ocfs2: Increase max links count

Since we've now got a directory format capable of handling a large number of
entries, we can increase the maximum link count supported. This only gets
increased if the directory indexing feature is turned on.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>

4 files changed, 66 insertions, 26 deletions

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index d273c4a51a0..f1f77b2f594 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -276,7 +276,7 @@ void ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
                      (unsigned long long)OCFS2_I(inode)->ip_blkno,
                      (unsigned long long)le64_to_cpu(fe->i_blkno));
 
-        inode->i_nlink = le16_to_cpu(fe->i_links_count);
+        inode->i_nlink = ocfs2_read_links_count(fe);
 
         if (fe->i_flags & cpu_to_le32(OCFS2_SYSTEM_FL)) {
                 OCFS2_I(inode)->ip_flags |= OCFS2_INODE_SYSTEM_FILE;
@@ -1215,7 +1215,7 @@ int ocfs2_mark_inode_dirty(handle_t *handle,
         spin_unlock(&OCFS2_I(inode)->ip_lock);
 
         fe->i_size = cpu_to_le64(i_size_read(inode));
-        fe->i_links_count = cpu_to_le16(inode->i_nlink);
+        ocfs2_set_links_count(fe, inode->i_nlink);
         fe->i_uid = cpu_to_le32(inode->i_uid);
         fe->i_gid = cpu_to_le32(inode->i_gid);
         fe->i_mode = cpu_to_le16(inode->i_mode);
@@ -1252,7 +1252,7 @@ void ocfs2_refresh_inode(struct inode *inode,
         OCFS2_I(inode)->ip_dyn_features = le16_to_cpu(fe->i_dyn_features);
         ocfs2_set_inode_flags(inode);
         i_size_write(inode, le64_to_cpu(fe->i_size));
-        inode->i_nlink = le16_to_cpu(fe->i_links_count);
+        inode->i_nlink = ocfs2_read_links_count(fe);
         inode->i_uid = le32_to_cpu(fe->i_uid);
         inode->i_gid = le32_to_cpu(fe->i_gid);
         inode->i_mode = le16_to_cpu(fe->i_mode);
diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index f911edc8378..67113cfddc9 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -255,13 +255,13 @@ static int ocfs2_mknod(struct inode *dir,
                 return status;
         }
 
-        if (S_ISDIR(mode) && (dir->i_nlink >= OCFS2_LINK_MAX)) {
+        if (S_ISDIR(mode) && (dir->i_nlink >= ocfs2_link_max(osb))) {
                 status = -EMLINK;
                 goto leave;
         }
 
         dirfe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
-        if (!dirfe->i_links_count) {
+        if (!ocfs2_read_links_count(dirfe)) {
                 /* can't make a file in a deleted directory. */
                 status = -ENOENT;
                 goto leave;
@@ -381,7 +381,7 @@ static int ocfs2_mknod(struct inode *dir,
                         mlog_errno(status);
                         goto leave;
                 }
-                le16_add_cpu(&dirfe->i_links_count, 1);
+                ocfs2_add_links_count(dirfe, 1);
                 status = ocfs2_journal_dirty(handle, parent_fe_bh);
                 if (status < 0) {
                         mlog_errno(status);
@@ -529,7 +529,8 @@ static int ocfs2_mknod_locked(struct ocfs2_super *osb,
         fe->i_mode = cpu_to_le16(inode->i_mode);
         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
                 fe->id1.dev1.i_rdev = cpu_to_le64(huge_encode_dev(dev));
-        fe->i_links_count = cpu_to_le16(inode->i_nlink);
+
+        ocfs2_set_links_count(fe, inode->i_nlink);
 
         fe->i_last_eb_blk = 0;
         strcpy(fe->i_signature, OCFS2_INODE_SIGNATURE);
@@ -668,7 +669,7 @@ static int ocfs2_link(struct dentry *old_dentry,
         }
 
         fe = (struct ocfs2_dinode *) fe_bh->b_data;
-        if (le16_to_cpu(fe->i_links_count) >= OCFS2_LINK_MAX) {
+        if (ocfs2_read_links_count(fe) >= ocfs2_link_max(osb)) {
                 err = -EMLINK;
                 goto out_unlock_inode;
         }
@@ -690,13 +691,13 @@ static int ocfs2_link(struct dentry *old_dentry,
 
