From 278f6679f454bf185a07d9a4ca355b153482d17a Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 8 Aug 2013 17:34:46 -0400 Subject: reiserfs: locking, handle nested locks properly The reiserfs write lock replaced the BKL and uses similar semantics. Frederic's locking code makes a distinction between when the lock is nested and when it's being acquired/released, but I don't think that's the right distinction to make. The right distinction is between the lock being released at end-of-use and the lock being released for a schedule. The unlock should return the depth and the lock should restore it, rather than the other way around as it is now. This patch implements that and adds a number of places where the lock should be dropped. Signed-off-by: Jeff Mahoney --- fs/reiserfs/inode.c | 77 +++++++++++++++++++++++++---------------------------- 1 file changed, 36 insertions(+), 41 deletions(-) (limited to 'fs/reiserfs/inode.c') diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index bf1331a..4a3a57c 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -41,11 +41,10 @@ void reiserfs_evict_inode(struct inode *inode) /* The = 0 happens when we abort creating a new inode for some reason like lack of space.. */ if (!(inode->i_state & I_NEW) && INODE_PKEY(inode)->k_objectid != 0) { /* also handles bad_inode case */ - int depth; reiserfs_delete_xattrs(inode); - depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); if (journal_begin(&th, inode->i_sb, jbegin_count)) goto out; @@ -74,7 +73,7 @@ void reiserfs_evict_inode(struct inode *inode) remove_save_link(inode, 0 /* not truncate */ ); /* we can't do anything * about an error here */ out: - reiserfs_write_unlock_once(inode->i_sb, depth); + reiserfs_write_unlock(inode->i_sb); } else { /* no object items are in the tree */ ; @@ -611,7 +610,6 @@ int reiserfs_get_block(struct inode *inode, sector_t block, __le32 *item; int done; int fs_gen; - int lock_depth; struct reiserfs_transaction_handle *th = NULL; /* space reserved in transaction batch: . 3 balancings in direct->indirect conversion @@ -627,11 +625,11 @@ int reiserfs_get_block(struct inode *inode, sector_t block, loff_t new_offset = (((loff_t) block) << inode->i_sb->s_blocksize_bits) + 1; - lock_depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); version = get_inode_item_key_version(inode); if (!file_capable(inode, block)) { - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); return -EFBIG; } @@ -643,7 +641,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, /* find number of block-th logical block of the file */ ret = _get_block_create_0(inode, block, bh_result, create | GET_BLOCK_READ_DIRECT); - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); return ret; } /* @@ -761,7 +759,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, if (!dangle && th) retval = reiserfs_end_persistent_transaction(th); - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); /* the item was found, so new blocks were not added to the file ** there is no need to make sure the inode is updated with this @@ -1012,11 +1010,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, * long time. reschedule if needed and also release the write * lock for others. */ - if (need_resched()) { - reiserfs_write_unlock_once(inode->i_sb, lock_depth); - schedule(); - lock_depth = reiserfs_write_lock_once(inode->i_sb); - } + reiserfs_cond_resched(inode->i_sb); retval = search_for_position_by_key(inode->i_sb, &key, &path); if (retval == IO_ERROR) { @@ -1051,7 +1045,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, retval = err; } - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); reiserfs_check_path(&path); return retval; } @@ -1510,14 +1504,15 @@ struct inode *reiserfs_iget(struct super_block *s, const struct cpu_key *key) { struct inode *inode; struct reiserfs_iget_args args; + int depth; args.objectid = key->on_disk_key.k_objectid; args.dirid = key->on_disk_key.k_dir_id; - reiserfs_write_unlock(s); + depth = reiserfs_write_unlock_nested(s); inode = iget5_locked(s, key->on_disk_key.k_objectid, reiserfs_find_actor, reiserfs_init_locked_inode, (void *)(&args)); - reiserfs_write_lock(s); + reiserfs_write_lock_nested(s, depth); if (!inode) return ERR_PTR(-ENOMEM); @@ -1781,6 +1776,7 @@ int reiserfs_new_inode(struct reiserfs_transaction_handle *th, struct stat_data sd; int retval; int err; + int depth; BUG_ON(!th->t_trans_id); @@ -1813,10 +1809,10 @@ int reiserfs_new_inode(struct reiserfs_transaction_handle *th, memcpy(INODE_PKEY(inode), &(ih.ih_key), KEY_SIZE); args.dirid = le32_to_cpu(ih.ih_key.k_dir_id); - reiserfs_write_unlock(inode->i_sb); + depth = reiserfs_write_unlock_nested(inode->i_sb); err = insert_inode_locked4(inode, args.objectid, reiserfs_find_actor, &args); - reiserfs_write_lock(inode->i_sb); + reiserfs_write_lock_nested(inode->i_sb, depth); if (err) { err = -EINVAL; goto out_bad_inode; @@ -2108,9 +2104,8 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps) int error; struct