LU-12593 osd: zeroing a freshly allocated block buffer

[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_io.c

diff --git a/lustre/osd-ldiskfs/osd_io.c b/lustre/osd-ldiskfs/osd_io.c
index c6a09d3..3503e5a 100644 (file)
--- a/lustre/osd-ldiskfs/osd_io.c
+++ b/lustre/osd-ldiskfs/osd_io.c
@@ -1654,6 +1654,8 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
         int                 size;
         int                 boffs;
         int                 dirty_inode = 0;
+       struct ldiskfs_inode_info *ei = LDISKFS_I(inode);
+       bool create, sparse;
 
        if (write_NUL) {
                /*
@@ -1665,8 +1667,15 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                ++bufsize;
        }
 
+       /* sparse checking is racy, but sparse is very rare case, leave as is */
+       sparse = (new_size > 0 && (inode->i_blocks >> (inode->i_blkbits - 9)) <
+                 ((new_size - 1) >> inode->i_blkbits) + 1);
+
        while (bufsize > 0) {
                int credits = handle->h_buffer_credits;
+               bool sync;
+               unsigned long last_block = (new_size == 0) ? 0 :
+                                          (new_size - 1) >> inode->i_blkbits;
 
                if (bh)
                        brelse(bh);
@@ -1674,7 +1683,26 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                block = offset >> inode->i_blkbits;
                boffs = offset & (blocksize - 1);
                size = min(blocksize - boffs, bufsize);
-               bh = __ldiskfs_bread(handle, inode, block, 1);
+               sync = (block > last_block || new_size == 0 || sparse);
+
+               if (sync)
+                       down(&ei->i_append_sem);
+
+               bh = __ldiskfs_bread(handle, inode, block, 0);
+
+               if (unlikely(IS_ERR_OR_NULL(bh) && !sync))
+                       CWARN("%s: adding bh without locking off %llu (block %lu, "
+                             "size %d, offs %llu)\n", inode->i_sb->s_id,
+                             offset, block, bufsize, *offs);
+
+               if (IS_ERR_OR_NULL(bh)) {
+                       bh = __ldiskfs_bread(handle, inode, block, 1);
+                       create = true;
+               } else {
+                       if (sync)
+                               up(&ei->i_append_sem);
+                       create = false;
+               }
                if (IS_ERR_OR_NULL(bh)) {
                        if (bh == NULL) {
                                err = -EIO;
@@ -1699,7 +1727,12 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                LASSERTF(boffs + size <= bh->b_size,
                         "boffs %d size %d bh->b_size %lu\n",
                         boffs, size, (unsigned long)bh->b_size);
-                memcpy(bh->b_data + boffs, buf, size);
+               if (create) {
+                       memset(bh->b_data, 0, bh->b_size);
+                       if (sync)
+                               up(&ei->i_append_sem);
+               }
+               memcpy(bh->b_data + boffs, buf, size);
                err = ldiskfs_handle_dirty_metadata(handle, NULL, bh);
                 if (err)
                         break;