#include "xfs_utils.h"
/*
- * Look up an inode by number in the given file system.
- * The inode is looked up in the cache held in each AG.
- * If the inode is found in the cache, attach it to the provided
- * vnode.
- *
- * If it is not in core, read it in from the file system's device,
- * add it to the cache and attach the provided vnode.
- *
- * The inode is locked according to the value of the lock_flags parameter.
- * This flag parameter indicates how and if the inode's IO lock and inode lock
- * should be taken.
- *
- * mp -- the mount point structure for the current file system. It points
- * to the inode hash table.
- * tp -- a pointer to the current transaction if there is one. This is
- * simply passed through to the xfs_iread() call.
- * ino -- the number of the inode desired. This is the unique identifier
- * within the file system for the inode being requested.
- * lock_flags -- flags indicating how to lock the inode. See the comment
- * for xfs_ilock() for a list of valid values.
- * bno -- the block number starting the buffer containing the inode,
- * if known (as by bulkstat), else 0.
+ * Check the validity of the inode we just found it the cache
*/
-STATIC int
-xfs_iget_core(
- struct inode *inode,
- xfs_mount_t *mp,
- xfs_trans_t *tp,
- xfs_ino_t ino,
- uint flags,
- uint lock_flags,
- xfs_inode_t **ipp,
- xfs_daddr_t bno)
+static int
+xfs_iget_cache_hit(
+ struct inode *inode,
+ struct xfs_perag *pag,
+ struct xfs_inode *ip,
+ int flags,
+ int lock_flags) __releases(pag->pag_ici_lock)
{
- struct inode *old_inode;
- xfs_inode_t *ip;
- int error;
- unsigned long first_index, mask;
- xfs_perag_t *pag;
- xfs_agino_t agino;
+ struct xfs_mount *mp = ip->i_mount;
+ struct inode *old_inode;
+ int error = 0;
- /* the radix tree exists only in inode capable AGs */
- if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi)
- return EINVAL;
-
- /* get the perag structure and ensure that it's inode capable */
- pag = xfs_get_perag(mp, ino);
- if (!pag->pagi_inodeok)
- return EINVAL;
- ASSERT(pag->pag_ici_init);
- agino = XFS_INO_TO_AGINO(mp, ino);
-
-again:
- read_lock(&pag->pag_ici_lock);
- ip = radix_tree_lookup(&pag->pag_ici_root, agino);
+ /*
+ * If INEW is set this inode is being set up
+ * Pause and try again.
+ */
+ if (xfs_iflags_test(ip, XFS_INEW)) {
+ error = EAGAIN;
+ XFS_STATS_INC(xs_ig_frecycle);
+ goto out_error;
+ }
- if (ip != NULL) {
+ old_inode = ip->i_vnode;
+ if (old_inode == NULL) {
/*
- * If INEW is set this inode is being set up
+ * If IRECLAIM is set this inode is
+ * on its way out of the system,
* we need to pause and try again.
*/
- if (xfs_iflags_test(ip, XFS_INEW)) {
- read_unlock(&pag->pag_ici_lock);
- delay(1);
+ if (xfs_iflags_test(ip, XFS_IRECLAIM)) {
+ error = EAGAIN;
XFS_STATS_INC(xs_ig_frecycle);
+ goto out_error;
+ }
+ ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE));
- goto again;
+ /*
+ * If lookup is racing with unlink, then we
+ * should return an error immediately so we
+ * don't remove it from the reclaim list and
+ * potentially leak the inode.
+ */
+ if ((ip->i_d.di_mode == 0) &&
+ !(flags & XFS_IGET_CREATE)) {
+ error = ENOENT;
+ goto out_error;
}
+ xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
- old_inode = ip->i_vnode;
- if (old_inode == NULL) {
- /*
- * If IRECLAIM is set this inode is
- * on its way out of the system,
- * we need to pause and try again.
- */
- if (xfs_iflags_test(ip, XFS_IRECLAIM)) {
- read_unlock(&pag->pag_ici_lock);
- delay(1);
- XFS_STATS_INC(xs_ig_frecycle);
-
- goto again;
- }
- ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE));
-
- /*
- * If lookup is racing with unlink, then we
- * should return an error immediately so we
- * don't remove it from the reclaim list and
- * potentially leak the inode.
