[PATCH v11 03/25] xfs: Factor out new helper functions xfs_attr_rmtval_set

Allison Collins
2020-07-21T00:16:19Z

Break xfs_attr_rmtval_set into two helper functions
xfs_attr_rmt_find_hole and xfs_attr_rmtval_set_value.
xfs_attr_rmtval_set rolls the transaction between the helpers, but
delayed operations cannot. We will use the helpers later when
constructing new delayed attribute routines.

Signed-off-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
---
fs/xfs/libxfs/xfs_attr_remote.c | 149 +++++++++++++++++++++++++---------------
1 file changed, 92 insertions(+), 57 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
index 01ad7f3..f825eed 100644
--- a/fs/xfs/libxfs/xfs_attr_remote.c
+++ b/fs/xfs/libxfs/xfs_attr_remote.c
@@ -440,32 +440,23 @@ xfs_attr_rmtval_get(
}

/*
- * Write the value associated with an attribute into the out-of-line buffer
- * that we have defined for it.
+ * Find a "hole" in the attribute address space large enough for us to drop the
+ * new attribute's value into
*/
-int
-xfs_attr_rmtval_set(
+STATIC int
+xfs_attr_rmt_find_hole(
struct xfs_da_args *args)
{
struct xfs_inode *dp = args->dp;
struct xfs_mount *mp = dp->i_mount;
- struct xfs_bmbt_irec map;
- xfs_dablk_t lblkno;
- xfs_fileoff_t lfileoff = 0;
- uint8_t *src = args->value;
- int blkcnt;
- int valuelen;
- int nmap;
int error;
- int offset = 0;
-
- trace_xfs_attr_rmtval_set(args);
+ int blkcnt;
+ xfs_fileoff_t lfileoff = 0;

/*
- * Find a "hole" in the attribute address space large enough for
- * us to drop the new attribute's value into. Because CRC enable
- * attributes have headers, we can't just do a straight byte to FSB
- * conversion and have to take the header space into account.
+ * Because CRC enable attributes have headers, we can't just do a
+ * straight byte to FSB conversion and have to take the header space
+ * into account.
*/
blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
@@ -473,48 +464,26 @@ xfs_attr_rmtval_set(
if (error)
return error;

- args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
+ args->rmtblkno = (xfs_dablk_t)lfileoff;
args->rmtblkcnt = blkcnt;

- /*
- * Roll through the "value", allocating blocks on disk as required.
- */
- while (blkcnt > 0) {
- /*
- * Allocate a single extent, up to the size of the value.
- *
- * Note that we have to consider this a data allocation as we
- * write the remote attribute without logging the contents.
- * Hence we must ensure that we aren't using blocks that are on
- * the busy list so that we don't overwrite blocks which have
- * recently been freed but their transactions are not yet
- * committed to disk. If we overwrite the contents of a busy
- * extent and then crash then the block may not contain the
- * correct metadata after log recovery occurs.
- */
- nmap = 1;
- error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
- blkcnt, XFS_BMAPI_ATTRFORK, args->total, &map,
- &nmap);
- if (error)
- return error;
- error = xfs_defer_finish(&args->trans);
- if (error)
- return error;
-
- ASSERT(nmap == 1);
- ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
- (map.br_startblock != HOLESTARTBLOCK));
- lblkno += map.br_blockcount;
- blkcnt -= map.br_blockcount;
+ return 0;
+}

- /*
- * Start the next trans in the chain.
- */
- error = xfs_trans_roll_inode(&args->trans, dp);
- if (error)
- return error;
- }
+STATIC int
+xfs_attr_rmtval_set_value(
+ struct xfs_da_args *args)
+{
+ struct xfs_inode *dp = args->dp;
+ struct xfs_mount *mp = dp->i_mount;
+ struct xfs_bmbt_irec map;
+ xfs_dablk_t lblkno;
+ uint8_t *src = args->value;
+ int blkcnt;
+ int valuelen;
+ int nmap;
+ int error;
+ int offset = 0;

/*
* Roll through the "value", copying the attribute value to the
@@ -595,6 +564,72 @@ xfs_attr_rmtval_stale(
}

/*
+ * Write the value associated with an attribute into the out-of-line buffer
+ * that we have defined for it.
+ */
+int
+xfs_attr_rmtval_set(
+ struct xfs_da_args *args)
+{
+ struct xfs_inode *dp = args->dp;
+ struct xfs_bmbt_irec map;
+ xfs_dablk_t lblkno;
+ int blkcnt;
+ int nmap;
+ int error;
+
+ trace_xfs_attr_rmtval_set(args);
+
+ error = xfs_attr_rmt_find_hole(args);
+ if (error)
+ return error;
+
+ blkcnt = args->rmtblkcnt;
+ lblkno = (xfs_dablk_t)args->rmtblkno;
+ /*
+ * Roll through the "value", allocating blocks on disk as required.
+ */
+ while (blkcnt > 0) {
+ /*
+ * Allocate a single extent, up to the size of the value.
+ *
+ * Note that we have to consider this a data allocation as we
+ * write the remote attribute without logging the contents.
+ * Hence we must ensure that we aren't using blocks that are on
+ * the busy list so that we don't overwrite blocks which have
+ * recently been freed but their transactions are not yet
+ * committed to disk. If we overwrite the contents of a busy
+ * extent and then crash then the block may not contain the
+ * correct metadata after log recovery occurs.
+ */
+ nmap = 1;
+ error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
+ blkcnt, XFS_BMAPI_ATTRFORK, args->total, &map,
+ &nmap);
+ if (error)
+ return error;
+ error = xfs_defer_finish(&args->trans);
+ if (error)
+ return error;
+
+ ASSERT(nmap == 1);
+ ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
+ (map.br_startblock != HOLESTARTBLOCK));
+ lblkno += map.br_blockcount;
+ blkcnt -= map.br_blockcount;
+
+ /*
+ * Start the next trans in the chain.
+ */
+ error = xfs_trans_roll_inode(&args->trans, dp);
+ if (error)
+ return error;
+ }
+
+ return xfs_attr_rmtval_set_value(args);
+}
+
+/*
* Remove the value associated with an attribute by deleting the
* out-of-line buffer that it is stored on.
*/
--
2.7.4