[PATCH v3 3/6] xfs: move on-disk inode allocation out of xfs_ialloc()

Gao Xiang
2020-12-07T00:18:09Z

From: Dave Chinner <dchinner@redhat.com>

So xfs_ialloc() will only address in-core inode allocation then,
Also, rename xfs_ialloc() to xfs_dir_ialloc_init() in order to
keep everything in xfs_inode.c under the same namespace.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
---
fs/xfs/xfs_inode.c | 202 +++++++++++++++------------------------------
1 file changed, 66 insertions(+), 136 deletions(-)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 6672cdffcda5..22843e81bccf 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -761,68 +761,25 @@ xfs_inode_inherit_flags2(
}

/*
- * Allocate an inode on disk and return a copy of its in-core version.
- * The in-core inode is locked exclusively. Set mode, nlink, and rdev
- * appropriately within the inode. The uid and gid for the inode are
- * set according to the contents of the given cred structure.
- *
- * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
- * has a free inode available, call xfs_iget() to obtain the in-core
- * version of the allocated inode. Finally, fill in the inode and
- * log its initial contents. In this case, ialloc_context would be
- * set to NULL.
- *
- * If xfs_dialloc() does not have an available inode, it will replenish
- * its supply by doing an allocation. Since we can only do one
- * allocation within a transaction without deadlocks, we must commit
- * the current transaction before returning the inode itself.
- * In this case, therefore, we will set ialloc_context and return.
- * The caller should then commit the current transaction, start a new
- * transaction, and call xfs_ialloc() again to actually get the inode.
- *
- * To ensure that some other process does not grab the inode that
- * was allocated during the first call to xfs_ialloc(), this routine
- * also returns the [locked] bp pointing to the head of the freelist
- * as ialloc_context. The caller should hold this buffer across
- * the commit and pass it back into this routine on the second call.
- *
- * If we are allocating quota inodes, we do not have a parent inode
- * to attach to or associate with (i.e. pip == NULL) because they
- * are not linked into the directory structure - they are attached
- * directly to the superblock - and so have no parent.
+ * Initialise a newly allocated inode and return the in-core inode to the
+ * caller locked exclusively.
*/
-static int
-xfs_ialloc(
- xfs_trans_t *tp,
- xfs_inode_t *pip,
- umode_t mode,
- xfs_nlink_t nlink,
- dev_t rdev,
- prid_t prid,
- xfs_buf_t **ialloc_context,
- xfs_inode_t **ipp)
+static struct xfs_inode *
+xfs_dir_ialloc_init(
+ struct xfs_trans *tp,
+ struct xfs_inode *pip,
+ xfs_ino_t ino,
+ umode_t mode,
+ xfs_nlink_t nlink,
+ dev_t rdev,
+ prid_t prid)
{
- struct xfs_mount *mp = tp->t_mountp;
- xfs_ino_t ino;
- xfs_inode_t *ip;
- uint flags;
- int error;
- struct timespec64 tv;
- struct inode *inode;
-
- /*
- * Call the space management code to pick
- * the on-disk inode to be allocated.
- */
- error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode,
- ialloc_context, &ino);
- if (error)
- return error;
- if (*ialloc_context || ino == NULLFSINO) {
- *ipp = NULL;
- return 0;
- }
- ASSERT(*ialloc_context == NULL);
+ struct xfs_mount *mp = tp->t_mountp;
+ struct xfs_inode *ip;
+ unsigned int flags;
+ int error;
+ struct timespec64 tv;
+ struct inode *inode;

/*
* Protect against obviously corrupt allocation btree records. Later
@@ -833,18 +790,16 @@ xfs_ialloc(
*/
if ((pip && ino == pip->i_ino) || !xfs_verify_dir_ino(mp, ino)) {
xfs_alert(mp, "Allocated a known in-use inode 0x%llx!", ino);
- return -EFSCORRUPTED;
+ return ERR_PTR(-EFSCORRUPTED);
}

/*
- * Get the in-core inode with the lock held exclusively.
- * This is because we're setting fields here we need
- * to prevent others from looking at until we're done.
+ * Get the in-core inode with the lock held exclusively to prevent
+ * others from looking at until we're done.
*/
- error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE,
- XFS_ILOCK_EXCL, &ip);
+ error = xfs_iget(mp, tp, ino, XFS_IGET_CREATE, XFS_ILOCK_EXCL, &ip);
if (error)
- return error;
+ return ERR_PTR(error);
ASSERT(ip != NULL);
inode = VFS_I(ip);
inode->i_mode = mode;
@@ -926,20 +881,19 @@ xfs_ialloc(

/* now that we have an i_mode we can setup the inode structure */
xfs_setup_inode(ip);
-
- *ipp = ip;
- return 0;
+ return ip;
}

