diff options
| -rw-r--r-- | mm/shmem.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index cd6fc7590e54..185836ba53ef 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2345,6 +2345,32 @@ static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, stru return 0; } +static int shmem_whiteout(struct inode *old_dir, struct dentry *old_dentry) +{ + struct dentry *whiteout; + int error; + + whiteout = d_alloc(old_dentry->d_parent, &old_dentry->d_name); + if (!whiteout) + return -ENOMEM; + + error = shmem_mknod(old_dir, whiteout, + S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); + dput(whiteout); + if (error) + return error; + + /* + * Cheat and hash the whiteout while the old dentry is still in + * place, instead of playing games with FS_RENAME_DOES_D_MOVE. + * + * d_lookup() will consistently find one of them at this point, + * not sure which one, but that isn't even important. + */ + d_rehash(whiteout); + return 0; +} + /* * The VFS layer already does all the dentry stuff for rename, * we just have to decrement the usage count for the target if @@ -2356,7 +2382,7 @@ static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struc struct inode *inode = old_dentry->d_inode; int they_are_dirs = S_ISDIR(inode->i_mode); - if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) return -EINVAL; if (flags & RENAME_EXCHANGE) @@ -2365,6 +2391,14 @@ static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struc if (!simple_empty(new_dentry)) return -ENOTEMPTY; + if (flags & RENAME_WHITEOUT) { + int error; + + error = shmem_whiteout(old_dir, old_dentry); + if (error) + return error; + } + if (new_dentry->d_inode) { (void) shmem_unlink(new_dir, new_dentry); if (they_are_dirs) { |