Hi Jaegeuk, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] > Sent: Thursday, April 16, 2015 3:31 PM > To: linux-kernel@xxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: Jaegeuk Kim > Subject: [f2fs-dev] [PATCH 1/3] f2fs: flush symlink path to avoid broken symlink after POR > > This patch tries to avoid broken symlink case after POR in best effort. > This results in performance regression. > But, if f2fs has inline_data and the target path is under 3KB-sized long, > the page would be stored in its inode_block, so that there would be no > performance regression. > > Note that, if user wants to keep this file atomically, it needs to trigger > dir->fsync. > And, there is still a hole to produce broken symlink. > > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > --- > fs/f2fs/namei.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c > index 8055e30..5d990d8 100644 > --- a/fs/f2fs/namei.c > +++ b/fs/f2fs/namei.c > @@ -324,6 +324,17 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry, > d_instantiate(dentry, inode); > unlock_new_inode(inode); > > + /* > + * Let's flush symlink data in order to avoid broken symlink as much as > + * possible. Nevertheless, fsyncing is the best way, but there is no > + * way to get a file descriptor in order to flush that. > + * > + * Note that, it needs to do dir->fsync to make this recoverable. > + * If the symlink path is stored into inline_data, there is no > + * performance regression. > + */ > + filemap_write_and_wait_range(inode->i_mapping, 0, symlen); One minor thing. filemap_write_and_wait_range(inode->i_mapping, 0, symlen - 1); Because we don't need to write out data exceed isize here. Thanks, > + > if (IS_DIRSYNC(dir)) > f2fs_sync_fs(sbi->sb, 1); > return err; > -- > 2.1.1 > > > ------------------------------------------------------------------------------ > BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT > Develop your own process in accordance with the BPMN 2 standard > Learn Process modeling best practices with Bonita BPM through live exercises > http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ > source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
