xfs: introduce xlog_copy_iovec

Add a helper to abstract out filling the log iovecs in the log item
format handlers.  This will allow us to change the way we do the log
item formatting more easily.

The copy in the name is a bit confusing for now as it just assigns a
pointer and lets the CIL code perform the copy, but that will change
soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

6 files changed, 103 insertions, 108 deletions

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index a30c1fb1bec6..d49419d4bb46 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -182,20 +182,18 @@ xfs_buf_item_size(
         trace_xfs_buf_item_size(bip);
 }
 
-static inline struct xfs_log_iovec *
+static inline void
 xfs_buf_item_copy_iovec(
-        struct xfs_log_iovec    *vecp,
+        struct xfs_log_iovec    **vecp,
         struct xfs_buf          *bp,
         uint                    offset,
         int                     first_bit,
         uint                    nbits)
 {
         offset += first_bit * XFS_BLF_CHUNK;
-
-        vecp->i_type = XLOG_REG_TYPE_BCHUNK;
-        vecp->i_addr = xfs_buf_offset(bp, offset);
-        vecp->i_len = nbits * XFS_BLF_CHUNK;
-        return vecp + 1;
+        xlog_copy_iovec(vecp, XLOG_REG_TYPE_BCHUNK,
+                        xfs_buf_offset(bp, offset),
+                        nbits * XFS_BLF_CHUNK);
 }
 
 static inline bool
@@ -210,10 +208,10 @@ xfs_buf_item_straddle(
                  XFS_BLF_CHUNK);
 }
 
-static struct xfs_log_iovec *
+static void
 xfs_buf_item_format_segment(
         struct xfs_buf_log_item *bip,
-        struct xfs_log_iovec    *vecp,
+        struct xfs_log_iovec    **vecp,
         uint                    offset,
         struct xfs_buf_log_format *blfp)
 {
@@ -245,10 +243,7 @@ xfs_buf_item_format_segment(
                 goto out;
         }
 
-        vecp->i_addr = blfp;
-        vecp->i_len = base_size;
-        vecp->i_type = XLOG_REG_TYPE_BFORMAT;
-        vecp++;
+        xlog_copy_iovec(vecp, XLOG_REG_TYPE_BFORMAT, blfp, base_size);
         nvecs = 1;
 
         if (bip->bli_flags & XFS_BLI_STALE) {
@@ -291,8 +286,8 @@ xfs_buf_item_format_segment(
                         break;
                 } else if (next_bit != last_bit + 1 ||
                            xfs_buf_item_straddle(bp, offset, next_bit, last_bit)) {
-                        vecp = xfs_buf_item_copy_iovec(vecp, bp, offset,
-                                                       first_bit, nbits);
+                        xfs_buf_item_copy_iovec(vecp, bp, offset,
+                                                first_bit, nbits);
                         nvecs++;
                         first_bit = next_bit;
                         last_bit = next_bit;
@@ -304,7 +299,6 @@ xfs_buf_item_format_segment(
         }
 out:
         blfp->blf_size = nvecs;
-        return vecp;
 }
 
 /*
@@ -360,8 +354,8 @@ xfs_buf_item_format(
         }
 
         for (i = 0; i < bip->bli_format_count; i++) {
-                vecp = xfs_buf_item_format_segment(bip, vecp, offset,
-                                                &bip->bli_formats[i]);
+                xfs_buf_item_format_segment(bip, &vecp, offset,
+                                            &bip->bli_formats[i]);
                 offset += bp->b_maps[i].bm_len;
         }
 
diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c
index 92e5f62eefc6..ca354a821838 100644
--- a/fs/xfs/xfs_dquot_item.c
+++ b/fs/xfs/xfs_dquot_item.c
@@ -57,20 +57,18 @@ xfs_qm_dquot_logitem_size(
 STATIC void
 xfs_qm_dquot_logitem_format(
         struct xfs_log_item     *lip,
-        struct xfs_log_iovec    *logvec)
+        struct xfs_log_iovec    *vecp)
 {
         struct xfs_dq_logitem   *qlip = DQUOT_ITEM(lip);
 
