A few tool developers gave me requests for fixing inconvenient return value of nilfs_get_cpinfo() ioctl; if the requested mode is NILFS_SNAPSHOT and the specified start entry is not a snapshot, the ioctl unnaturally returns one as the number of acquired snapshot item. In addition, the ioctl function returns an ENOENT error for checkpoints within blocks deleted by garbage collection. These behaviors require corrections for programs which enumerate snapshots. This resolves the inconvenience by changing the return values to zero for the above cases. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx> --- fs/nilfs2/cpfile.c | 30 ++++++++++++++++++------------ 1 files changed, 18 insertions(+), 12 deletions(-) diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c index 2e3b066..e90b60d 100644 --- a/fs/nilfs2/cpfile.c +++ b/fs/nilfs2/cpfile.c @@ -434,7 +434,7 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, __u64 curr = *cnop, next; unsigned long curr_blkoff, next_blkoff; void *kaddr; - int n, ret; + int n = 0, ret; down_read(&NILFS_MDT(cpfile)->mi_sem); @@ -458,27 +458,33 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr); ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh); - if (ret < 0) + if (unlikely(ret < 0)) { + if (ret == -ENOENT) + ret = 0; /* No snapshots (started from a hole block) */ goto out; + } kaddr = kmap_atomic(bh->b_page, KM_USER0); - for (n = 0; n < nci; n++) { - cp = nilfs_cpfile_block_get_checkpoint( - cpfile, curr, bh, kaddr); - nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n]); - next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); - if (next == 0) { - curr = ~(__u64)0; /* Terminator */ - n++; + while (n < nci) { + cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr); + curr = ~(__u64)0; /* Terminator */ + if (unlikely(nilfs_checkpoint_invalid(cp) || + !nilfs_checkpoint_snapshot(cp))) break; - } + nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n++]); + next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); + if (next == 0) + break; /* reach end of the snapshot list */ + next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next); if (curr_blkoff != next_blkoff) { kunmap_atomic(kaddr, KM_USER0); brelse(bh); ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0, &bh); - if (ret < 0) + if (unlikely(ret < 0)) { + WARN_ON(ret == -ENOENT); goto out; + } kaddr = kmap_atomic(bh->b_page, KM_USER0); } curr = next; -- 1.5.6.5 -- 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