buffer_head *bh = NULL; int err2; - int lock_depth; - lock_depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); if (inode->i_size > 0) { error = grab_tail_page(inode, &page, &bh); @@ -2179,7 +2174,7 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps) page_cache_release(page); } - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); return 0; out: @@ -2188,7 +2183,7 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps) page_cache_release(page); } - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); return error; } @@ -2653,10 +2648,11 @@ int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len) struct inode *inode = page->mapping->host; int ret; int old_ref = 0; + int depth; - reiserfs_write_unlock(inode->i_sb); + depth = reiserfs_write_unlock_nested(inode->i_sb); reiserfs_wait_on_write_block(inode->i_sb); - reiserfs_write_lock(inode->i_sb); + reiserfs_write_lock_nested(inode->i_sb, depth); fix_tail_page_for_writing(page); if (reiserfs_transaction_running(inode->i_sb)) { @@ -2713,7 +2709,6 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, int update_sd = 0; struct reiserfs_transaction_handle *th; unsigned start; - int lock_depth = 0; bool locked = false; if ((unsigned long)fsdata & AOP_FLAG_CONT_EXPAND) @@ -2742,7 +2737,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, */ if (pos + copied > inode->i_size) { struct reiserfs_transaction_handle myth; - lock_depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); locked = true; /* If the file have grown beyond the border where it can have a tail, unmark it as needing a tail @@ -2773,7 +2768,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, } if (th) { if (!locked) { - lock_depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); locked = true; } if (!update_sd) @@ -2785,7 +2780,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, out: if (locked) - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); unlock_page(page); page_cache_release(page); @@ -2795,7 +2790,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, return ret == 0 ? copied : ret; journal_error: - reiserfs_write_unlock_once(inode->i_sb, lock_depth); + reiserfs_write_unlock(inode->i_sb); locked = false; if (th) { if (!update_sd) @@ -2813,10 +2808,11 @@ int reiserfs_commit_write(struct file *f, struct page *page, int ret = 0; int update_sd = 0; struct reiserfs_transaction_handle *th = NULL; + int depth; - reiserfs_write_unlock(inode->i_sb); + depth = reiserfs_write_unlock_nested(inode->i_sb); reiserfs_wait_on_write_block(inode->i_sb); - reiserfs_write_lock(inode->i_sb); + reiserfs_write_lock_nested(inode->i_sb, depth); if (reiserfs_transaction_running(inode->i_sb)) { th = current->journal_info; @@ -3115,7 +3111,6 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; unsigned int ia_valid; - int depth; int error; error = inode_change_ok(inode, attr); @@ -3127,14 +3122,14 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) if (is_quota_modification(inode, attr)) dquot_initialize(inode); - depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); if (attr->ia_valid & ATTR_SIZE) { /* version 2 items will be caught by the s_maxbytes check ** done for us in vmtruncate */ if (get_inode_item_key_version(inode) == KEY_FORMAT_3_5 && attr->ia_size > MAX_NON_LFS) { - reiserfs_write_unlock_once(inode->i_sb, depth); + reiserfs_write_unlock(inode->i_sb); error = -EFBIG; goto out; } @@ -3157,7 +3152,7 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) error = err; } if (error) { - reiserfs_write_unlock_once(inode->i_sb, depth); + reiserfs_write_unlock(inode->i_sb); goto out; } /* @@ -3167,7 +3162,7 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) attr->ia_valid |= (ATTR_MTIME | ATTR_CTIME); } } - reiserfs_write_unlock_once(inode->i_sb, depth); + reiserfs_write_unlock(inode->i_sb); if ((((attr->ia_valid & ATTR_UID) && (from_kuid(&init_user_ns, attr->ia_uid) & ~0xffff)) || ((attr->ia_valid & ATTR_GID) && (from_kgid(&init_user_ns, attr->ia_gid) & ~0xffff))) && @@ -3192,16 +3187,16 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) return error; /* (user+group)*(old+new) structure - we count quota info and , inode write (sb, inode) */ - depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); error = journal_begin(&th, inode->i_sb, jbegin_count); - reiserfs_write_unlock_once(inode->i_sb, depth); + reiserfs_write_unlock(inode->i_sb); if (error) goto out; error = dquot_transfer(inode, attr); - depth = reiserfs_write_lock_once(inode->i_sb); + reiserfs_write_lock(inode->i_sb); if (error) { journal_end(&th, inode->i_sb, jbegin_count); - reiserfs_write_unlock_once(inode->i_sb, depth); + reiserfs_write_unlock(inode->i_sb); goto out; } @@ -3213,7 +3208,7 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) inode->i_gid = attr->ia_gid; mark_inode_dirty(inode); error = journal_end(&th, inode->i_sb, jbegin_count); - reiserfs_write_unlock_once(inode->i_sb, depth); + reiserfs_write_unlock(inode->i_sb); if (error) goto out; } -- cgit v1.1