-        logvec->i_addr = &qlip->qli_format;
-        logvec->i_len  = sizeof(xfs_dq_logformat_t);
-        logvec->i_type = XLOG_REG_TYPE_QFORMAT;
-        logvec++;
-        logvec->i_addr = &qlip->qli_dquot->q_core;
-        logvec->i_len  = sizeof(xfs_disk_dquot_t);
-        logvec->i_type = XLOG_REG_TYPE_DQUOT;
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_QFORMAT,
+                        &qlip->qli_format,
+                        sizeof(struct xfs_dq_logformat));
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_DQUOT,
+                        &qlip->qli_dquot->q_core,
+                        sizeof(struct xfs_disk_dquot));
 
         qlip->qli_format.qlf_size = 2;
-
 }
 
 /*
@@ -304,15 +302,16 @@ xfs_qm_qoff_logitem_size(
 STATIC void
 xfs_qm_qoff_logitem_format(
         struct xfs_log_item     *lip,
-        struct xfs_log_iovec    *log_vector)
+        struct xfs_log_iovec    *vecp)
 {
         struct xfs_qoff_logitem *qflip = QOFF_ITEM(lip);
 
         ASSERT(qflip->qql_format.qf_type == XFS_LI_QUOTAOFF);
 
-        log_vector->i_addr = &qflip->qql_format;
-        log_vector->i_len = sizeof(xfs_qoff_logitem_t);
-        log_vector->i_type = XLOG_REG_TYPE_QUOTAOFF;
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_QUOTAOFF,
+                        &qflip->qql_format,
+                        sizeof(struct xfs_qoff_logitem));
+
         qflip->qql_format.qf_size = 1;
 }
 
diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
index 3680d04f973f..08823ecbcd82 100644
--- a/fs/xfs/xfs_extfree_item.c
+++ b/fs/xfs/xfs_extfree_item.c
@@ -26,6 +26,7 @@
 #include "xfs_trans_priv.h"
 #include "xfs_buf_item.h"
 #include "xfs_extfree_item.h"
+#include "xfs_log.h"
 
 
 kmem_zone_t     *xfs_efi_zone;
@@ -101,7 +102,7 @@ xfs_efi_item_size(
 STATIC void
 xfs_efi_item_format(
         struct xfs_log_item     *lip,
-        struct xfs_log_iovec    *log_vector)
+        struct xfs_log_iovec    *vecp)
 {
         struct xfs_efi_log_item *efip = EFI_ITEM(lip);
 
@@ -111,10 +112,9 @@ xfs_efi_item_format(
         efip->efi_format.efi_type = XFS_LI_EFI;
         efip->efi_format.efi_size = 1;
 
-        log_vector->i_addr = &efip->efi_format;
-        log_vector->i_len = xfs_efi_item_sizeof(efip);
-        log_vector->i_type = XLOG_REG_TYPE_EFI_FORMAT;
-        ASSERT(log_vector->i_len >= sizeof(xfs_efi_log_format_t));
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_EFI_FORMAT,
+                        &efip->efi_format,
+                        xfs_efi_item_sizeof(efip));
 }
 
 
@@ -368,7 +368,7 @@ xfs_efd_item_size(
 STATIC void
 xfs_efd_item_format(
         struct xfs_log_item     *lip,
-        struct xfs_log_iovec    *log_vector)
+        struct xfs_log_iovec    *vecp)
 {
         struct xfs_efd_log_item *efdp = EFD_ITEM(lip);
 
@@ -377,10 +377,9 @@ xfs_efd_item_format(
         efdp->efd_format.efd_type = XFS_LI_EFD;
         efdp->efd_format.efd_size = 1;
 
-        log_vector->i_addr = &efdp->efd_format;
-        log_vector->i_len = xfs_efd_item_sizeof(efdp);
-        log_vector->i_type = XLOG_REG_TYPE_EFD_FORMAT;
-        ASSERT(log_vector->i_len >= sizeof(xfs_efd_log_format_t));
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_EFD_FORMAT,
+                        &efdp->efd_format,
+                        xfs_efd_item_sizeof(efdp));
 }
 
 /*
diff --git a/fs/xfs/xfs_icreate_item.c b/fs/xfs/xfs_icreate_item.c
index d2eaccfa73f4..5751fa8580ee 100644
--- a/fs/xfs/xfs_icreate_item.c
+++ b/fs/xfs/xfs_icreate_item.c
@@ -28,6 +28,7 @@
 #include "xfs_trans_priv.h"
 #include "xfs_error.h"
 #include "xfs_icreate_item.h"
+#include "xfs_log.h"
 
 kmem_zone_t     *xfs_icreate_zone;              /* inode create item zone */
 
@@ -58,13 +59,13 @@ xfs_icreate_item_size(
 STATIC void
 xfs_icreate_item_format(
         struct xfs_log_item     *lip,
-        struct xfs_log_iovec    *log_vector)
+        struct xfs_log_iovec    *vecp)
 {
         struct xfs_icreate_item *icp = ICR_ITEM(lip);
 
