path: root/fs/gfs2/inode.h
diff options
authorBenjamin Marzinski <bmarzins@redhat.com>2007-09-18 13:33:18 -0500
committerSteven Whitehouse <swhiteho@redhat.com>2007-10-10 08:56:29 +0100
commit7a9f53b3c1875bef22ad4588e818bc046ef183da (patch)
tree0b23b5b8a667d0d57c695c47f6b4eb6d50c2d661 /fs/gfs2/inode.h
parent[GFS2] Data corruption fix (diff)
[GFS2] Alternate gfs2_iget to avoid looking up inodes being freed
There is a possible deadlock between two processes on the same node, where one process is deleting an inode, and another process is looking for allocated but unused inodes to delete in order to create more space. process A does an iput() on inode X, and it's i_count drops to 0. This causes iput_final() to be called, which puts an inode into state I_FREEING at generic_delete_inode(). There no point between when iput_final() is called, and when I_FREEING is set where GFS2 could acquire any glocks. Once I_FREEING is set, no other process on that node can successfully look up that inode until the delete finishes. process B locks the the resource group for the same inode in get_local_rgrp(), which is called by gfs2_inplace_reserve_i() process A tries to lock the resource group for the inode in gfs2_dinode_dealloc(), but it's already locked by process B process B waits in find_inode for the inode to have the I_FREEING state cleared. Deadlock. This patch solves the problem by adding an alternative to gfs2_iget(), gfs2_iget_skip(), that simply skips any inodes that are in the I_FREEING state.o The alternate test function is just like the original one, except that it fails if the inode is being freed, and sets a skipped flag. The alternate set function is just like the original, except that it fails if the skipped flag is set. Only try_rgrp_unlink() calls gfs2_iget_skip() instead of gfs2_iget(). Signed-off-by: Benjamin E. Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/inode.h')
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index 4517ac82c01c..351ac87ab384 100644
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -49,7 +49,8 @@ static inline void gfs2_inum_out(const struct gfs2_inode *ip,
void gfs2_inode_attr_in(struct gfs2_inode *ip);
void gfs2_set_iop(struct inode *inode);
struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned type,
- u64 no_addr, u64 no_formal_ino);
+ u64 no_addr, u64 no_formal_ino,
+ int skip_freeing);
struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr);
int gfs2_inode_refresh(struct gfs2_inode *ip);