From 1b9e7ee3ccdff7c6ef3970461ffaa9a7c0218135 Mon Sep 17 00:00:00 2001 From: Rachita Kothiyal Date: Sun, 25 Nov 2007 17:55:36 -0500 Subject: [PATCH] Unionfs: release lower resources on successful rmdir This patch prevents those resources from lingering around until memory pressure would have forced them out. The patch also properly handles directories that have been rmdir'ed which are still some process's cwd. CC: Hugh Dickins Signed-off-by: Erez Zadok Conflicts: fs/unionfs/unlink.c --- fs/unionfs/inode.c | 3 ++- fs/unionfs/mmap.c | 5 ++++- fs/unionfs/unlink.c | 25 +++++++++++++++++++++++-- 3 files changed, 29 insertions(+), 4 deletions(-) diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c index c646c80f67..149f703274 100644 --- a/fs/unionfs/inode.c +++ b/fs/unionfs/inode.c @@ -764,7 +764,8 @@ static int unionfs_permission(struct inode *inode, int mask, * dentry+inode. This should be equivalent to issuing * __unionfs_d_revalidate_chain on nd.dentry here. */ - err = -ESTALE; /* force revalidate */ + if (is_file) /* dirs can be unlinked but chdir'ed to */ + err = -ESTALE; /* force revalidate */ goto out; } diff --git a/fs/unionfs/mmap.c b/fs/unionfs/mmap.c index 1e10280a76..3f65e524f0 100644 --- a/fs/unionfs/mmap.c +++ b/fs/unionfs/mmap.c @@ -123,8 +123,11 @@ static int unionfs_writepages(struct address_space *mapping, struct inode *inode; inode = mapping->host; + if (ibstart(inode) < 0 && ibend(inode) < 0) + goto out; lower_inode = unionfs_lower_inode(inode); - BUG_ON(!lower_inode); + if (!lower_inode) + goto out; if (!mapping_cap_writeback_dirty(lower_inode->i_mapping)) goto out; diff --git a/fs/unionfs/unlink.c b/fs/unionfs/unlink.c index f2b43f0547..8bad9bce7c 100644 --- a/fs/unionfs/unlink.c +++ b/fs/unionfs/unlink.c @@ -228,6 +228,7 @@ int unionfs_rmdir(struct inode *dir, struct dentry *dentry) { int err = 0; struct unionfs_dir_state *namelist = NULL; + int dstart, dend; unionfs_read_lock(dentry->d_sb); unionfs_lock_dentry(dentry); @@ -250,9 +251,29 @@ int unionfs_rmdir(struct inode *dir, struct dentry *dentry) err = odf_remove(dentry, ODF_RMV_NOTWH); out: - /* call d_drop so the system "forgets" about us */ - if (!err) + /* + * Drop references to lower dentry/inode so storage space for them + * can be reclaimed. Then, call d_drop so the system "forgets" + * about us. + */ + if (!err) { + struct inode *inode = dentry->d_inode; + BUG_ON(!inode); + iput(unionfs_lower_inode_idx(inode, dstart)); + unionfs_set_lower_inode_idx(inode, dstart, NULL); + dput(unionfs_lower_dentry_idx(dentry, dstart)); + unionfs_set_lower_dentry_idx(dentry, dstart, NULL); + /* + * If the last directory is unlinked, then mark istart/end + * as -1, (to maintain the invariant that if there are no + * lower objects, then branch index start and end are set to + * -1). + */ + if (!unionfs_lower_inode_idx(inode, dstart) && + !unionfs_lower_inode_idx(inode, dend)) + ibstart(inode) = ibend(inode) = -1; d_drop(dentry); + } if (namelist) free_rdstate(namelist); -- 2.43.0