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/namei.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) (limited to 'fs/reiserfs/namei.c') diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c index 8567fb847601..dc5236f6de1b 100644 --- a/fs/reiserfs/namei.c +++ b/fs/reiserfs/namei.c @@ -325,7 +325,6 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { int retval; - int lock_depth; struct inode *inode = NULL; struct reiserfs_dir_entry de; INITIALIZE_PATH(path_to_entry); @@ -333,12 +332,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, if (REISERFS_MAX_NAME(dir->i_sb->s_blocksize) < dentry->d_name.len) return ERR_PTR(-ENAMETOOLONG); - /* - * Might be called with or without the write lock, must be careful - * to not recursively hold it in case we want to release the lock - * before rescheduling. - */ - lock_depth = reiserfs_write_lock_once(dir->i_sb); + reiserfs_write_lock(dir->i_sb); de.de_gen_number_bit_string = NULL; retval = @@ -349,7 +343,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, inode = reiserfs_iget(dir->i_sb, (struct cpu_key *)&(de.de_dir_id)); if (!inode || IS_ERR(inode)) { - reiserfs_write_unlock_once(dir->i_sb, lock_depth); + reiserfs_write_unlock(dir->i_sb); return ERR_PTR(-EACCES); } @@ -358,7 +352,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry, if (IS_PRIVATE(dir)) inode->i_flags |= S_PRIVATE; } - reiserfs_write_unlock_once(dir->i_sb, lock_depth); + reiserfs_write_unlock(dir->i_sb); if (retval == IO_ERROR) { return ERR_PTR(-EIO); } @@ -727,7 +721,6 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode struct inode *inode; struct reiserfs_transaction_handle th; struct reiserfs_security_handle security; - int lock_depth; /* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */ int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3 + @@ -753,7 +746,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode return retval; } jbegin_count += retval; - lock_depth = reiserfs_write_lock_once(dir->i_sb); + reiserfs_write_lock(dir->i_sb); retval = journal_begin(&th, dir->i_sb, jbegin_count); if (retval) { @@ -804,7 +797,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode d_instantiate(dentry, inode); retval = journal_end(&th, dir->i_sb, jbegin_count); out_failed: - reiserfs_write_unlock_once(dir->i_sb, lock_depth); + reiserfs_write_unlock(dir->i_sb); return retval; } @@ -920,7 +913,6 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry) struct reiserfs_transaction_handle th; int jbegin_count; unsigned long savelink; - int depth; dquot_initialize(dir); @@ -934,7 +926,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry) JOURNAL_PER_BALANCE_CNT * 2 + 2 + 4 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb); - depth = reiserfs_write_lock_once(dir->i_sb); + reiserfs_write_lock(dir->i_sb); retval = journal_begin(&th, dir->i_sb, jbegin_count); if (retval) goto out_unlink; @@ -995,7 +987,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry) retval = journal_end(&th, dir->i_sb, jbegin_count); reiserfs_check_path(&path); - reiserfs_write_unlock_once(dir->i_sb, depth); + reiserfs_write_unlock(dir->i_sb); return retval; end_unlink: @@ -1005,7 +997,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry) if (err) retval = err; out_unlink: - reiserfs_write_unlock_once(dir->i_sb, depth); + reiserfs_write_unlock(dir->i_sb); return retval; } -- cgit