         inc_nlink(inode);
         inode->i_ctime = CURRENT_TIME;
-        fe->i_links_count = cpu_to_le16(inode->i_nlink);
+        ocfs2_set_links_count(fe, inode->i_nlink);
         fe->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
         fe->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 
         err = ocfs2_journal_dirty(handle, fe_bh);
         if (err < 0) {
-                le16_add_cpu(&fe->i_links_count, -1);
+                ocfs2_add_links_count(fe, -1);
                 drop_nlink(inode);
                 mlog_errno(err);
                 goto out_commit;
@@ -706,7 +707,7 @@ static int ocfs2_link(struct dentry *old_dentry,
                               OCFS2_I(inode)->ip_blkno,
                               parent_fe_bh, &lookup);
         if (err) {
-                le16_add_cpu(&fe->i_links_count, -1);
+                ocfs2_add_links_count(fe, -1);
                 drop_nlink(inode);
                 mlog_errno(err);
                 goto out_commit;
@@ -895,7 +896,7 @@ static int ocfs2_unlink(struct inode *dir,
         if (S_ISDIR(inode->i_mode))
                 drop_nlink(inode);
         drop_nlink(inode);
-        fe->i_links_count = cpu_to_le16(inode->i_nlink);
+        ocfs2_set_links_count(fe, inode->i_nlink);
 
         status = ocfs2_journal_dirty(handle, fe_bh);
         if (status < 0) {
@@ -1139,7 +1140,7 @@ static int ocfs2_rename(struct inode *old_dir,
                 }
 
                 if (!new_inode && new_dir != old_dir &&
-                    new_dir->i_nlink >= OCFS2_LINK_MAX) {
+                    new_dir->i_nlink >= ocfs2_link_max(osb)) {
                         status = -EMLINK;
                         goto bail;
                 }
@@ -1293,7 +1294,7 @@ static int ocfs2_rename(struct inode *old_dir,
                 }
 
                 if (S_ISDIR(new_inode->i_mode) ||
-                    (newfe->i_links_count == cpu_to_le16(1))){
+                    (ocfs2_read_links_count(newfe) == 1)) {
                         status = ocfs2_orphan_add(osb, handle, new_inode,
                                                   newfe, orphan_name,
                                                   &orphan_insert, orphan_dir);
@@ -1313,9 +1314,9 @@ static int ocfs2_rename(struct inode *old_dir,
                 new_dir->i_version++;
 
                 if (S_ISDIR(new_inode->i_mode))
-                        newfe->i_links_count = 0;
+                        ocfs2_set_links_count(newfe, 0);
                 else
-                        le16_add_cpu(&newfe->i_links_count, -1);
+                        ocfs2_add_links_count(newfe, -1);
 
                 status = ocfs2_journal_dirty(handle, newfe_bh);
                 if (status < 0) {
@@ -1409,14 +1410,13 @@ static int ocfs2_rename(struct inode *old_dir,
                 } else {
                         struct ocfs2_dinode *fe;
                         status = ocfs2_journal_access_di(handle, old_dir,
-                                                         old_dir_bh,
-                                                         OCFS2_JOURNAL_ACCESS_WRITE);
+                                                      old_dir_bh,
+                                                      OCFS2_JOURNAL_ACCESS_WRITE);
                         fe = (struct ocfs2_dinode *) old_dir_bh->b_data;
-                        fe->i_links_count = cpu_to_le16(old_dir->i_nlink);
+                        ocfs2_set_links_count(fe, old_dir->i_nlink);
                         status = ocfs2_journal_dirty(handle, old_dir_bh);
                 }
         }
-
         ocfs2_dentry_move(old_dentry, new_dentry, old_dir, new_dir);
         status = 0;
 bail:
@@ -1614,7 +1614,7 @@ static int ocfs2_symlink(struct inode *dir,
         }
 
