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| author | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-08-15 18:33:57 +0400 |
|---|---|---|
| committer | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-10-23 04:24:35 +0400 |
| commit | dc3d3b810a644dfa329efaa230cd514226f8981d (patch) | |
| tree | e0a2c2bfb3edb6b1fa4383cb2d1f52adb653c9e2 /fs/nilfs2/inode.c | |
| parent | fd52202930b7e8db48bee5a6fc6b1f438e822a23 (diff) | |
| download | linux-dc3d3b810a644dfa329efaa230cd514226f8981d.tar.xz | |
nilfs2: deny write access to inodes in snapshots
Snapshots of nilfs are read-only.
After super block instances (sb) will be unified, nilfs will need to
check write access by a way other than implicit test with
IS_RDONLY(inode). This is because IS_RDONLY() refers to MS_RDONLY bit
of inode->i_sb->s_flags and it will become inaccurate after the
unification of sb.
To prepare for the issue, this uses i_op->permission to deny write
access to inodes in snapshots.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2/inode.c')
| -rw-r--r-- | fs/nilfs2/inode.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index ca09e4362d66..3efef0ecfa24 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -764,6 +764,17 @@ out_err: return err; } +int nilfs_permission(struct inode *inode, int mask) +{ + struct nilfs_root *root = NILFS_I(inode)->i_root; + + if ((mask & MAY_WRITE) && root && + root->cno != NILFS_CPTREE_CURRENT_CNO) + return -EROFS; /* snapshot is not writable */ + + return generic_permission(inode, mask, NULL); +} + int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode, struct buffer_head **pbh) { |