Hi Chao, On Thu, Jul 16, 2015 at 06:03:46PM +0800, Chao Yu wrote: > Hi Jaegeuk, > > > -----Original Message----- > > From: Jaegeuk Kim [mailto:[email protected]] > > Sent: Thursday, July 16, 2015 6:38 AM > > To: [email protected]; [email protected]; > > [email protected] > > Cc: Jaegeuk Kim > > Subject: [f2fs-dev] [PATCH 3/3] f2fs: allow zeroed name length during > > find_dentry > > > > Since find_dentry doesn't lock its dentry page, it can traverse intermediate > > bit positions consisting of a big dentry. > > For these bit positions, this patch fills the intermediate name length > > fields > > as zeros and skips them during look-up. > > I didn't get it, AFAIK, dentry page will be accessed under protection of > i_mutex, if our inode operation has no bug, why this zeroed name_len can > exist?
Indeed. I've checked that again, and i_mutex covers this. I'll drop this patch, and let me keep an eye on any further bug report about this. :) Thanks, > > Thanks, > > > > > Signed-off-by: Jaegeuk Kim <[email protected]> > > --- > > fs/f2fs/dir.c | 20 ++++++++++++++------ > > 1 file changed, 14 insertions(+), 6 deletions(-) > > > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > > index a34ebd8..71195f5 100644 > > --- a/fs/f2fs/dir.c > > +++ b/fs/f2fs/dir.c > > @@ -141,11 +141,15 @@ struct f2fs_dir_entry *find_target_dentry(struct > > f2fs_filename *fname, > > *max_slots = max_len; > > max_len = 0; > > > > - /* remain bug on condition */ > > - if (unlikely(!de->name_len)) > > - d->max = -1; > > - > > - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); > > + /* > > + * While a large dentry is adding, it can traverse its valid bit > > + * positions, since find_entry does not lock its dentry page. > > + * In that case, let's skip the bit position. > > + */ > > + if (de_name.len == 0) > > + bit_pos++; > > + else > > + bit_pos += GET_DENTRY_SLOTS(de_name.len); > > } > > > > de = NULL; > > @@ -505,8 +509,12 @@ void f2fs_update_dentry(nid_t ino, umode_t mode, > > struct f2fs_dentry_ptr > > *d, > > memcpy(d->filename[bit_pos], name->name, name->len); > > de->ino = cpu_to_le32(ino); > > set_de_type(de, mode); > > - for (i = 0; i < slots; i++) > > + for (i = 0; i < slots; i++) { > > + /* fill zeros for intermediate name_len slots */ > > + if (i >= 1) > > + d->dentry[bit_pos + i].name_len = 0; > > test_and_set_bit_le(bit_pos + i, (void *)d->bitmap); > > + } > > } > > > > /* > > -- > > 2.1.1 > > > > > > ------------------------------------------------------------------------------ > > Don't Limit Your Business. Reach for the Cloud. > > GigeNET's Cloud Solutions provide you with the tools and support that > > you need to offload your IT needs and focus on growing your business. > > Configured For All Businesses. Start Your Cloud Today. > > https://www.gigenetcloud.com/ > > _______________________________________________ > > Linux-f2fs-devel mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