-        log_vector->i_addr = (xfs_caddr_t)&icp->ic_format;
-        log_vector->i_len  = sizeof(struct xfs_icreate_log);
-        log_vector->i_type = XLOG_REG_TYPE_ICREATE;
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_ICREATE,
+                        &icp->ic_format,
+                        sizeof(struct xfs_icreate_log));
 }
 
 
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 2ad12dcf8311..c75e14beff06 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -30,6 +30,7 @@
 #include "xfs_trace.h"
 #include "xfs_trans_priv.h"
 #include "xfs_dinode.h"
+#include "xfs_log.h"
 
 
 kmem_zone_t     *xfs_ili_zone;          /* inode log item zone */
@@ -159,14 +160,15 @@ xfs_inode_item_size(
  * here, so always use the physical fork size to determine the size of the
  * buffer we need to allocate.
  */
-STATIC void
+STATIC int
 xfs_inode_item_format_extents(
         struct xfs_inode        *ip,
-        struct xfs_log_iovec    *vecp,
+        struct xfs_log_iovec    **vecp,
         int                     whichfork,
         int                     type)
 {
         xfs_bmbt_rec_t          *ext_buffer;
+        int                     len;
 
         ext_buffer = kmem_alloc(XFS_IFORK_SIZE(ip, whichfork), KM_SLEEP);
         if (whichfork == XFS_DATA_FORK)
@@ -174,9 +176,9 @@ xfs_inode_item_format_extents(
         else
                 ip->i_itemp->ili_aextents_buf = ext_buffer;
 
-        vecp->i_addr = ext_buffer;
-        vecp->i_len = xfs_iextents_copy(ip, ext_buffer, whichfork);
-        vecp->i_type = type;
+        len = xfs_iextents_copy(ip, ext_buffer, whichfork);
+        xlog_copy_iovec(vecp, type, ext_buffer, len);
+        return len;
 }
 
