From 7fa10d20012296300dfe645cb3e628a4e9a0d5ef Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 6 Apr 2009 19:01:48 -0700 Subject: [PATCH] nilfs2: fix improper return values of nilfs_get_cpinfo ioctl 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/cpfile.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c index a4c9550fd77..50dff147744 100644 --- a/fs/nilfs2/cpfile.c +++ b/fs/nilfs2/cpfile.c @@ -431,7 +431,7 @@ 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); @@ -455,27 +455,33 @@ 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; -- 2.41.0