From 0e4f6a791b1e8cfde75a74e2f885642ecb3fe9d8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 4 Jul 2010 12:18:57 +0400 Subject: Fix reiserfs_file_release() a) count file openers correctly; i_count use was completely wrong b) use new mutex for exclusion between final close/open/truncate, to protect tailpacking logics. i_mutex use was wrong and resulted in deadlocks. Signed-off-by: Al Viro --- fs/reiserfs/file.c | 50 ++++++++++++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 22 deletions(-) (limited to 'fs/reiserfs/file.c') diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c index b82cdd8a45d..6846371498b 100644 --- a/fs/reiserfs/file.c +++ b/fs/reiserfs/file.c @@ -38,20 +38,24 @@ static int reiserfs_file_release(struct inode *inode, struct file *filp) BUG_ON(!S_ISREG(inode->i_mode)); + if (atomic_add_unless(&REISERFS_I(inode)->openers, -1, 1)) + return 0; + + mutex_lock(&(REISERFS_I(inode)->tailpack)); + + if (!atomic_dec_and_test(&REISERFS_I(inode)->openers)) { + mutex_unlock(&(REISERFS_I(inode)->tailpack)); + return 0; + } + /* fast out for when nothing needs to be done */ - if ((atomic_read(&inode->i_count) > 1 || - !(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) || + if ((!(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) || !tail_has_to_be_packed(inode)) && REISERFS_I(inode)->i_prealloc_count <= 0) { + mutex_unlock(&(REISERFS_I(inode)->tailpack)); return 0; } - mutex_lock(&inode->i_mutex); - - mutex_lock(&(REISERFS_I(inode)->i_mmap)); - if (REISERFS_I(inode)->i_flags & i_ever_mapped) - REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask; - reiserfs_write_lock(inode->i_sb); /* freeing preallocation only involves relogging blocks that * are already in the current transaction. preallocation gets @@ -94,9 +98,10 @@ static int reiserfs_file_release(struct inode *inode, struct file *filp) if (!err) err = jbegin_failure; - if (!err && atomic_read(&inode->i_count) <= 1 && + if (!err && (REISERFS_I(inode)->i_flags & i_pack_on_close_mask) && tail_has_to_be_packed(inode)) { + /* if regular file is released by last holder and it has been appended (we append by unformatted node only) or its direct item(s) had to be converted, then it may have to be @@ -104,27 +109,28 @@ static int reiserfs_file_release(struct inode *inode, struct file *filp) err = reiserfs_truncate_file(inode, 0); } out: - mutex_unlock(&(REISERFS_I(inode)->i_mmap)); - mutex_unlock(&inode->i_mutex); reiserfs_write_unlock(inode->i_sb); + mutex_unlock(&(REISERFS_I(inode)->tailpack)); return err; } -static int reiserfs_file_mmap(struct file *file, struct vm_area_struct *vma) +static int reiserfs_file_open(struct inode *inode, struct file *file) { - struct inode *inode; - - inode = file->f_path.dentry->d_inode; - mutex_lock(&(REISERFS_I(inode)->i_mmap)); - REISERFS_I(inode)->i_flags |= i_ever_mapped; - mutex_unlock(&(REISERFS_I(inode)->i_mmap)); - - return generic_file_mmap(file, vma); + int err = dquot_file_open(inode, file); + if (!atomic_inc_not_zero(&REISERFS_I(inode)->openers)) { + /* somebody might be tailpacking on final close; wait for it */ + mutex_lock(&(REISERFS_I(inode)->tailpack)); + atomic_inc(&REISERFS_I(inode)->openers); + mutex_unlock(&(REISERFS_I(inode)->tailpack)); + } + return err; } static void reiserfs_vfs_truncate_file(struct inode *inode) { + mutex_lock(&(REISERFS_I(inode)->tailpack)); reiserfs_truncate_file(inode, 1); + mutex_unlock(&(REISERFS_I(inode)->tailpack)); } /* Sync a reiserfs file. */ @@ -288,8 +294,8 @@ const struct file_operations reiserfs_file_operations = { #ifdef CONFIG_COMPAT .compat_ioctl = reiserfs_compat_ioctl, #endif - .mmap = reiserfs_file_mmap, - .open = dquot_file_open, + .mmap = generic_file_mmap, + .open = reiserfs_file_open, .release = reiserfs_file_release, .fsync = reiserfs_sync_file, .aio_read = generic_file_aio_read, -- cgit v1.2.3