Hi, 2013-10-28 (월), 08:15 +0000, Shifei Ge: > truncate_partial_nodes puts pages incorrectly in two cases.note that the > value for argc 'depth' can only be 2 or 3(see truncate_inode_blocks > --->truncate_partial_nodes ). > first case:err happened in the first 'for' loop > assume depth is 2,when err happened,pages[0] is invalid,so this page > don't need to be put when func return,there is no problem. > but when depth is 3 ,pages isn't put correctly when pages[0] is valid > and pages[1] is invalid.in this case,depth is set to 2(ref to statemnt depth > = i + 1) ,and then 'goto fail'. > in label 'fail', for (i = depth - 3; i >= 0; i--) cann't meet the > condition because i=-1,so pages[0] cann't be put when func return. > second case:err happened in the second 'for' loop > now,we've got pages[0] with argc 'depth' is 2 ,or we've got pages[0] > and pages[1] with depth is 3.when err happend,we need 'goto fail' to put > pages we've got. > when depth is 2,in label 'fail',for (i = depth - 3; i >= 0; i--) cann't > meet the condition because i=-1,so pages[0] cann't be put. > when depth is 3,in label 'fail',for (i = depth - 3; i >= 0; i--) can > only put pages[0],pages[1] also cann't be put. > notes 'depth' has been changed before first 'goto fail'(ref to statemnt depth > = i + 1),so pass this modified 'depth' to trace_f2fs_truncate_partial_nodes > is also incorrectly.
Please write a description not to exceed 80 columns. It's very hard to understand. > > From 9de8efa31759ce86a032f5ad092d337b686ede06 Mon Sep 17 00:00:00 2001 > Signed-off-by: Shifei Ge <[email protected]> > --- > fs/f2fs/node.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index 304d5ce..9986930 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -625,6 +625,7 @@ static int truncate_partial_nodes(struct dnode_of_data > *dn, > int err = 0; > int i; > int idx = depth - 2; > + int dep = depth; I think we need to avoid using a local variable only for the use of tracepoints below. How about this? --- fs/f2fs/node.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 304d5ce..8578719 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -631,11 +631,10 @@ static int truncate_partial_nodes(struct dnode_of_data *dn, return 0; /* get indirect nodes in the path */ - for (i = 0; i < depth - 1; i++) { + for (i = 0; i < idx + 1; i++) { /* refernece count'll be increased */ pages[i] = get_node_page(sbi, nid[i]); if (IS_ERR(pages[i])) { - depth = i + 1; err = PTR_ERR(pages[i]); goto fail; } @@ -643,7 +642,7 @@ static int truncate_partial_nodes(struct dnode_of_data *dn, } /* free direct nodes linked to a partial indirect node */ - for (i = offset[depth - 1]; i < NIDS_PER_BLOCK; i++) { + for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) { child_nid = get_nid(pages[idx], i, false); if (!child_nid) continue; @@ -654,7 +653,7 @@ static int truncate_partial_nodes(struct dnode_of_data *dn, set_nid(pages[idx], i, 0, false); } - if (offset[depth - 1] == 0) { + if (offset[idx + 1] == 0) { dn->node_page = pages[idx]; dn->nid = nid[idx]; truncate_node(dn); @@ -662,9 +661,10 @@ static int truncate_partial_nodes(struct dnode_of_data *dn, f2fs_put_page(pages[idx], 1); } offset[idx]++; - offset[depth - 1] = 0; + offset[idx + 1] = 0; + idx--; fail: - for (i = depth - 3; i >= 0; i--) + for (i = idx; i >= 0; i--) f2fs_put_page(pages[i], 1); trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err); -- 1.8.4.474.g128a96c -- Jaegeuk Kim Samsung -- 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/
