libxfs: make __cache_lookup return an error code

Convert __cache_lookup() to return numeric error codes like most
everywhere else in xfsprogs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c
index 7430ff099f3b692dc33cc22b67a65ed7d1870773..60fd042c6a6f67317341dc2181b6b94ea4ea2c3e 100644 (file)
--- a/libxfs/rdwr.c
+++ b/libxfs/rdwr.c
@@ -485,30 +485,40 @@ struct list_head  lock_buf_list = {&lock_buf_list, &lock_buf_list};
 int                    lock_buf_count = 0;
 #endif
 
-static struct xfs_buf *
-__cache_lookup(struct xfs_bufkey *key, unsigned int flags)
+static int
+__cache_lookup(
+       struct xfs_bufkey       *key,
+       unsigned int            flags,
+       struct xfs_buf          **bpp)
 {
-       struct xfs_buf  *bp;
+       struct cache_node       *cn = NULL;
+       struct xfs_buf          *bp;
 
-       cache_node_get(libxfs_bcache, key, (struct cache_node **)&bp);
-       if (!bp)
-               return NULL;
+       *bpp = NULL;
+
+       cache_node_get(libxfs_bcache, key, &cn);
+       if (!cn)
+               return -ENOMEM;
+       bp = container_of(cn, struct xfs_buf, b_node);
 
        if (use_xfs_buf_lock) {
-               int ret;
+               int             ret;
 
                ret = pthread_mutex_trylock(&bp->b_lock);
                if (ret) {
                        ASSERT(ret == EAGAIN);
-                       if (flags & LIBXFS_GETBUF_TRYLOCK)
-                               goto out_put;
+                       if (flags & LIBXFS_GETBUF_TRYLOCK) {
+                               cache_node_put(libxfs_bcache, cn);
+                               return -EAGAIN;
+                       }
 
                        if (pthread_equal(bp->b_holder, pthread_self())) {
                                fprintf(stderr,
        _("Warning: recursive buffer locking at block %" PRIu64 " detected\n"),
                                        key->blkno);
                                bp->b_recur++;
-                               return bp;
+                               *bpp = bp;
+                               return 0;
                        } else {
                                pthread_mutex_lock(&bp->b_lock);
                        }
@@ -517,9 +527,8 @@ __cache_lookup(struct xfs_bufkey *key, unsigned int flags)
                bp->b_holder = pthread_self();
        }
 
-       cache_node_set_priority(libxfs_bcache, &bp->b_node,
-                       cache_node_get_priority(&bp->b_node) -
-                                               CACHE_PREFETCH_PRIORITY);
+       cache_node_set_priority(libxfs_bcache, cn,
+                       cache_node_get_priority(cn) - CACHE_PREFETCH_PRIORITY);
 #ifdef XFS_BUF_TRACING
        pthread_mutex_lock(&libxfs_bcache->c_mutex);
        lock_buf_count++;
@@ -532,10 +541,8 @@ __cache_lookup(struct xfs_bufkey *key, unsigned int flags)
                bp, bp->b_bn, (long long)LIBXFS_BBTOOFF64(key->blkno));
 #endif
 
-       return bp;
-out_put:
-       cache_node_put(libxfs_bcache, &bp->b_node);
-       return NULL;
+       *bpp = bp;
+       return 0;
 }
 
 static struct xfs_buf *
@@ -545,13 +552,18 @@ libxfs_getbuf_flags(
        int                     len,
        unsigned int            flags)
 {
-       struct xfs_bufkey key = {NULL};
+       struct xfs_bufkey       key = {NULL};
+       struct xfs_buf          *bp;
+       int                     error;
 
        key.buftarg = btp;
        key.blkno = blkno;
        key.bblen = len;
 
-       return __cache_lookup(&key, flags);
+       error = __cache_lookup(&key, flags, &bp);
+       if (error)
+               return NULL;
+       return bp;
 }
 
 /*
@@ -575,11 +587,16 @@ reset_buf_state(
 }
 
 static struct xfs_buf *
-__libxfs_buf_get_map(struct xfs_buftarg *btp, struct xfs_buf_map *map,
-                   int nmaps, int flags)
+__libxfs_buf_get_map(
+       struct xfs_buftarg      *btp,
+       struct xfs_buf_map      *map,
+       int                     nmaps,
+       int                     flags)
 {
-       struct xfs_bufkey key = {NULL};
-       int i;
+       struct xfs_bufkey       key = {NULL};
+       struct xfs_buf          *bp;
+       int                     i;
+       int                     error;
 
        if (nmaps == 1)
                return libxfs_getbuf_flags(btp, map[0].bm_bn, map[0].bm_len,
@@ -593,7 +610,10 @@ __libxfs_buf_get_map(struct xfs_buftarg *btp, struct xfs_buf_map *map,
        key.map = map;
        key.nmaps = nmaps;
 
-       return __cache_lookup(&key, flags);
+       error = __cache_lookup(&key, flags, &bp);
+       if (error)
+               return NULL;
+       return bp;
 }
 
 struct xfs_buf *