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| author | Jan Kara | 2012-06-12 16:20:38 +0200 |
|---|---|---|
| committer | Al Viro | 2012-07-31 07:45:48 +0200 |
| commit | 8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275 (patch) | |
| tree | 8d1fd1d0f296d2a2977b54dee5740d855dfa031e /fs/ext4/inode.c | |
| parent | fs: Protect write paths by sb_start_write - sb_end_write (diff) | |
| download | kernel-qcow2-linux-8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275.tar.gz kernel-qcow2-linux-8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275.tar.xz kernel-qcow2-linux-8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275.zip | |
ext4: Convert to new freezing mechanism
We remove most of frozen checks since upper layer takes care of blocking all
writes. We have to handle protection in ext4_page_mkwrite() in a special way
because we cannot use generic block_page_mkwrite(). Also we add a freeze
protection to ext4_evict_inode() so that iput() of unlinked inode cannot modify
a frozen filesystem (we cannot easily instrument ext4_journal_start() /
ext4_journal_stop() with freeze protection because we are missing the
superblock pointer in ext4_journal_stop() in nojournal mode).
CC: linux-ext4@vger.kernel.org
CC: "Theodore Ts'o" <tytso@mit.edu>
BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/ext4/inode.c')
| -rw-r--r-- | fs/ext4/inode.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 02bc8cbe7281..301e1c2db891 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -233,6 +233,11 @@ void ext4_evict_inode(struct inode *inode) if (is_bad_inode(inode)) goto no_delete; + /* + * Protect us against freezing - iput() caller didn't have to have any + * protection against it + */ + sb_start_intwrite(inode->i_sb); handle = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)+3); if (IS_ERR(handle)) { ext4_std_error(inode->i_sb, PTR_ERR(handle)); @@ -242,6 +247,7 @@ void ext4_evict_inode(struct inode *inode) * cleaned up. */ ext4_orphan_del(NULL, inode); + sb_end_intwrite(inode->i_sb); goto no_delete; } @@ -273,6 +279,7 @@ void ext4_evict_inode(struct inode *inode) stop_handle: ext4_journal_stop(handle); ext4_orphan_del(NULL, inode); + sb_end_intwrite(inode->i_sb); goto no_delete; } } @@ -301,6 +308,7 @@ void ext4_evict_inode(struct inode *inode) else ext4_free_inode(handle, inode); ext4_journal_stop(handle); + sb_end_intwrite(inode->i_sb); return; no_delete: ext4_clear_inode(inode); /* We must guarantee clearing of inode... */ @@ -4701,11 +4709,7 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) get_block_t *get_block; int retries = 0; - /* - * This check is racy but catches the common case. We rely on - * __block_page_mkwrite() to do a reliable check. - */ - vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); + sb_start_pagefault(inode->i_sb); /* Delalloc case is easy... */ if (test_opt(inode->i_sb, DELALLOC) && !ext4_should_journal_data(inode) && @@ -4773,5 +4777,6 @@ retry_alloc: out_ret: ret = block_page_mkwrite_return(ret); out: + sb_end_pagefault(inode->i_sb); return ret; } |