Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932377AbaAHWKr (ORCPT ); Wed, 8 Jan 2014 17:10:47 -0500 Received: from mail-ee0-f45.google.com ([74.125.83.45]:37797 "EHLO mail-ee0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932307AbaAHWKB (ORCPT ); Wed, 8 Jan 2014 17:10:01 -0500 From: Miklos Szeredi To: viro@ZenIV.linux.org.uk Cc: torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, dhowells@redhat.com, zab@redhat.com, jack@suse.cz, luto@amacapital.net, mszeredi@suse.cz Subject: [PATCH 11/11] ext4: add cross rename support Date: Wed, 8 Jan 2014 23:10:15 +0100 Message-Id: <1389219015-10980-12-git-send-email-miklos@szeredi.hu> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1389219015-10980-1-git-send-email-miklos@szeredi.hu> References: <1389219015-10980-1-git-send-email-miklos@szeredi.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Miklos Szeredi Implement RENAME_EXCHANGE flag in renameat2 syscall. Signed-off-by: Miklos Szeredi --- fs/ext4/namei.c | 121 ++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 87 insertions(+), 34 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 7147d08a43a2..e4513ba7ed99 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3005,6 +3005,8 @@ struct ext4_renament { struct inode *dir; struct dentry *dentry; struct inode *inode; + bool is_dir; + int dir_nlink_delta; /* entry for "dentry" */ struct buffer_head *bh; @@ -3136,6 +3138,14 @@ static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent) } } +static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) +{ + if (ent->dir_nlink_delta == -1) + ext4_dec_count(handle, ent->dir); + else if (ent->dir_nlink_delta == 1) + ext4_inc_count(handle, ent->dir); +} + /* * Anybody can rename anything with this: the permission checks are left to the * higher-level routines. @@ -3161,7 +3171,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, }; int retval; - if (flags & ~RENAME_NOREPLACE) + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) return -EOPNOTSUPP; dquot_initialize(old.dir); @@ -3169,10 +3179,11 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, /* Initialize quotas before so that eventual writes go * in separate transaction */ - if (new.inode) + if (!(flags & RENAME_EXCHANGE) && new.inode) dquot_initialize(new.inode); - old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); + old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, + &old.de, &old.inlined); /* * Check for inode number is _not_ due to possible IO errors. * We might rmdir the source, keep it as pwd of some process @@ -3185,18 +3196,22 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, &new.de, &new.inlined); - if (new.bh) { - if (!new.inode) { - brelse(new.bh); - new.bh = NULL; + if (!(flags & RENAME_EXCHANGE)) { + if (new.bh) { + if (!new.inode) { + brelse(new.bh); + new.bh = NULL; + } } + if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) + ext4_alloc_da_blocks(old.inode); + } else if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) { + goto end_rename; } - if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) - ext4_alloc_da_blocks(old.inode); handle = ext4_journal_start(old.dir, EXT4_HT_DIR, (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + - EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); + 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); if (IS_ERR(handle)) return PTR_ERR(handle); @@ -3204,28 +3219,61 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, ext4_handle_sync(handle); if (S_ISDIR(old.inode->i_mode)) { - if (new.inode) { + old.is_dir = true; + if (!(flags & RENAME_EXCHANGE) && new.inode) { retval = -ENOTEMPTY; if (!empty_dir(new.inode)) goto end_rename; - } else { - retval = -EMLINK; - if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) - goto end_rename; + + /* + * Overwriting a directory needs to decrement nlink of + * old parent (even if not cross directory rename). + */ + old.dir_nlink_delta = -1; } retval = ext4_rename_dir_prepare(handle, &old); if (retval) goto end_rename; } + if (new.inode && S_ISDIR(new.inode->i_mode)) { + new.is_dir = true; + if (flags & RENAME_EXCHANGE) { + retval = ext4_rename_dir_prepare(handle, &new); + if (retval) + goto end_rename; + } + } + + /* + * Other than the special case of overwring a directory, parents' nlink + * only needs to be modified if this is a cross directory rename. + */ + if (old.dir != new.dir && old.is_dir != new.is_dir) { + old.dir_nlink_delta = old.is_dir ? -1 : 1; + new.dir_nlink_delta = -old.dir_nlink_delta; + retval = -EMLINK; + if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || + (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) + goto end_rename; + } + if (!new.bh) { retval = ext4_add_entry(handle, new.dentry, old.inode); if (retval) goto end_rename; } else { + u8 new_file_type = new.de->file_type; retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); if (retval) goto end_rename; + + if (flags & RENAME_EXCHANGE) { + retval = ext4_setent(handle, &old, + new.inode->i_ino, new_file_type); + if (retval) + goto end_rename; + } } /* @@ -3235,35 +3283,40 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, old.inode->i_ctime = ext4_current_time(old.inode); ext4_mark_inode_dirty(handle, old.inode); - /* - * ok, that's it - */ - ext4_rename_delete(handle, &old); + if (!(flags & RENAME_EXCHANGE)) { + /* + * ok, that's it + */ + ext4_rename_delete(handle, &old); - if (new.inode) { - ext4_dec_count(handle, new.inode); - new.inode->i_ctime = ext4_current_time(new.inode); + old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir); + ext4_update_dx_flag(old.dir); } - old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir); - ext4_update_dx_flag(old.dir); if (old.dir_bh) { retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); if (retval) goto end_rename; - - ext4_dec_count(handle, old.dir); - if (new.inode) { + } + if (new.dir_bh) { + retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); + if (retval) + goto end_rename; + } + ext4_update_dir_count(handle, &old); + ext4_update_dir_count(handle, &new); + if (!new.inode) + ext4_update_dx_flag(new.dir); + if (new.dir_nlink_delta || !new.inode) + ext4_mark_inode_dirty(handle, new.dir); + ext4_mark_inode_dirty(handle, old.dir); + if (!(flags & RENAME_EXCHANGE) && new.inode) { + ext4_dec_count(handle, new.inode); + new.inode->i_ctime = ext4_current_time(new.inode); + if (S_ISDIR(old.inode->i_mode)) { /* checked empty_dir above, can't have another parent, * ext4_dec_count() won't work for many-linked dirs */ clear_nlink(new.inode); - } else { - ext4_inc_count(handle, new.dir); - ext4_update_dx_flag(new.dir); - ext4_mark_inode_dirty(handle, new.dir); } - } - ext4_mark_inode_dirty(handle, old.dir); - if (new.inode) { ext4_mark_inode_dirty(handle, new.inode); if (!new.inode->i_nlink) ext4_orphan_add(handle, new.inode); -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/