From 30a7eb970c3aae6f1b74b2edea896fdca1cbea38 Mon Sep 17 00:00:00 2001 From: Tahsin Erdogan Date: Thu, 22 Jun 2017 11:42:09 -0400 Subject: ext4: cleanup transaction restarts during inode deletion During inode deletion, the number of journal credits that will be needed is hard to determine. For that reason we have journal extend/restart calls in several places. Whenever a transaction is restarted, filesystem must be in a consistent state because there is no atomicity guarantee beyond a restart call. Add ext4_xattr_ensure_credits() helper function which takes care of journal extend/restart logic. It also handles getting jbd2 write access and dirty metadata calls. This function is called at every iteration of handling an ea_inode reference. Signed-off-by: Tahsin Erdogan Signed-off-by: Theodore Ts'o --- fs/ext4/xattr.c | 258 ++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 165 insertions(+), 93 deletions(-) (limited to 'fs/ext4/xattr.c') diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 53980ee164ed..649dc2953901 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -108,6 +108,10 @@ const struct xattr_handler *ext4_xattr_handlers[] = { #define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \ inode->i_sb->s_fs_info)->s_ea_block_cache) +static int +ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, + struct inode *inode); + #ifdef CONFIG_LOCKDEP void ext4_xattr_inode_set_class(struct inode *ea_inode) { @@ -652,6 +656,128 @@ static void ext4_xattr_update_super_block(handle_t *handle, } } +static int ext4_xattr_ensure_credits(handle_t *handle, struct inode *inode, + int credits, struct buffer_head *bh, + bool dirty, bool block_csum) +{ + int error; + + if (!ext4_handle_valid(handle)) + return 0; + + if (handle->h_buffer_credits >= credits) + return 0; + + error = ext4_journal_extend(handle, credits - handle->h_buffer_credits); + if (!error) + return 0; + if (error < 0) { + ext4_warning(inode->i_sb, "Extend journal (error %d)", error); + return error; + } + + if (bh && dirty) { + if (block_csum) + ext4_xattr_block_csum_set(inode, bh); + error = ext4_handle_dirty_metadata(handle, NULL, bh); + if (error) { + ext4_warning(inode->i_sb, "Handle metadata (error %d)", + error); + return error; + } + } + + error = ext4_journal_restart(handle, credits); + if (error) { + ext4_warning(inode->i_sb, "Restart journal (error %d)", error); + return error; + } + + if (bh) { + error = ext4_journal_get_write_access(handle, bh); + if (error) { + ext4_warning(inode->i_sb, + "Get write access failed (error %d)", + error); + return error; + } + } + return 0; +} + +static void +ext4_xattr_inode_remove_all(handle_t *handle, struct inode *parent, + struct buffer_head *bh, + struct ext4_xattr_entry *first, bool block_csum, + struct ext4_xattr_inode_array **ea_inode_array, + int extra_credits) +{ + struct inode *ea_inode; + struct ext4_xattr_entry *entry; + bool dirty = false; + unsigned int ea_ino; + int err; + int credits; + + /* One credit for dec ref on ea_inode, one for orphan list addition, */ + credits = 2 + extra_credits; + + for (entry = first; !IS_LAST_ENTRY(entry); + entry = EXT4_XATTR_NEXT(entry)) { + if (!entry->e_value_inum) + continue; + ea_ino = le32_to_cpu(entry->e_value_inum); + err = ext4_xattr_inode_iget(parent, ea_ino, &ea_inode); + if (err) + continue; + + err = ext4_expand_inode_array(ea_inode_array, ea_inode); + if (err) { + ext4_warning_inode(ea_inode, + "Expand inode array err=%d", err); + iput(ea_inode); + continue; + } + + err = ext4_xattr_ensure_credits(handle, parent, credits, bh, + dirty, block_csum); + if (err) { + ext4_warning_inode(ea_inode, "Ensure credits err=%d", + err); + continue; + } + + inode_lock(ea_inode); + clear_nlink(ea_inode); + ext4_orphan_add(handle, ea_inode); + inode_unlock(ea_inode); + + /* + * Forget about ea_inode within the same transaction that + * decrements the ref count. This avoids duplicate decrements in + * case the rest of the work spills over to subsequent + * transactions. + */ + entry->e_value_inum = 0; + entry->e_value_size = 0; + + dirty = true; + } + + if (dirty) { + /* + * Note that we are deliberately skipping csum calculation for + * the final update because we do not expect any journal + * restarts until xattr block is freed. + */ + + err = ext4_handle_dirty_metadata(handle, NULL, bh); + if (err) + ext4_warning_inode(parent, + "handle dirty metadata err=%d", err); + } +} + /* * Release the xattr block BH: If the reference count is > 1, decrement it; * otherwise free the block. @@ -1982,42 +2108,6 @@ ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array, return 