 /*
@@ -207,10 +209,10 @@ xfs_inode_item_format_v1_inode(
         }
 }
 
-STATIC struct xfs_log_iovec *
+STATIC void
 xfs_inode_item_format_data_fork(
         struct xfs_inode_log_item *iip,
-        struct xfs_log_iovec    *vecp,
+        struct xfs_log_iovec    **vecp,
         int                     *nvecs)
 {
         struct xfs_inode        *ip = iip->ili_inode;
@@ -237,18 +239,18 @@ xfs_inode_item_format_data_fork(
                                  * extents, so just point to the
                                  * real extents array.
                                  */
-                                vecp->i_addr = ip->i_df.if_u1.if_extents;
-                                vecp->i_len = ip->i_df.if_bytes;
-                                vecp->i_type = XLOG_REG_TYPE_IEXT;
+                                xlog_copy_iovec(vecp, XLOG_REG_TYPE_IEXT,
+                                                ip->i_df.if_u1.if_extents,
+                                                ip->i_df.if_bytes);
+                                iip->ili_format.ilf_dsize = ip->i_df.if_bytes;
                         } else
 #endif
                         {
-                                xfs_inode_item_format_extents(ip, vecp,
-                                        XFS_DATA_FORK, XLOG_REG_TYPE_IEXT);
+                                iip->ili_format.ilf_dsize =
+                                        xfs_inode_item_format_extents(ip, vecp,
+                                                XFS_DATA_FORK, XLOG_REG_TYPE_IEXT);
+                                ASSERT(iip->ili_format.ilf_dsize <= ip->i_df.if_bytes);
                         }
-                        ASSERT(vecp->i_len <= ip->i_df.if_bytes);
-                        iip->ili_format.ilf_dsize = vecp->i_len;
-                        vecp++;
                         (*nvecs)++;
                 } else {
                         iip->ili_fields &= ~XFS_ILOG_DEXT;
@@ -262,10 +264,9 @@ xfs_inode_item_format_data_fork(
                 if ((iip->ili_fields & XFS_ILOG_DBROOT) &&
                     ip->i_df.if_broot_bytes > 0) {
                         ASSERT(ip->i_df.if_broot != NULL);
-                        vecp->i_addr = ip->i_df.if_broot;
-                        vecp->i_len = ip->i_df.if_broot_bytes;
-                        vecp->i_type = XLOG_REG_TYPE_IBROOT;
-                        vecp++;
+                        xlog_copy_iovec(vecp, XLOG_REG_TYPE_IBROOT,
+                                        ip->i_df.if_broot,
+                                        ip->i_df.if_broot_bytes);
                         (*nvecs)++;
                         iip->ili_format.ilf_dsize = ip->i_df.if_broot_bytes;
                 } else {
@@ -280,21 +281,18 @@ xfs_inode_item_format_data_fork(
                           XFS_ILOG_DEV | XFS_ILOG_UUID);
                 if ((iip->ili_fields & XFS_ILOG_DDATA) &&
                     ip->i_df.if_bytes > 0) {
-                        ASSERT(ip->i_df.if_u1.if_data != NULL);
-                        ASSERT(ip->i_d.di_size > 0);
-
-                        vecp->i_addr = ip->i_df.if_u1.if_data;
                         /*
                          * Round i_bytes up to a word boundary.
                          * The underlying memory is guaranteed to
                          * to be there by xfs_idata_realloc().
                          */
                         data_bytes = roundup(ip->i_df.if_bytes, 4);
-                        ASSERT((ip->i_df.if_real_bytes == 0) ||
-                               (ip->i_df.if_real_bytes == data_bytes));
-                        vecp->i_len = (int)data_bytes;
-                        vecp->i_type = XLOG_REG_TYPE_ILOCAL;
-                        vecp++;
+                        ASSERT(ip->i_df.if_real_bytes == 0 ||
+                               ip->i_df.if_real_bytes == data_bytes);
+                        ASSERT(ip->i_df.if_u1.if_data != NULL);
+                        ASSERT(ip->i_d.di_size > 0);
+                        xlog_copy_iovec(vecp, XLOG_REG_TYPE_ILOCAL,
+                                        ip->i_df.if_u1.if_data, data_bytes);
                         (*nvecs)++;
                         iip->ili_format.ilf_dsize = (unsigned)data_bytes;
                 } else {
@@ -323,14 +321,12 @@ xfs_inode_item_format_data_fork(
                 ASSERT(0);
                 break;
         }
-
-        return vecp;
 }
 
-STATIC struct xfs_log_iovec *
+STATIC void
 xfs_inode_item_format_attr_fork(
         struct xfs_inode_log_item *iip,
-        struct xfs_log_iovec    *vecp,
+        struct xfs_log_iovec    **vecp,
         int                     *nvecs)
 {
         struct xfs_inode        *ip = iip->ili_inode;
@@ -352,16 +348,16 @@ xfs_inode_item_format_attr_fork(
                          * There are not delayed allocation extents
                          * for attributes, so just point at the array.
                          */
-                        vecp->i_addr = ip->i_afp->if_u1.if_extents;
-                        vecp->i_len = ip->i_afp->if_bytes;
-                        vecp->i_type = XLOG_REG_TYPE_IATTR_EXT;
+                        xlog_copy_iovec(vecp, XLOG_REG_TYPE_IATTR_EXT,
+                                        ip->i_afp->if_u1.if_extents,
+                                        ip->i_afp->if_bytes);
+                        iip->ili_format.ilf_asize = ip->i_afp->if_bytes;
 #else
                         ASSERT(iip->ili_aextents_buf == NULL);
-                        xfs_inode_item_format_extents(ip, vecp,
+                        iip->ili_format.ilf_asize =
+                                xfs_inode_item_format_extents(ip, vecp,
                                         XFS_ATTR_FORK, XLOG_REG_TYPE_IATTR_EXT);
 #endif
-                        iip->ili_format.ilf_asize = vecp->i_len;
-                        vecp++;
                         (*nvecs)++;
                 } else {
                         iip->ili_fields &= ~XFS_ILOG_AEXT;
@@ -375,10 +371,9 @@ xfs_inode_item_format_attr_fork(
                     ip->i_afp->if_broot_bytes > 0) {
                         ASSERT(ip->i_afp->if_broot != NULL);
 
