diff options
Diffstat (limited to 'fs/ocfs2/refcounttree.c')
| -rw-r--r-- | fs/ocfs2/refcounttree.c | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index 0a92436557e..37aa0c8696d 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -2482,6 +2482,7 @@ static inline unsigned int ocfs2_cow_align_length(struct super_block *sb, * * cpos is vitual start cluster position we want to do CoW in a * file and write_len is the cluster length. + * max_cpos is the place where we want to stop CoW intentionally. * * Normal we will start CoW from the beginning of extent record cotaining cpos. * We try to break up extents on boundaries of MAX_CONTIG_BYTES so that we @@ -2491,6 +2492,7 @@ static int ocfs2_refcount_cal_cow_clusters(struct inode *inode, struct buffer_head *di_bh, u32 cpos, u32 write_len, + u32 max_cpos, u32 *cow_start, u32 *cow_len) { @@ -2505,6 +2507,8 @@ static int ocfs2_refcount_cal_cow_clusters(struct inode *inode, int contig_clusters = ocfs2_cow_contig_clusters(inode->i_sb); int leaf_clusters; + BUG_ON(cpos + write_len > max_cpos); + if (tree_height > 0) { ret = ocfs2_find_leaf(INODE_CACHE(inode), el, cpos, &eb_bh); if (ret) { @@ -2549,15 +2553,20 @@ static int ocfs2_refcount_cal_cow_clusters(struct inode *inode, } /* - * If we encounter a hole or a non-refcounted record, - * stop the search. + * If we encounter a hole, a non-refcounted record or + * pass the max_cpos, stop the search. */ if ((!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) || - (*cow_len && rec_end != le32_to_cpu(rec->e_cpos))) + (*cow_len && rec_end != le32_to_cpu(rec->e_cpos)) || + (max_cpos <= le32_to_cpu(rec->e_cpos))) break; leaf_clusters = le16_to_cpu(rec->e_leaf_clusters); rec_end = le32_to_cpu(rec->e_cpos) + leaf_clusters; + if (rec_end > max_cpos) { + rec_end = max_cpos; + leaf_clusters = rec_end - le32_to_cpu(rec->e_cpos); + } /* * How many clusters do we actually need from @@ -3184,12 +3193,13 @@ static int ocfs2_replace_cow(struct inode *inode, } /* - * Starting at cpos, try to CoW write_len clusters. - * This will stop when it runs into a hole or an unrefcounted extent. + * Starting at cpos, try to CoW write_len clusters. Don't CoW + * past max_cpos. This will stop when it runs into a hole or an + * unrefcounted extent. */ static int ocfs2_refcount_cow_hunk(struct inode *inode, struct buffer_head *di_bh, - u32 cpos, u32 write_len) + u32 cpos, u32 write_len, u32 max_cpos) { int ret; u32 cow_start = 0, cow_len = 0; @@ -3201,12 +3211,14 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode, BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)); - ret = ocfs2_refcount_cal_cow_clusters(inode, di_bh, cpos, write_len, + ret = ocfs2_refcount_cal_cow_clusters(inode, di_bh, + cpos, write_len, max_cpos, &cow_start, &cow_len); if (ret) { mlog_errno(ret); goto out; } + mlog(0, "CoW inode %lu, cpos %u, write_len %u, cow_start %u, " "cow_len %u\n", inode->i_ino, cpos, write_len, cow_start, cow_len); @@ -3233,12 +3245,12 @@ out: /* * CoW any and all clusters between cpos and cpos+write_len. - * If this returns successfully, all clusters between cpos and - * cpos+write_len are safe to modify. + * Don't CoW past max_cpos. If this returns successfully, all + * clusters between cpos and cpos+write_len are safe to modify. */ int ocfs2_refcount_cow(struct inode *inode, struct buffer_head *di_bh, - u32 cpos, u32 write_len) + u32 cpos, u32 write_len, u32 max_cpos) { int ret = 0; u32 p_cluster, num_clusters; @@ -3257,7 +3269,7 @@ int ocfs2_refcount_cow(struct inode *inode, if (ext_flags & OCFS2_EXT_REFCOUNTED) { ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos, - num_clusters); + num_clusters, max_cpos); if (ret) { mlog_errno(ret); break; |