diff options
| -rw-r--r-- | fs/xfs/xfs_icache.c | 52 | ||||
| -rw-r--r-- | fs/xfs/xfs_icache.h | 4 |
2 files changed, 54 insertions, 2 deletions
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index 990210fcb9c3..d78c853265d4 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -368,6 +368,11 @@ xfs_iget_cache_hit( if (ip->i_flags & XFS_IRECLAIMABLE) { trace_xfs_iget_reclaim(ip); + if (flags & XFS_IGET_INCORE) { + error = -EAGAIN; + goto out_error; + } + /* * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode * from stomping over us while we recycle the inode. We can't @@ -432,7 +437,8 @@ xfs_iget_cache_hit( if (lock_flags != 0) xfs_ilock(ip, lock_flags); - xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE); + if (!(flags & XFS_IGET_INCORE)) + xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE); XFS_STATS_INC(mp, xs_ig_found); return 0; @@ -603,6 +609,10 @@ again: goto out_error_or_again; } else { rcu_read_unlock(); + if (flags & XFS_IGET_INCORE) { + error = -ENOENT; + goto out_error_or_again; + } XFS_STATS_INC(mp, xs_ig_missed); error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip, @@ -623,7 +633,7 @@ again: return 0; out_error_or_again: - if (error == -EAGAIN) { + if (!(flags & XFS_IGET_INCORE) && error == -EAGAIN) { delay(1); goto again; } @@ -632,6 +642,44 @@ out_error_or_again: } /* + * "Is this a cached inode that's also allocated?" + * + * Look up an inode by number in the given file system. If the inode is + * in cache and isn't in purgatory, return 1 if the inode is allocated + * and 0 if it is not. For all other cases (not in cache, being torn + * down, etc.), return a negative error code. + * + * The caller has to prevent inode allocation and freeing activity, + * presumably by locking the AGI buffer. This is to ensure that an + * inode cannot transition from allocated to freed until the caller is + * ready to allow that. If the inode is in an intermediate state (new, + * reclaimable, or being reclaimed), -EAGAIN will be returned; if the + * inode is not in the cache, -ENOENT will be returned. The caller must + * deal with these scenarios appropriately. + * + * This is a specialized use case for the online scrubber; if you're + * reading this, you probably want xfs_iget. + */ +int +xfs_icache_inode_is_allocated( + struct xfs_mount *mp, + struct xfs_trans *tp, + xfs_ino_t ino, + bool *inuse) +{ + struct xfs_inode *ip; + int error; + + error = xfs_iget(mp, tp, ino, XFS_IGET_INCORE, 0, &ip); + if (error) + return error; + + *inuse = !!(VFS_I(ip)->i_mode); + IRELE(ip); + return 0; +} + +/* * The inode lookup is done in batches to keep the amount of lock traffic and * radix tree lookups to a minimum. The batch size is a trade off between * lookup reduction and stack usage. This is in the reclaim path, so we can't diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h index 9183f77958ef..bff4d85e5498 100644 --- a/fs/xfs/xfs_icache.h +++ b/fs/xfs/xfs_icache.h @@ -47,6 +47,7 @@ struct xfs_eofblocks { #define XFS_IGET_CREATE 0x1 #define XFS_IGET_UNTRUSTED 0x2 #define XFS_IGET_DONTCACHE 0x4 +#define XFS_IGET_INCORE 0x8 /* don't read from disk or reinit */ /* * flags for AG inode iterator @@ -126,4 +127,7 @@ xfs_fs_eofblocks_from_user( return 0; } +int xfs_icache_inode_is_allocated(struct xfs_mount *mp, struct xfs_trans *tp, + xfs_ino_t ino, bool *inuse); + #endif |