xfs: check if an inode is cached and allocated (378f681c) · Commits · 戴 / test

fs/xfs/xfs_icache.c

+50 −2

Original line number	Diff line number	Diff line
		@@ -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
		@@ -432,6 +437,7 @@ xfs_iget_cache_hit(
		if (lock_flags != 0)
		xfs_ilock(ip, lock_flags);

		if (!(flags & XFS_IGET_INCORE))
		xfs_iflags_clear(ip, XFS_ISTALE \| XFS_IDONTCACHE);
		XFS_STATS_INC(mp, xs_ig_found);

		@@ -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;
		}
		@@ -631,6 +641,44 @@ out_error_or_again:
		return error;
		}

		/*
		* "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

fs/xfs/xfs_icache.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -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

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