From: Theodore Ts'o Subject: [PATCH 21/42] ext4: elevate write count for migrate ioctl Date: Thu, 9 Oct 2008 00:05:39 -0400 Message-ID: <1223525160-9887-22-git-send-email-tytso@mit.edu> References: <1223525160-9887-1-git-send-email-tytso@mit.edu> <1223525160-9887-2-git-send-email-tytso@mit.edu> <1223525160-9887-3-git-send-email-tytso@mit.edu> <1223525160-9887-4-git-send-email-tytso@mit.edu> <1223525160-9887-5-git-send-email-tytso@mit.edu> <1223525160-9887-6-git-send-email-tytso@mit.edu> <1223525160-9887-7-git-send-email-tytso@mit.edu> <1223525160-9887-8-git-send-email-tytso@mit.edu> <1223525160-9887-9-git-send-email-tytso@mit.edu> <1223525160-9887-10-git-send-email-tytso@mit.edu> <1223525160-9887-11-git-send-email-tytso@mit.edu> <1223525160-9887-12-git-send-email-tytso@mit.edu> <1223525160-9887-13-git-send-email-tytso@mit.edu> <1223525160-9887-14-git-send-email-tytso@mit.edu> <1223525160-9887-15-git-send-email-tytso@mit.edu> <1223525160-9887-16-git-send-email-tytso@mit.edu> <1223525160-9887-17-git-send-email-tytso@mit.edu> <1223525160-9887-18-git-send-email-tytso@mit.edu> <1223525160-9887-19-git-send-email-tytso@mit.edu> <1223525160-9887-20-git-send-email-tytso@mit.edu> <1223525160-9887-21-git-send-email-tytso@mit.edu> Cc: "Aneesh Kumar K.V" , "Theodore Ts'o" To: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:54510 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757598AbYJIEGN (ORCPT ); Thu, 9 Oct 2008 00:06:13 -0400 In-Reply-To: <1223525160-9887-21-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Aneesh Kumar K.V The migrate ioctl writes to the filsystem, so we need to elevate the write count. Signed-off-by: Aneesh Kumar K.V Signed-off-by: "Theodore Ts'o" --- fs/ext4/ext4.h | 3 +-- fs/ext4/ioctl.c | 21 ++++++++++++++++++++- fs/ext4/migrate.c | 10 +--------- 3 files changed, 22 insertions(+), 12 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 3e47b99..9b6ad8f 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1084,8 +1084,7 @@ extern long ext4_ioctl(struct file *, unsigned int, unsigned long); extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long); /* migrate.c */ -extern int ext4_ext_migrate(struct inode *, struct file *, unsigned int, - unsigned long); +extern int ext4_ext_migrate(struct inode *); /* namei.c */ extern int ext4_orphan_add(handle_t *, struct inode *); extern int ext4_orphan_del(handle_t *, struct inode *); diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index ca09dd1..9f3044a 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -267,7 +267,26 @@ setversion_out: } case EXT4_IOC_MIGRATE: - return ext4_ext_migrate(inode, filp, cmd, arg); + { + int err; + if (!is_owner_or_cap(inode)) + return -EACCES; + + err = mnt_want_write(filp->f_path.mnt); + if (err) + return err; + /* + * inode_mutex prevent write and truncate on the file. + * Read still goes through. We take i_data_sem in + * ext4_ext_swap_inode_data before we switch the + * inode format to prevent read. + */ + mutex_lock(&(inode->i_mutex)); + err = ext4_ext_migrate(inode); + mutex_unlock(&(inode->i_mutex)); + mnt_drop_write(filp->f_path.mnt); + return err; + } default: return -ENOTTY; diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c index 46fc0b5..f2a9cf4 100644 --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -447,8 +447,7 @@ static int free_ext_block(handle_t *handle, struct inode *inode) } -int ext4_ext_migrate(struct inode *inode, struct file *filp, - unsigned int cmd, unsigned long arg) +int ext4_ext_migrate(struct inode *inode) { handle_t *handle; int retval = 0, i; @@ -516,12 +515,6 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp, * when we add extents we extent the journal */ /* - * inode_mutex prevent write and truncate on the file. Read still goes - * through. We take i_data_sem in ext4_ext_swap_inode_data before we - * switch the inode format to prevent read. - */ - mutex_lock(&(inode->i_mutex)); - /* * Even though we take i_mutex we can still cause block allocation * via mmap write to holes. If we have allocated new blocks we fail * migrate. New block allocation will clear EXT4_EXT_MIGRATE flag. @@ -623,7 +616,6 @@ err_out: tmp_inode->i_nlink = 0; ext4_journal_stop(handle); - mutex_unlock(&(inode->i_mutex)); if (tmp_inode) iput(tmp_inode); -- 1.5.6.1.205.ge2c7.dirty