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eCryptfs: fix dentry handling on create error, unlink, and inode destroy

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This patch corrects some erroneous dentry handling in eCryptfs.

If there is a problem creating the lower file, then there is nothing that
the persistent lower file can do to really help us.  This patch makes a
vfs_create() failure in the lower filesystem always lead to an
unconditional do_create failure in eCryptfs.

Under certain sequences of operations, the eCryptfs dentry can remain in
the dcache after an unlink.  This patch calls d_drop() on the eCryptfs
dentry to correct this.

eCryptfs has no business calling d_delete() directly on a lower
filesystem's dentry.  This patch removes the call to d_delete() on the
lower persistent file's dentry in ecryptfs_destroy_inode().

(Thanks to David Kleikamp, Eric Sandeen, and Jeff Moyer for helping
identify and resolve this issue)

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Halcrow 2008-01-08 15:33:02 -08:00 committed by Linus Torvalds
parent c51b1a160b
commit caeeeecfda
2 changed files with 4 additions and 17 deletions
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20
fs/ecryptfs/inode.c
View file

@ -120,22 +120,9 @@ ecryptfs_do_create(struct inode *directory_inode,
rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
ecryptfs_dentry, mode, nd);
if (rc) {
struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
struct ecryptfs_inode_info *inode_info =
ecryptfs_inode_to_private(ecryptfs_inode);
printk(KERN_WARNING "%s: Error creating underlying file; "
"rc = [%d]; checking for existing\n", __FUNCTION__, rc);
if (inode_info) {
mutex_lock(&inode_info->lower_file_mutex);
if (!inode_info->lower_file) {
mutex_unlock(&inode_info->lower_file_mutex);
printk(KERN_ERR "%s: Failure to set underlying "
"file; rc = [%d]\n", __FUNCTION__, rc);
goto out_lock;
}
mutex_unlock(&inode_info->lower_file_mutex);
}
printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
"rc = [%d]\n", __FUNCTION__, rc);
goto out_lock;
}
rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
directory_inode->i_sb, 0);
@ -451,6 +438,7 @@ static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
dentry->d_inode->i_nlink =
ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
dentry->d_inode->i_ctime = dir->i_ctime;
d_drop(dentry);
out_unlock:
unlock_parent(lower_dentry);
return rc;

1
fs/ecryptfs/super.c
View file

@ -86,7 +86,6 @@ static void ecryptfs_destroy_inode(struct inode *inode)
fput(inode_info->lower_file);
inode_info->lower_file = NULL;
d_drop(lower_dentry);
d_delete(lower_dentry);
}
}
mutex_unlock(&inode_info->lower_file_mutex);