_list)) { spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); return; } if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) { wait_queue_head_t *wq; #if (BITS_PER_LONG < 64) DEFINE_WAIT_BIT(wait, &ei->i_state_flags, EXT4_STATE_FC_COMMITTING); wq = bit_waitqueue(&ei->i_state_flags, EXT4_STATE_FC_COMMITTING); #else DEFINE_WAIT_BIT(wait, &ei->i_flags, EXT4_STATE_FC_COMMITTING); wq = bit_waitqueue(&ei->i_flags, EXT4_STATE_FC_COMMITTING); #endif prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); schedule(); finish_wait(wq, &wait.wq_entry); goto restart; } if (!list_empty(&ei->i_fc_list)) list_del_init(&ei->i_fc_list); spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); } /* * Mark file system as fast commit ineligible. This means that next commit * operation would result in a full jbd2 commit. */ void ext4_fc_mark_ineligible(struct super_block *sb, int reason) { struct ext4_sb_info *sbi = EXT4_SB(sb); sbi->s_mount_state |= EXT4_FC_INELIGIBLE; WARN_ON(reason >= EXT4_FC_REASON_MAX); sbi->s_fc_stats.fc_ineligible_reason_count[reason]++; } /* * Start a fast commit ineligible update. Any commits that happen while * such an operation is in progress fall back to full commits. */ void ext4_fc_start_ineligible(struct super_block *sb, int reason) { struct ext4_sb_info *sbi = EXT4_SB(sb); WARN_ON(reason >= EXT4_FC_REASON_MAX); sbi->s_fc_stats.fc_ineligible_reason_count[reason]++; atomic_inc(&sbi->s_fc_ineligible_updates); } /* * Stop a fast commit ineligible update. We set EXT4_FC_INELIGIBLE flag here * to ensure that after stopping the ineligible update, at least one full * commit takes place. */ void ext4_fc_stop_ineligible(struct super_block *sb) { EXT4_SB(sb)->s_mount_state |= EXT4_FC_INELIGIBLE; atomic_dec(&EXT4_SB(sb)->s_fc_ineligible_updates); } static inline int ext4_fc_is_ineligible(struct super_block *sb) { return (EXT4_SB(sb)->s_mount_state & EXT4_FC_INELIGIBLE) || atomic_read(&EXT4_SB(sb)->s_fc_ineligible_updates); } /* * Generic fast commit tracking function. If this is the first time this we are * called after a full commit, we initialize fast commit fields and then call * __fc_track_fn() with update = 0. If we have already been called after a full * commit, we pass update = 1. Based on that, the track function can determine * if it needs to track a field for the first time or if it needs to just * update the previously tracked value. * * If enqueue is set, this function enqueues the inode in fast commit list. */ static int ext4_fc_track_template( struct inode *inode, int (*__fc_track_fn)(struct inode *, void *, bool), void *args, int enqueue) { tid_t running_txn_tid; bool update = false; struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); int ret; if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT)) return -EOPNOTSUPP; if (ext4_fc_is_ineligible(inode->i_sb)) return -EINVAL; running_txn_tid = sbi->s_journal ? sbi->s_journal->j_commit_sequence + 1 : 0; mutex_lock(&ei->i_fc_lock); if (running_txn_tid == ei->i_sync_tid) { update = true; } else { ext4_fc_reset_inode(inode); ei->i_sync_tid = running_txn_tid; } ret = __fc_track_fn(inode, args, update); mutex_unlock(&ei->i_fc_lock); if (!enqueue) return ret; spin_lock(&sbi->s_fc_lock); if (list_empty(&EXT4_I(inode)->i_fc_list)) list_add_tail(&EXT4_I(inode)->i_fc_list, (sbi->s_mount_state & EXT4_FC_COMMITTING) ? &sbi->s_fc_q[FC_Q_STAGING] : &sbi->s_fc_q[FC_Q_MAIN]); spin_unlock(&sbi->s_fc_lock); return ret; } struct __track_dentry_update_args { struct dentry *dentry; int op; }; /* __track_fn for directory entry updates. Called with ei->i_fc_lock. */ static int __track_dentry_update(struct inode *inode, void *arg, bool update) { struct ext4_fc_dentry_update *node; struct ext4_inode_info *ei = EXT4_I(inode); struct __track_dentry_update_args *dentry_update = (struct __track_dentry_update_args *)arg; struct dentry *dentry = dentry_update->dentry; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); mutex_unlock(&ei->i_fc_lock); node = kmem_cache_alloc(ext4_fc_dentry_cachep, GFP_NOFS); if (!node) { ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_MEM); mutex_lock(&ei->i_fc_lock); return -ENOMEM; } node->fcd_op = dentry_update->op; node->fcd_parent = dentry->d_parent->d_inode->i_ino; node->fcd_ino = inode->i_ino; if (dentry->d_name.len > DNAME_INLINE_LEN) { node->fcd_name.name = kmalloc(dentry->d_name.len, GFP_NOFS); if (!node->fcd_name.name) { kmem_cache_free(ext4_fc_dentry_cachep, node); ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_MEM); mutex_lock(&ei->i_fc_lock); return -ENOMEM; } memcpy((u8 *)node->fcd_name.name, dentry->d_name.name, dentry->d_name.len); } else { memcpy(node->fcd_iname, dentry->d_name.name, dentry->d_name.len); node->fcd_name.name = node->fcd_iname; } node->fcd_name.len = dentry->d_name.len; spin_lock(&sbi->s_fc_lock); if (sbi->s_mount_state & EXT4_FC_COMMITTING) list_add_tail(&node->fcd_list, &sbi->s_fc_dentry_q[FC_Q_STAGING]); else list_add_tail(&node->fcd_list, &sbi->s_fc_dentry_q[FC_Q_MAIN]); spin_unlock(&sbi->s_fc_lock); mutex_lock(&ei->i_fc_lock); return 0; } void ext4_fc_track_unlink(struct inode *inode, struct dentry *dentry) { struct __track_dentry_update_args args; int ret; args.dentry = dentry; args.op = EXT4_FC_TAG_UNLINK; ret = ext4_fc_track_template(inode, __track_dentry_update, (void *)&args, 0); trace_ext4_fc_track_unlink(inode, dentry, ret); } void ext4_fc_track_link(struct inode *inode, struct dentry *dentry) { struct __track_dentry_update_args args; int ret; args.dentry = dentry; args.op = EXT4_FC_TAG_LINK; ret = ext4_fc_track_template(inode, __track_dentry_update, (void *)&args, 0); trace_ext4_fc_track_link(inode, dentry, ret); } void ext4_fc_track_create(struct inode *inode, struct dentry *dentry) { struct __track_dentry_update_args args; int ret; args.dentry = dentry; args.op = EXT4_FC_TAG_CREAT; ret = ext4_fc_track_template(inode, __track_dentry_update, (void *)&args, 0); trace_ext4_fc_track_create(inode, dentry, ret); } /* __track_fn for inode tracking */ static int __track_inode(struct inode *inode, void *arg, bool update) { if (update) return -EEXIST; EXT4_I(inode)->i_fc_lblk_len = 0; return 0; } void ext4_fc_track_inode(struct inode *inode) { int ret; if (S_ISDIR(inode->i_mode)) return; ret = ext4_fc_track_template(inode, __track_inode, NULL, 1); trace_ext4_fc_track_inode(inode, ret); } struct __track_range_args { ext4_lblk_t start, end; }; /* __track_fn for tracking data updates */ static int __track_range(struct inode *inode, void *arg, bool update) { struct ext4_inode_info *ei = EXT4_I(inode); ext4_lblk_t oldstart; struct __track_range_args *__arg = (struct __track_range_args *)arg; if (inode->i_ino < EXT4_FIRST_INO(inode->i_sb)) { ext4_debug("Special inode %ld being modified\n", inode->i_ino); return -ECANCELED; } oldstart = ei->i_fc_lblk_start; if (update && ei->i_fc_lblk_len > 0) { ei->i_fc_lblk_start = min(ei->i_fc_lblk_start, __arg->start); ei->i_fc_lblk_len = max(oldstart + ei->i_fc_lblk_len - 1, __arg->end) - ei->i_fc_lblk_start + 1; } else { ei->i_fc_lblk_start = __arg->start; ei->i_fc_lblk_len = __arg->end - __arg->start + 1; } return 0; } void ext4_fc_track_range(struct inode *inode, ext4_lblk_t start, ext4_lblk_t end) { struct __track_range_args args; int ret; if (S_ISDIR(inode->i_mode)) return; args.start = start; args.end = end; ret = ext4_fc_track_template(inode, __track_range, &args, 1); trace_ext4_fc_track_range(inode, start, end, ret); } static void ext4_fc_submit_bh(struct super_block *sb) { int write_flags = REQ_SYNC; struct buffer_head *bh = EXT4_SB(sb)->s_fc_bh; if (test_opt(sb, BARRIER)) write_flags |= REQ_FUA | REQ_PREFLUSH; lock_buffer(bh); clear_buffer_dirty(bh); set_buffer_uptodate(bh); bh->b_end_io = ext4_end_buffer_io_sync; submit_bh(REQ_OP_WRITE, write_flags, bh); EXT4_SB(sb)->s_fc_bh = NULL; } /* Ext4 commit path routines */ /* memzero and update CRC */ static void *ext4_fc_memzero(struct super_block *sb, void *dst, int len, u32 *crc) { void *ret; ret = memset(dst, 0, len); if (crc) *crc = ext4_chksum(EXT4_SB(sb), *crc, dst, len); return ret; } /* * Allocate len bytes on a fast commit buffer. * * During the commit time this function is used to manage fast commit * block space. We don't split a fast commit log onto different * blocks. So this function makes sure that if there's not enough space * on the current block, the remaining space in the current block is * marked as unused by adding EXT4_FC_TAG_PAD tag. In that case, * new block is from jbd2 and CRC is updated to reflect the padding * we added. */ static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc) { struct ext4_fc_tl *tl; struct ext4_sb_info *sbi = EXT4_SB(sb); struct buffer_head *bh; int bsize = sbi->s_journal->j_blocksize; int ret, off = sbi->s_fc_bytes % bsize; int pad_len; /* * After allocating len, we should have space at least for a 0 byte * padding. */ if (len + sizeof(struct ext4_fc_tl) > bsize) return NULL; if (bsize - off - 1 > len + sizeof(struct ext4_fc_tl)) { /* * Only allocate from current buffer if we have enough space for * this request AND we have space to add a zero byte padding. */ if (!sbi->s_fc_bh) { ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh); if (ret) return NULL; sbi->s_fc_bh = bh; } sbi->s_fc_bytes += len; return sbi->s_fc_bh->b_data + off; } /* Need to add PAD tag */ tl = (struct ext4_fc_tl *)(sbi->s_fc_bh->b_data + off); tl->fc_tag = cpu_to_le16(EXT4_FC_TAG_PAD); pad_len = bsize - off - 1 - sizeof(struct ext4_fc_tl); tl->fc_len = cpu_to_le16(pad_len); if (crc) *crc = ext4_chksum(sbi, *crc, tl, sizeof(*tl)); if (pad_len > 0) ext4_fc_memzero(sb, tl + 1, pad_len, crc); ext4_fc_submit_bh(sb); ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh); if (ret) return NULL; sbi->s_fc_bh = bh; sbi->s_fc_bytes = (sbi->s_fc_bytes / bsize + 1) * bsize + len; return sbi->s_fc_bh->b_data; } /* memcpy to fc reserved space and update CRC */ static void *ext4_fc_memcpy(struct super_block *sb, void *dst, const void *src, int len, u32 *crc) { if (crc) *crc = ext4_chksum(EXT4_SB(sb), *crc, src, len); return memcpy(dst, src, len); } /* * Complete a fast commit by writing tail tag. * * Writing tail tag marks the end of a fast commit. In order to guarantee * atomicity, after writing tail tag, even if there's space remaining * in the block, next commit shouldn't use it. That's why tail tag * has the length as that of the remaining space on the block. */ static int ext4_fc_write_tail(struct super_block *sb, u32 crc) { struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_fc_tl tl; struct ext4_fc_tail tail; int off, bsize = sbi->s_journal->j_blocksize; u8 *dst; /* * ext4_fc_reserve_space takes care of allocating an extra block if * there's no enough space on this block for accommodating this tail. */ dst = ext4_fc_reserve_space(sb, sizeof(tl) + sizeof(tail), &crc); if (!dst) return -ENOSPC; off = sbi->s_fc_bytes % bsize; tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_TAIL); tl.fc_len = cpu_to_le16(bsize - off - 1 + sizeof(struct ext4_fc_tail)); sbi->s_fc_bytes = round_up(sbi->s_fc_bytes, bsize); ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), &crc); dst += sizeof(tl); tail.fc_tid = cpu_to_le32(sbi->s_journal->j_running_transaction->t_tid); ext4_fc_memcpy(sb, dst, &tail.fc_tid, sizeof(tail.fc_tid), &crc); dst += sizeof(tail.fc_tid); tail.fc_crc = cpu_to_le32(crc); ext4_fc_memcpy(sb, dst, &tail.fc_crc, sizeof(tail.fc_crc), NULL); ext4_fc_submit_bh(sb); return 0; } /* * Adds tag, length, value and updates CRC. Returns true if tlv was added. * Returns false if there's not enough space. */ static bool ext4_fc_add_tlv(struct super_block *sb, u16 tag, u16 len, u8 *val, u32 *crc) { struct ext4_fc_tl tl; u8 *dst; dst = ext4_fc_reserve_space(sb, sizeof(tl) + len, crc); if (!dst) return false; tl.fc_tag = cpu_to_le16(tag); tl.fc_len = cpu_to_le16(len); ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), crc); ext4_fc_memcpy(sb, dst + sizeof(tl), val, len, crc); return true; } /* Same as above, but adds dentry tlv. */ static bool ext4_fc_add_dentry_tlv(struct super_block *sb, u16 tag, int parent_ino, int ino, int dlen, const unsigned char *dname, u32 *crc) { struct ext4_fc_dentry_info fcd; struct ext4_fc_tl tl; u8 *dst = ext4_fc_reserve_space(sb, sizeof(tl) + sizeof(fcd) + dlen, crc); if (!dst) return false; fcd.fc_parent_ino = cpu_to_le32(parent_ino); fcd.fc_ino = cpu_to_le32(ino); tl.fc_tag = cpu_to_le16(tag); tl.fc_len = cpu_to_le16(sizeof(fcd) + dlen); ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), crc); dst += sizeof(tl); ext4_fc_memcpy(sb, dst, &fcd, sizeof(fcd), crc); dst += sizeof(fcd); ext4_fc_memcpy(sb, dst, dname, dlen, crc); dst += dlen; return true; } /* * Writes inode in the fast commit space under TLV with tag @tag. * Returns 0 on success, error on failure. */ static int ext4_fc_write_inode(struct inode *inode, u32 *crc) { struct ext4_inode_info *ei = EXT4_I(inode); int inode_len = EXT4_GOOD_OLD_INODE_SIZE; int ret; struct ext4_iloc iloc; struct