- */
- if ((ip->i_d.di_mode == 0) &&
- !(flags & XFS_IGET_CREATE)) {
- read_unlock(&pag->pag_ici_lock);
- xfs_put_perag(mp, pag);
- return ENOENT;
- }
-
- xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
-
- XFS_STATS_INC(xs_ig_found);
- xfs_iflags_clear(ip, XFS_IRECLAIMABLE);
- read_unlock(&pag->pag_ici_lock);
-
- XFS_MOUNT_ILOCK(mp);
- list_del_init(&ip->i_reclaim);
- XFS_MOUNT_IUNLOCK(mp);
-
- goto finish_inode;
-
- } else if (inode != old_inode) {
- /* The inode is being torn down, pause and
- * try again.
- */
- if (old_inode->i_state & (I_FREEING | I_CLEAR)) {
- read_unlock(&pag->pag_ici_lock);
- delay(1);
- XFS_STATS_INC(xs_ig_frecycle);
-
- goto again;
- }
+ xfs_iflags_clear(ip, XFS_IRECLAIMABLE);
+ read_unlock(&pag->pag_ici_lock);
+
+ XFS_MOUNT_ILOCK(mp);
+ list_del_init(&ip->i_reclaim);
+ XFS_MOUNT_IUNLOCK(mp);
+
+ } else if (inode != old_inode) {
+ /* The inode is being torn down, pause and
+ * try again.
+ */
+ if (old_inode->i_state & (I_FREEING | I_CLEAR)) {
+ error = EAGAIN;
+ XFS_STATS_INC(xs_ig_frecycle);
+ goto out_error;
+ }
/* Chances are the other vnode (the one in the inode) is being torn
* down right now, and we landed on top of it. Question is, what do
* we do? Unhook the old inode and hook up the new one?
*/
- cmn_err(CE_PANIC,
- "xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p",
- old_inode, inode);
- }
-
- /*
- * Inode cache hit
- */
+ cmn_err(CE_PANIC,
+ "xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p",
+ old_inode, inode);
+ } else {
read_unlock(&pag->pag_ici_lock);
- XFS_STATS_INC(xs_ig_found);
+ }
-finish_inode:
- if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
- xfs_put_perag(mp, pag);
- return ENOENT;
- }
+ if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
+ error = ENOENT;
+ goto out;
+ }
- if (lock_flags != 0)
- xfs_ilock(ip, lock_flags);
+ if (lock_flags != 0)
+ xfs_ilock(ip, lock_flags);
- xfs_iflags_clear(ip, XFS_ISTALE);
- xfs_itrace_exit_tag(ip, "xfs_iget.found");
- goto return_ip;
- }
+ xfs_iflags_clear(ip, XFS_ISTALE);
+ xfs_itrace_exit_tag(ip, "xfs_iget.found");
+ XFS_STATS_INC(xs_ig_found);
+ return 0;
- /*
- * Inode cache miss
- */
+out_error:
read_unlock(&pag->pag_ici_lock);
- XFS_STATS_INC(xs_ig_missed);
+out:
+ return error;
+}
+
+
+static int
+xfs_iget_cache_miss(
+ struct xfs_mount *mp,
+ struct xfs_perag *pag,
+ xfs_trans_t *tp,
+ xfs_ino_t ino,
+ struct xfs_inode **ipp,
+ xfs_daddr_t bno,
+ int flags,
+ int lock_flags) __releases(pag->pag_ici_lock)
+{
+ struct xfs_inode *ip;
+ int error;
+ unsigned long first_index, mask;
+ xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
/*
* Read the disk inode attributes into a new inode structure and get
*/
error = xfs_iread(mp, tp, ino, &ip, bno,
(flags & XFS_IGET_BULKSTAT) ? XFS_IMAP_BULKSTAT : 0);
- if (error) {
- xfs_put_perag(mp, pag);
+ if (error)
return error;
- }
xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
- xfs_idestroy(ip);
- xfs_put_perag(mp, pag);
- return ENOENT;
+ error = ENOENT;
+ goto out_destroy;
}
/*
* write spinlock.