/*
- * Allocates a new inode from disk and return a pointer to the
- * incore copy. This routine will internally commit the current
- * transaction and allocate a new one if the Space Manager needed
- * to do an allocation to replenish the inode free-list.
- *
- * This routine is designed to be called from xfs_create and
- * xfs_create_dir.
+ * Allocates a new inode from disk and return a pointer to the incore copy. This
+ * routine will internally commit the current transaction and allocate a new one
+ * if we needed to allocate more on-disk free inodes to perform the requested
+ * operation.
*
+ * If we are allocating quota inodes, we do not have a parent inode to attach to
+ * or associate with (i.e. dp == NULL) because they are not linked into the
+ * directory structure - they are attached directly to the superblock - and so
+ * have no parent.
*/
int
xfs_dir_ialloc(
@@ -954,83 +908,59 @@ xfs_dir_ialloc(
xfs_inode_t **ipp) /* pointer to inode; it will be
locked. */
{
- xfs_trans_t *tp;
xfs_inode_t *ip;
xfs_buf_t *ialloc_context = NULL;
- int code;
-
- tp = *tpp;
- ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
+ xfs_ino_t pino = dp ? dp->i_ino : 0;
+ xfs_ino_t ino;
+ int error;

- /*
- * xfs_ialloc will return a pointer to an incore inode if
- * the Space Manager has an available inode on the free
- * list. Otherwise, it will do an allocation and replenish
- * the freelist. Since we can only do one allocation per
- * transaction without deadlocks, we will need to commit the
- * current transaction and start a new one. We will then
- * need to call xfs_ialloc again to get the inode.
- *
- * If xfs_ialloc did an allocation to replenish the freelist,
- * it returns the bp containing the head of the freelist as
- * ialloc_context. We will hold a lock on it across the
- * transaction commit so that no other process can steal
- * the inode(s) that we've just allocated.
- */
- code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, &ialloc_context,
- &ip);
+ ASSERT((*tpp)->t_flags & XFS_TRANS_PERM_LOG_RES);
+ *ipp = NULL;

/*
- * Return an error if we were unable to allocate a new inode.
- * This should only happen if we run out of space on disk or
- * encounter a disk error.
+ * Call the space management code to pick the on-disk inode to be
+ * allocated and replenish the freelist. Since we can only do one
+ * allocation per transaction without deadlocks, we will need to
+ * commit the current transaction and start a new one.
+ * If xfs_dialloc did an allocation to replenish the freelist, it
+ * returns the bp containing the head of the freelist as
+ * ialloc_context. We will hold a lock on it across the transaction
+ * commit so that no other process can steal the inode(s) that we've
+ * just allocated.
*/
- if (code) {
- *ipp = NULL;
- return code;
- }
- if (!ialloc_context && !ip) {
- *ipp = NULL;
- return -ENOSPC;
- }
+ error = xfs_dialloc(*tpp, pino, mode, &ialloc_context, &ino);
+ if (error)
+ return error;

/*
* If the AGI buffer is non-NULL, then we were unable to get an
* inode in one operation. We need to commit the current
- * transaction and call xfs_ialloc() again. It is guaranteed
+ * transaction and call xfs_dialloc() again. It is guaranteed
* to succeed the second time.
*/
if (ialloc_context) {
- code = xfs_dialloc_roll(&tp, ialloc_context);
- if (code) {
- *tpp = tp;
- *ipp = NULL;
- return code;
- }
-
- /*
- * Call ialloc again. Since we've locked out all
- * other allocations in this allocation group,
- * this call should always succeed.
- */
- code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
- &ialloc_context, &ip);
-
+ error = xfs_dialloc_roll(tpp, ialloc_context);
+ if (error)
+ return error;
/*
- * If we get an error at this point, return to the caller
- * so that the current transaction can be aborted.
+ * Call dialloc again. Since we've locked out all other
+ * allocations in this allocation group, this call should
+ * always succeed.
*/
- if (code) {
- *tpp = tp;
- *ipp = NULL;
- return code;
- }
- ASSERT(!ialloc_context && ip);
+ error = xfs_dialloc(*tpp, pino, mode, &ialloc_context, &ino);
+ if (error)
+ return error;
+ ASSERT(!ialloc_context);
}

- *ipp = ip;
- *tpp = tp;
+ if (ino == NULLFSINO)
+ return -ENOSPC;

+ /* Initialise the newly allocated inode. */
+ ip = xfs_dir_ialloc_init(*tpp, dp, ino, mode, nlink, rdev, prid);
+ if (IS_ERR(ip))
+ return PTR_ERR(ip);
+ *ipp = ip;
return 0;
}

--
2.18.4