ext4_fc_inode fc_inode; struct ext4_fc_tl tl; u8 *dst; ret = ext4_get_inode_loc(inode, &iloc); if (ret) return ret; if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) inode_len += ei->i_extra_isize; fc_inode.fc_ino = cpu_to_le32(inode->i_ino); tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_INODE); tl.fc_len = cpu_to_le16(inode_len + sizeof(fc_inode.fc_ino)); dst = ext4_fc_reserve_space(inode->i_sb, sizeof(tl) + inode_len + sizeof(fc_inode.fc_ino), crc); if (!dst) return -ECANCELED; if (!ext4_fc_memcpy(inode->i_sb, dst, &tl, sizeof(tl), crc)) return -ECANCELED; dst += sizeof(tl); if (!ext4_fc_memcpy(inode->i_sb, dst, &fc_inode, sizeof(fc_inode), crc)) return -ECANCELED; dst += sizeof(fc_inode); if (!ext4_fc_memcpy(inode->i_sb, dst, (u8 *)ext4_raw_inode(&iloc), inode_len, crc)) return -ECANCELED; return 0; } /* * Writes updated data ranges for the inode in question. Updates CRC. * Returns 0 on success, error otherwise. */ static int ext4_fc_write_inode_data(struct inode *inode, u32 *crc) { ext4_lblk_t old_blk_size, cur_lblk_off, new_blk_size; struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_map_blocks map; struct ext4_fc_add_range fc_ext; struct ext4_fc_del_range lrange; struct ext4_extent *ex; int ret; mutex_lock(&ei->i_fc_lock); if (ei->i_fc_lblk_len == 0) { mutex_unlock(&ei->i_fc_lock); return 0; } old_blk_size = ei->i_fc_lblk_start; new_blk_size = ei->i_fc_lblk_start + ei->i_fc_lblk_len - 1; ei->i_fc_lblk_len = 0; mutex_unlock(&ei->i_fc_lock); cur_lblk_off = old_blk_size; jbd_debug(1, "%s: will try writing %d to %d for inode %ld\n", __func__, cur_lblk_off, new_blk_size, inode->i_ino); while (cur_lblk_off <= new_blk_size) { map.m_lblk = cur_lblk_off; map.m_len = new_blk_size - cur_lblk_off + 1; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) return -ECANCELED; if (map.m_len == 0) { cur_lblk_off++; continue; } if (ret == 0) { lrange.fc_ino = cpu_to_le32(inode->i_ino); lrange.fc_lblk = cpu_to_le32(map.m_lblk); lrange.fc_len = cpu_to_le32(map.m_len); if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_DEL_RANGE, sizeof(lrange), (u8 *)&lrange, crc)) return -ENOSPC; } else { fc_ext.fc_ino = cpu_to_le32(inode->i_ino); ex = (struct ext4_extent *)&fc_ext.fc_ex; ex->ee_block = cpu_to_le32(map.m_lblk); ex->ee_len = cpu_to_le16(map.m_len); ext4_ext_store_pblock(ex, map.m_pblk); if (map.m_flags & EXT4_MAP_UNWRITTEN) ext4_ext_mark_unwritten(ex); else ext4_ext_mark_initialized(ex); if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_ADD_RANGE, sizeof(fc_ext), (u8 *)&fc_ext, crc)) return -ENOSPC; } cur_lblk_off += map.m_len; } return 0; } /* Submit data for all the fast commit inodes */ static int ext4_fc_submit_inode_data_all(journal_t *journal) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *ei; struct list_head *pos; int ret = 0; spin_lock(&sbi->s_fc_lock); sbi->s_mount_state |= EXT4_FC_COMMITTING; list_for_each(pos, &sbi->s_fc_q[FC_Q_MAIN]) { ei = list_entry(pos, struct ext4_inode_info, i_fc_list); ext4_set_inode_state(&ei->vfs_inode, EXT4_STATE_FC_COMMITTING); while (atomic_read(&ei->i_fc_updates)) { DEFINE_WAIT(wait); prepare_to_wait(&ei->i_fc_wait, &wait, TASK_UNINTERRUPTIBLE); if (atomic_read(&ei->i_fc_updates)) { spin_unlock(&sbi->s_fc_lock); schedule(); spin_lock(&sbi->s_fc_lock); } finish_wait(&ei->i_fc_wait, &wait); } spin_unlock(&sbi->s_fc_lock); ret = jbd2_submit_inode_data(ei->jinode); if (ret) return ret; spin_lock(&sbi->s_fc_lock); } spin_unlock(&sbi->s_fc_lock); return ret; } /* Wait for completion of data for all the fast commit inodes */ static int ext4_fc_wait_inode_data_all(journal_t *journal) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *pos, *n; int ret = 0; spin_lock(&sbi->s_fc_lock); list_for_each_entry_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) { if (!ext4_test_inode_state(&pos->vfs_inode, EXT4_STATE_FC_COMMITTING)) continue; spin_unlock(&sbi->s_fc_lock); ret = jbd2_wait_inode_data(journal, pos->jinode); if (ret) return ret; spin_lock(&sbi->s_fc_lock); } spin_unlock(&sbi->s_fc_lock); return 0; } /* Commit all the directory entry updates */ static int ext4_fc_commit_dentry_updates(journal_t *journal, u32 *crc) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_fc_dentry_update *fc_dentry; struct inode *inode; struct list_head *pos, *n, *fcd_pos, *fcd_n; struct ext4_inode_info *ei; int ret; if (list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN])) return 0; list_for_each_safe(fcd_pos, fcd_n, &sbi->s_fc_dentry_q[FC_Q_MAIN]) { fc_dentry = list_entry(fcd_pos, struct ext4_fc_dentry_update, fcd_list); if (fc_dentry->fcd_op != EXT4_FC_TAG_CREAT) { spin_unlock(&sbi->s_fc_lock); if (!ext4_fc_add_dentry_tlv( sb, fc_dentry->fcd_op, fc_dentry->fcd_parent, fc_dentry->fcd_ino, fc_dentry->fcd_name.len, fc_dentry->fcd_name.name, crc)) { ret = -ENOSPC; goto lock_and_exit; } spin_lock(&sbi->s_fc_lock); continue; } inode = NULL; list_for_each_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN]) { ei = list_entry(pos, struct ext4_inode_info, i_fc_list); if (ei->vfs_inode.i_ino == fc_dentry->fcd_ino) { inode = &ei->vfs_inode; break; } } /* * If we don't find inode in our list, then it was deleted, * in which case, we don't need to record it's create tag. */ if (!inode) continue; spin_unlock(&sbi->s_fc_lock); /* * We first write the inode and then the create dirent. This * allows the recovery code to create an unnamed inode first * and then link it to a directory entry. This allows us * to use namei.c routines almost as is and simplifies * the recovery code. */ ret = ext4_fc_write_inode(inode, crc); if (ret) goto lock_and_exit; ret = ext4_fc_write_inode_data(inode, crc); if (ret) goto lock_and_exit; if (!ext4_fc_add_dentry_tlv( sb, fc_dentry->fcd_op, fc_dentry->fcd_parent, fc_dentry->fcd_ino, fc_dentry->fcd_name.len, fc_dentry->fcd_name.name, crc)) { spin_lock(&sbi->s_fc_lock); ret = -ENOSPC; goto lock_and_exit; } spin_lock(&sbi->s_fc_lock); } return 0; lock_and_exit: spin_lock(&sbi->s_fc_lock); return ret; } static int ext4_fc_perform_commit(journal_t *journal) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *iter; struct ext4_fc_head head; struct list_head *pos; struct inode *inode; struct blk_plug plug; int ret = 0; u32 crc = 0; ret = ext4_fc_submit_inode_data_all(journal); if (ret) return ret; ret = ext4_fc_wait_inode_data_all(journal); if (ret) return ret; blk_start_plug(&plug); if (sbi->s_fc_bytes == 0) { /* * Add a head tag only if this is the first fast commit * in this TID. */ head.fc_features = cpu_to_le32(EXT4_FC_SUPPORTED_FEATURES); head.fc_tid = cpu_to_le32( sbi->s_journal->j_running_transaction->t_tid); if (!ext4_fc_add_tlv(sb, EXT4_FC_TAG_HEAD, sizeof(head), (u8 *)&head, &crc)) goto out; } spin_lock(&sbi->s_fc_lock); ret = ext4_fc_commit_dentry_updates(journal, &crc); if (ret) { spin_unlock(&sbi->s_fc_lock); goto out; } list_for_each(pos, &sbi->s_fc_q[FC_Q_MAIN]) { iter = list_entry(pos, struct ext4_inode_info, i_fc_list); inode = &iter->vfs_inode; if (!ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) continue; spin_unlock(&sbi->s_fc_lock); ret = ext4_fc_write_inode_data(inode, &crc); if (ret) goto out; ret = ext4_fc_write_inode(inode, &crc); if (ret) goto out; spin_lock(&sbi->s_fc_lock); EXT4_I(inode)->i_fc_committed_subtid = atomic_read(&sbi->s_fc_subtid); } spin_unlock(&sbi->s_fc_lock); ret = ext4_fc_write_tail(sb, crc); out: blk_finish_plug(&plug); return ret; } /* * The main commit entry point. Performs a fast commit for transaction * commit_tid if needed. If it's not possible to perform a fast commit * due to various reasons, we fall back to full commit. Returns 0 * on success, error otherwise. */ int ext4_fc_commit(journal_t *journal, tid_t commit_tid) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); int nblks = 0, ret, bsize = journal->j_blocksize; int subtid = atomic_read(&sbi->s_fc_subtid); int reason = EXT4_FC_REASON_OK, fc_bufs_before = 0; ktime_t start_time, commit_time; trace_ext4_fc_commit_start(sb); start_time = ktime_get(); if (!test_opt2(sb, JOURNAL_FAST_COMMIT) || (ext4_fc_is_ineligible(sb))) { reason = EXT4_FC_REASON_INELIGIBLE; goto out; } restart_fc: ret = jbd2_fc_begin_commit(journal, commit_tid); if (ret == -EALREADY) { /* There was an ongoing commit, check if we need to restart */ if (atomic_read(&sbi->s_fc_subtid) <= subtid && commit_tid > journal->j_commit_sequence) goto restart_fc; reason = EXT4_FC_REASON_ALREADY_COMMITTED; goto out; } else if (ret) { sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++; reason = EXT4_FC_REASON_FC_START_FAILED; goto out; } fc_bufs_before = (sbi->s_fc_bytes + bsize - 1) / bsize; ret = ext4_fc_perform_commit(journal); if (ret < 0) { sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++; reason = EXT4_FC_REASON_FC_FAILED; goto out; } nblks = (sbi->s_fc_bytes + bsize - 1) / bsize - fc_bufs_before; ret = jbd2_fc_wait_bufs(journal, nblks); if (ret < 0) { sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++; reason = EXT4_FC_REASON_FC_FAILED; goto out; } atomic_inc(&sbi->s_fc_subtid); jbd2_fc_end_commit(journal); out: /* Has any ineligible update happened since we started? */ if (reason == EXT4_FC_REASON_OK && ext4_fc_is_ineligible(sb)) { sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++; reason = EXT4_FC_REASON_INELIGIBLE; } spin_lock(&sbi->s_fc_lock); if (reason != EXT4_FC_REASON_OK && reason != EXT4_FC_REASON_ALREADY_COMMITTED) { sbi->s_fc_stats.fc_ineligible_commits++; } else { sbi->s_fc_stats.fc_num_commits++; sbi->s_fc_stats.fc_numblks += nblks; } spin_unlock(&sbi->s_fc_lock); nblks = (reason == EXT4_FC_REASON_OK) ? nblks : 0; trace_ext4_fc_commit_stop(sb, nblks, reason); commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time)); /* * weight the commit time higher than the