*/
if (radix_tree_preload(GFP_KERNEL)) {
- xfs_idestroy(ip);
- delay(1);
- goto again;
+ error = EAGAIN;
+ goto out_destroy;
}
if (lock_flags)
mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1);
first_index = agino & mask;
write_lock(&pag->pag_ici_lock);
- /*
- * insert the new inode
- */
+
+ /* insert the new inode */
error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
if (unlikely(error)) {
- BUG_ON(error != -EEXIST);
- write_unlock(&pag->pag_ici_lock);
- radix_tree_preload_end();
- if (lock_flags)
- xfs_iunlock(ip, lock_flags);
- xfs_idestroy(ip);
+ WARN_ON(error != -EEXIST);
XFS_STATS_INC(xs_ig_dup);
- goto again;
+ error = EAGAIN;
+ goto out_unlock;
}
- /*
- * These values _must_ be set before releasing the radix tree lock!
- */
+ /* These values _must_ be set before releasing the radix tree lock! */
ip->i_udquot = ip->i_gdquot = NULL;
xfs_iflags_set(ip, XFS_INEW);
write_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
+ *ipp = ip;
+ return 0;
+
+out_unlock:
+ write_unlock(&pag->pag_ici_lock);
+ radix_tree_preload_end();
+out_destroy:
+ xfs_idestroy(ip);
+ return error;
+}
+
+/*
+ * Look up an inode by number in the given file system.
+ * The inode is looked up in the cache held in each AG.
+ * If the inode is found in the cache, attach it to the provided
+ * vnode.
+ *
+ * If it is not in core, read it in from the file system's device,
+ * add it to the cache and attach the provided vnode.
+ *
+ * The inode is locked according to the value of the lock_flags parameter.
+ * This flag parameter indicates how and if the inode's IO lock and inode lock
+ * should be taken.
+ *
+ * mp -- the mount point structure for the current file system. It points
+ * to the inode hash table.
+ * tp -- a pointer to the current transaction if there is one. This is
+ * simply passed through to the xfs_iread() call.
+ * ino -- the number of the inode desired. This is the unique identifier
+ * within the file system for the inode being requested.
+ * lock_flags -- flags indicating how to lock the inode. See the comment
+ * for xfs_ilock() for a list of valid values.
+ * bno -- the block number starting the buffer containing the inode,
+ * if known (as by bulkstat), else 0.
+ */
+STATIC int
+xfs_iget_core(
+ struct inode *inode,
+ xfs_mount_t *mp,
+ xfs_trans_t *tp,
+ xfs_ino_t ino,
+ uint flags,
+ uint lock_flags,
+ xfs_inode_t **ipp,
+ xfs_daddr_t bno)
+{
+ xfs_inode_t *ip;
+ int error;
+ xfs_perag_t *pag;
+ xfs_agino_t agino;
+
+ /* the radix tree exists only in inode capable AGs */
+ if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi)
+ return EINVAL;
+
+ /* get the perag structure and ensure that it's inode capable */
+ pag = xfs_get_perag(mp, ino);
+ if (!pag->pagi_inodeok)
+ return EINVAL;
+ ASSERT(pag->pag_ici_init);
+ agino = XFS_INO_TO_AGINO(mp, ino);
+
+again:
+ error = 0;
+ read_lock(&pag->pag_ici_lock);
+ ip = radix_tree_lookup(&pag->pag_ici_root, agino);
+
+ if (ip) {
+ error = xfs_iget_cache_hit(inode, pag, ip, flags, lock_flags);
+ if (error)
+ goto out_error_or_again;
+ } else {
+ read_unlock(&pag->pag_ici_lock);
+ XFS_STATS_INC(xs_ig_missed);
+
+ error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip, bno,
+ flags, lock_flags);
+ if (error)
+ goto out_error_or_again;
+ }
xfs_put_perag(mp, pag);
- return_ip:
ASSERT(ip->i_df.if_ext_max ==
XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t));
if (ip->i_d.di_mode != 0)
xfs_setup_inode(ip);
return 0;
+
+out_error_or_again:
+ if (error == EAGAIN) {
+ delay(1);
+ goto again;
+ }
+ xfs_put_perag(mp, pag);
+ return error;
}
projects / ~andy / linux / blobdiff