0; } -/** - * Add xattr inode to orphan list - */ -static int -ext4_xattr_inode_orphan_add(handle_t *handle, struct inode *inode, int credits, - struct ext4_xattr_inode_array *ea_inode_array) -{ - int idx = 0, error = 0; - struct inode *ea_inode; - - if (ea_inode_array == NULL) - return 0; - - for (; idx < ea_inode_array->count; ++idx) { - if (!ext4_handle_has_enough_credits(handle, credits)) { - error = ext4_journal_extend(handle, credits); - if (error > 0) - error = ext4_journal_restart(handle, credits); - - if (error != 0) { - ext4_warning(inode->i_sb, - "couldn't extend journal " - "(err %d)", error); - return error; - } - } - ea_inode = ea_inode_array->inodes[idx]; - inode_lock(ea_inode); - ext4_orphan_add(handle, ea_inode); - inode_unlock(ea_inode); - /* the inode's i_count will be released by caller */ - } - - return 0; -} - /* * ext4_xattr_delete_inode() * @@ -2030,16 +2120,23 @@ ext4_xattr_inode_orphan_add(handle_t *handle, struct inode *inode, int credits, */ int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, - struct ext4_xattr_inode_array **ea_inode_array) + struct ext4_xattr_inode_array **ea_inode_array, + int extra_credits) { struct buffer_head *bh = NULL; struct ext4_xattr_ibody_header *header; struct ext4_inode *raw_inode; - struct ext4_iloc iloc; - struct ext4_xattr_entry *entry; - struct inode *ea_inode; - unsigned int ea_ino; - int credits = 3, error = 0; + struct ext4_iloc iloc = { .bh = NULL }; + int error; + + error = ext4_xattr_ensure_credits(handle, inode, extra_credits, + NULL /* bh */, + false /* dirty */, + false /* block_csum */); + if (error) { + EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error); + goto cleanup; + } if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) goto delete_external_ea; @@ -2047,31 +2144,20 @@ ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, error = ext4_get_inode_loc(inode, &iloc); if (error) goto cleanup; + + error = ext4_journal_get_write_access(handle, iloc.bh); + if (error) + goto cleanup; + raw_inode = ext4_raw_inode(&iloc); header = IHDR(inode, raw_inode); - for (entry = IFIRST(header); !IS_LAST_ENTRY(entry); - entry = EXT4_XATTR_NEXT(entry)) { - if (!entry->e_value_inum) - continue; - ea_ino = le32_to_cpu(entry->e_value_inum); - error = ext4_xattr_inode_iget(inode, ea_ino, &ea_inode); - if (error) - continue; - error = ext4_expand_inode_array(ea_inode_array, ea_inode); - if (error) { - iput(ea_inode); - brelse(iloc.bh); - goto cleanup; - } - entry->e_value_inum = 0; - } - brelse(iloc.bh); + ext4_xattr_inode_remove_all(handle, inode, iloc.bh, IFIRST(header), + false /* block_csum */, ea_inode_array, + extra_credits); delete_external_ea: if (!EXT4_I(inode)->i_file_acl) { - /* add xattr inode to orphan list */ - error = ext4_xattr_inode_orphan_add(handle, inode, credits, - *ea_inode_array); + error = 0; goto cleanup; } bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); @@ -2089,46 +2175,32 @@ delete_external_ea: goto cleanup; } - for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry); - entry = EXT4_XATTR_NEXT(entry)) { - if (!entry->e_value_inum) - continue; - ea_ino = le32_to_cpu(entry->e_value_inum); - error = ext4_xattr_inode_iget(inode, ea_ino, &ea_inode); - if (error) - continue; - error = ext4_expand_inode_array(ea_inode_array, ea_inode); - if (error) - goto cleanup; - entry->e_value_inum = 0; - } - - /* add xattr inode to orphan list */ - error = ext4_xattr_inode_orphan_add(handle, inode, credits, - *ea_inode_array); - if (error) - goto cleanup; - - if (!IS_NOQUOTA(inode)) - credits += 2 * EXT4_QUOTA_DEL_BLOCKS(inode->i_sb); - - if (!ext4_handle_has_enough_credits(handle, credits)) { - error = ext4_journal_extend(handle, credits); - if (error > 0) - error = ext4_journal_restart(handle, credits); + if (ext4_has_feature_ea_inode(inode->i_sb)) { + error = ext4_journal_get_write_access(handle, bh); if (error) { - ext4_warning(inode->i_sb, - "couldn't extend journal (err %d)", error); + EXT4_ERROR_INODE(inode, "write access %llu", + EXT4_I(inode)->i_file_acl); goto cleanup; } + ext4_xattr_inode_remove_all(handle, inode, bh, + BFIRST(bh), + true /* block_csum */, + ea_inode_array, + extra_credits); } ext4_xattr_release_block(handle, inode, bh); + /* Update i_file_acl within the same transaction that releases block. */ EXT4_I(inode)->i_file_acl = 0; - + error = ext4_mark_inode_dirty(handle, inode); + if (error) { + EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)", + error); + goto cleanup; + } cleanup: + brelse(iloc.bh); brelse(bh); - return error; } -- cgit v1.2.3-55-g7522