-                        vecp->i_addr = ip->i_afp->if_broot;
-                        vecp->i_len = ip->i_afp->if_broot_bytes;
-                        vecp->i_type = XLOG_REG_TYPE_IATTR_BROOT;
-                        vecp++;
+                        xlog_copy_iovec(vecp, XLOG_REG_TYPE_IATTR_BROOT,
+                                        ip->i_afp->if_broot,
+                                        ip->i_afp->if_broot_bytes);
                         (*nvecs)++;
                         iip->ili_format.ilf_asize = ip->i_afp->if_broot_bytes;
                 } else {
@@ -391,20 +386,18 @@ xfs_inode_item_format_attr_fork(
 
                 if ((iip->ili_fields & XFS_ILOG_ADATA) &&
                     ip->i_afp->if_bytes > 0) {
-                        ASSERT(ip->i_afp->if_u1.if_data != NULL);
-
-                        vecp->i_addr = ip->i_afp->if_u1.if_data;
                         /*
                          * Round i_bytes up to a word boundary.
                          * The underlying memory is guaranteed to
                          * to be there by xfs_idata_realloc().
                          */
                         data_bytes = roundup(ip->i_afp->if_bytes, 4);
-                        ASSERT((ip->i_afp->if_real_bytes == 0) ||
-                               (ip->i_afp->if_real_bytes == data_bytes));
-                        vecp->i_len = (int)data_bytes;
-                        vecp->i_type = XLOG_REG_TYPE_IATTR_LOCAL;
-                        vecp++;
+                        ASSERT(ip->i_afp->if_real_bytes == 0 ||
+                               ip->i_afp->if_real_bytes == data_bytes);
+                        ASSERT(ip->i_afp->if_u1.if_data != NULL);
+                        xlog_copy_iovec(vecp, XLOG_REG_TYPE_IATTR_LOCAL,
+                                        ip->i_afp->if_u1.if_data,
+                                        data_bytes);
                         (*nvecs)++;
                         iip->ili_format.ilf_asize = (unsigned)data_bytes;
                 } else {
@@ -415,8 +408,6 @@ xfs_inode_item_format_attr_fork(
                 ASSERT(0);
                 break;
         }
-
-        return vecp;
 }
 
 /*
@@ -435,24 +426,22 @@ xfs_inode_item_format(
         struct xfs_inode        *ip = iip->ili_inode;
         uint                    nvecs;
 
-        vecp->i_addr = &iip->ili_format;
-        vecp->i_len  = sizeof(xfs_inode_log_format_t);
-        vecp->i_type = XLOG_REG_TYPE_IFORMAT;
-        vecp++;
-        nvecs        = 1;
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_IFORMAT,
+                        &iip->ili_format,
+                        sizeof(struct xfs_inode_log_format));
+        nvecs = 1;
 
-        vecp->i_addr = &ip->i_d;
-        vecp->i_len  = xfs_icdinode_size(ip->i_d.di_version);
-        vecp->i_type = XLOG_REG_TYPE_ICORE;
-        vecp++;
+        xlog_copy_iovec(&vecp, XLOG_REG_TYPE_ICORE,
+                        &ip->i_d,
+                        xfs_icdinode_size(ip->i_d.di_version));
         nvecs++;
 
         if (ip->i_d.di_version == 1)
                 xfs_inode_item_format_v1_inode(ip);
 
-        vecp = xfs_inode_item_format_data_fork(iip, vecp, &nvecs);
+        xfs_inode_item_format_data_fork(iip, &vecp, &nvecs);
         if (XFS_IFORK_Q(ip)) {
-                vecp = xfs_inode_item_format_attr_fork(iip, vecp, &nvecs);
+                xfs_inode_item_format_attr_fork(iip, &vecp, &nvecs);
         } else {
                 iip->ili_fields &=
                         ~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT);
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index e148719e0a5d..384c6c469661 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -30,6 +30,19 @@ struct xfs_log_vec {
 
 #define XFS_LOG_VEC_ORDERED     (-1)
 
+static inline void *
+xlog_copy_iovec(struct xfs_log_iovec **vecp, uint type, void *data, int len)
+{
+        struct xfs_log_iovec *vec = *vecp;
+
+        vec->i_type = type;
+        vec->i_addr = data;
+        vec->i_len = len;
+
+        *vecp = vec + 1;
+        return vec->i_addr;
+}
+
 /*
  * Structure used to pass callback function and the function's argument
  * to the log manager.