From b028fcfc4cd198a6aa1ffcfb872073ccc1db3459 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 6 Apr 2009 19:01:47 -0700 Subject: nilfs2: fix gc failure on volumes keeping numerous snapshots This resolves the following failure of nilfs2 cleaner daemon: nilfs_cleanerd[20670]: cannot clean segments: No such file or directory nilfs_cleanerd[20670]: shutdown When creating thousands of snapshots, the cleaner daemon had rarely died as above due to an error returned from the kernel code. After applying the recent patch which fixed memory allocation problems in ioctl (Message-Id: <20081215.155840.105124170.ryusuke@osrg.net>), the problem gets more frequent. It turned out to be a bug of nilfs_ioctl_wrap_copy function and one of its callback routines to read out information of snapshots; if the nilfs_ioctl_wrap_copy function divided a large read request into multiple requests, the second and later requests have failed since a restart position on snapshot meta data was not properly set forward. It's a deficiency of the callback interface that cannot pass the restart position among multiple requests. This patch fixes the issue by allowing nilfs_ioctl_wrap_copy and snapshot read functions to exchange a position argument. Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/cpfile.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'fs/nilfs2/cpfile.c') diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c index 82462acd06e..a4c9550fd77 100644 --- a/fs/nilfs2/cpfile.c +++ b/fs/nilfs2/cpfile.c @@ -422,20 +422,20 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 cno, return ret; } -static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 cno, +static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, struct nilfs_cpinfo *ci, size_t nci) { struct buffer_head *bh; struct nilfs_cpfile_header *header; struct nilfs_checkpoint *cp; - __u64 curr, next; + __u64 curr = *cnop, next; unsigned long curr_blkoff, next_blkoff; void *kaddr; int n, ret; down_read(&NILFS_MDT(cpfile)->mi_sem); - if (cno == 0) { + if (curr == 0) { ret = nilfs_cpfile_get_header_block(cpfile, &bh); if (ret < 0) goto out; @@ -448,8 +448,11 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 cno, ret = 0; goto out; } - } else - curr = cno; + } else if (unlikely(curr == ~(__u64)0)) { + ret = 0; + goto out; + } + curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr); ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh); if (ret < 0) @@ -461,7 +464,7 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 cno, nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n]); next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); if (next == 0) { - curr = next; + curr = ~(__u64)0; /* Terminator */ n++; break; } @@ -480,6 +483,7 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 cno, } kunmap_atomic(kaddr, KM_USER0); brelse(bh); + *cnop = curr; ret = n; out: @@ -494,15 +498,15 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 cno, * @ci: * @nci: */ -ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, - __u64 cno, int mode, + +ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode, struct nilfs_cpinfo *ci, size_t nci) { switch (mode) { case NILFS_CHECKPOINT: - return nilfs_cpfile_do_get_cpinfo(cpfile, cno, ci, nci); + return nilfs_cpfile_do_get_cpinfo(cpfile, *cnop, ci, nci); case NILFS_SNAPSHOT: - return nilfs_cpfile_do_get_ssinfo(cpfile, cno, ci, nci); + return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, ci, nci); default: return -EINVAL; } -- cgit v1.2.3-18-g5258