On Thu 22-04-10 08:31:11, Dmitry Monakhov wrote: > If i_data_sem was internally dropped due to transaction restart, it is > necessary to restart path look-up because extents tree was possibly > modified by ext4_get_block(). > > https://bugzilla.kernel.org/show_bug.cgi?id=15827 Nice spotting. The patch looks good to me. Acked-by: Jan Kara <jack@xxxxxxx> Honza > > Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> > --- > fs/ext4/ext4.h | 1 + > fs/ext4/extents.c | 18 +++++++++++++----- > 2 files changed, 14 insertions(+), 5 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 6641c58..c69efb2 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1089,6 +1089,7 @@ enum { > EXT4_STATE_DA_ALLOC_CLOSE, /* Alloc DA blks on close */ > EXT4_STATE_EXT_MIGRATE, /* Inode is migrating */ > EXT4_STATE_DIO_UNWRITTEN, /* need convert on dio done*/ > + EXT4_STATE_EXT_TRUNC, /* truncate is in progress, modified under i_data_sem */ > }; > > #define EXT4_INODE_BIT_FNS(name, field) \ > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index 4fa103c..6856272 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -107,11 +107,8 @@ static int ext4_ext_truncate_extend_restart(handle_t *handle, > if (err <= 0) > return err; > err = ext4_truncate_restart_trans(handle, inode, needed); > - /* > - * We have dropped i_data_sem so someone might have cached again > - * an extent we are going to truncate. > - */ > - ext4_ext_invalidate_cache(inode); > + if (!err && !ext4_test_inode_state(inode, EXT4_STATE_EXT_TRUNC)) > + err = -EAGAIN; > > return err; > } > @@ -2370,12 +2367,15 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) > if (IS_ERR(handle)) > return PTR_ERR(handle); > > +again: > ext4_ext_invalidate_cache(inode); > > /* > * We start scanning from right side, freeing all the blocks > * after i_size and walking into the tree depth-wise. > */ > + ext4_set_inode_state(inode, EXT4_STATE_EXT_TRUNC); > + depth = ext_depth(inode); > path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS); > if (path == NULL) { > ext4_journal_stop(handle); > @@ -2480,6 +2480,11 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) > out: > ext4_ext_drop_refs(path); > kfree(path); > + if (err == EAGAIN) { > + err = 0; > + goto again; > + } > + ext4_clear_inode_state(inode, EXT4_STATE_EXT_TRUNC); > ext4_journal_stop(handle); > > return err; > @@ -3338,6 +3343,9 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, > ext_debug("blocks %u/%u requested for inode %lu\n", > iblock, max_blocks, inode->i_ino); > > + if (unlikely((flags & EXT4_GET_BLOCKS_CREATE)) && > + ext4_test_inode_state(inode, EXT4_STATE_EXT_TRUNC)) > + ext4_clear_inode_state(inode, EXT4_STATE_EXT_TRUNC); > /* check in cache */ > cache_type = ext4_ext_in_cache(inode, iblock, &newex); > if (cache_type) { > -- > 1.6.6.1 > -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