average time so we don't * react too strongly to vast changes in the commit time */ if (likely(sbi->s_fc_avg_commit_time)) sbi->s_fc_avg_commit_time = (commit_time + sbi->s_fc_avg_commit_time * 3) / 4; else sbi->s_fc_avg_commit_time = commit_time; jbd_debug(1, "Fast commit ended with blks = %d, reason = %d, subtid - %d", nblks, reason, subtid); if (reason == EXT4_FC_REASON_FC_FAILED) return jbd2_fc_end_commit_fallback(journal, commit_tid); if (reason == EXT4_FC_REASON_FC_START_FAILED || reason == EXT4_FC_REASON_INELIGIBLE) return jbd2_complete_transaction(journal, commit_tid); return 0; } /* * Fast commit cleanup routine. This is called after every fast commit and * full commit. full is true if we are called after a full commit. */ static void ext4_fc_cleanup(journal_t *journal, int full) { struct super_block *sb = journal->j_private; struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *iter; struct ext4_fc_dentry_update *fc_dentry; struct list_head *pos, *n; if (full && sbi->s_fc_bh) sbi->s_fc_bh = NULL; jbd2_fc_release_bufs(journal); spin_lock(&sbi->s_fc_lock); list_for_each_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN]) { iter = list_entry(pos, struct ext4_inode_info, i_fc_list); list_del_init(&iter->i_fc_list); ext4_clear_inode_state(&iter->vfs_inode, EXT4_STATE_FC_COMMITTING); ext4_fc_reset_inode(&iter->vfs_inode); /* Make sure EXT4_STATE_FC_COMMITTING bit is clear */ smp_mb(); #if (BITS_PER_LONG < 64) wake_up_bit(&iter->i_state_flags, EXT4_STATE_FC_COMMITTING); #else wake_up_bit(&iter->i_flags, EXT4_STATE_FC_COMMITTING); #endif } while (!list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN])) { fc_dentry = list_first_entry(&sbi->s_fc_dentry_q[FC_Q_MAIN], struct ext4_fc_dentry_update, fcd_list); list_del_init(&fc_dentry->fcd_list); spin_unlock(&sbi->s_fc_lock); if (fc_dentry->fcd_name.name && fc_dentry->fcd_name.len > DNAME_INLINE_LEN) kfree(fc_dentry->fcd_name.name); kmem_cache_free(ext4_fc_dentry_cachep, fc_dentry); spin_lock(&sbi->s_fc_lock); } list_splice_init(&sbi->s_fc_dentry_q[FC_Q_STAGING], &sbi->s_fc_dentry_q[FC_Q_MAIN]); list_splice_init(&sbi->s_fc_q[FC_Q_STAGING], &sbi->s_fc_q[FC_Q_STAGING]); sbi->s_mount_state &= ~EXT4_FC_COMMITTING; sbi->s_mount_state &= ~EXT4_FC_INELIGIBLE; if (full) sbi->s_fc_bytes = 0; spin_unlock(&sbi->s_fc_lock); trace_ext4_fc_stats(sb); } /* * Main recovery path entry point. */ static int ext4_fc_replay(journal_t *journal, struct buffer_head *bh, enum passtype pass, int off, tid_t expected_tid) { return 0; } void ext4_fc_init(struct super_block *sb, journal_t *journal) { /* * We set replay callback even if fast commit disabled because we may * could still have fast commit blocks that need to be replayed even if * fast commit has now been turned off. */ journal->j_fc_replay_callback = ext4_fc_replay; if (!test_opt2(sb, JOURNAL_FAST_COMMIT)) return; journal->j_fc_cleanup_callback = ext4_fc_cleanup; if (jbd2_fc_init(journal, EXT4_NUM_FC_BLKS)) { pr_warn("Error while enabling fast commits, turning off."); ext4_clear_feature_fast_commit(sb); } } int __init ext4_fc_init_dentry_cache(void) { ext4_fc_dentry_cachep = KMEM_CACHE(ext4_fc_dentry_update, SLAB_RECLAIM_ACCOUNT); if (ext4_fc_dentry_cachep == NULL) return -ENOMEM; return 0; }