         dirfe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
-        if (!dirfe->i_links_count) {
+        if (!ocfs2_read_links_count(dirfe)) {
                 /* can't make a file in a deleted directory. */
                 status = -ENOENT;
                 goto bail;
@@ -1932,8 +1932,8 @@ static int ocfs2_orphan_add(struct ocfs2_super *osb,
          * underneath us... */
         orphan_fe = (struct ocfs2_dinode *) orphan_dir_bh->b_data;
         if (S_ISDIR(inode->i_mode))
-                le16_add_cpu(&orphan_fe->i_links_count, 1);
-        orphan_dir_inode->i_nlink = le16_to_cpu(orphan_fe->i_links_count);
+                ocfs2_add_links_count(orphan_fe, 1);
+        orphan_dir_inode->i_nlink = ocfs2_read_links_count(orphan_fe);
 
         status = ocfs2_journal_dirty(handle, orphan_dir_bh);
         if (status < 0) {
@@ -2016,8 +2016,8 @@ int ocfs2_orphan_del(struct ocfs2_super *osb,
         /* do the i_nlink dance! :) */
         orphan_fe = (struct ocfs2_dinode *) orphan_dir_bh->b_data;
         if (S_ISDIR(inode->i_mode))
-                le16_add_cpu(&orphan_fe->i_links_count, -1);
-        orphan_dir_inode->i_nlink = le16_to_cpu(orphan_fe->i_links_count);
+                ocfs2_add_links_count(orphan_fe, -1);
+        orphan_dir_inode->i_nlink = ocfs2_read_links_count(orphan_fe);
 
         status = ocfs2_journal_dirty(handle, orphan_dir_bh);
         if (status < 0) {
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 3749c32c2fc..fa3c6d3f0bd 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -408,6 +408,44 @@ static inline int ocfs2_supports_indexed_dirs(struct ocfs2_super *osb)
         return 0;
 }
 
+static inline unsigned int ocfs2_link_max(struct ocfs2_super *osb)
+{
+        if (ocfs2_supports_indexed_dirs(osb))
+                return OCFS2_DX_LINK_MAX;
+        return OCFS2_LINK_MAX;
+}
+
+static inline unsigned int ocfs2_read_links_count(struct ocfs2_dinode *di)
+{
+        u32 nlink = le16_to_cpu(di->i_links_count);
+        u32 hi = le16_to_cpu(di->i_links_count_hi);
+
+        if (di->i_dyn_features & cpu_to_le16(OCFS2_INDEXED_DIR_FL))
+                nlink |= (hi << OCFS2_LINKS_HI_SHIFT);
+
+        return nlink;
+}
+
+static inline void ocfs2_set_links_count(struct ocfs2_dinode *di, u32 nlink)
+{
+        u16 lo, hi;
+
+        lo = nlink;
+        hi = nlink >> OCFS2_LINKS_HI_SHIFT;
+
+        di->i_links_count = cpu_to_le16(lo);
+        di->i_links_count_hi = cpu_to_le16(hi);
+}
+
+static inline void ocfs2_add_links_count(struct ocfs2_dinode *di, int n)
+{
+        u32 links = ocfs2_read_links_count(di);
+
+        links += n;
+
+        ocfs2_set_links_count(di, links);
+}
+
 /* set / clear functions because cluster events can make these happen
  * in parallel so we want the transitions to be atomic. this also
  * means that any future flags osb_flags must be protected by spinlock
diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index d549b1799a6..43da76eff9a 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -419,6 +419,8 @@ static struct ocfs2_system_inode_info ocfs2_system_inodes[NUM_SYSTEM_INODES] = {
 #define OCFS2_DIR_MIN_REC_LEN   OCFS2_DIR_REC_LEN(1)
 
 #define OCFS2_LINK_MAX          32000
+#define OCFS2_DX_LINK_MAX       ((1U << 31) - 1U)
+#define OCFS2_LINKS_HI_SHIFT    16
 
 #define S_SHIFT                 12
 static unsigned char ocfs2_type_by_mode[S_IFMT >> S_SHIFT] = {
@@ -686,7 +688,7 @@ struct ocfs2_dinode {
                                            belongs to */
         __le16 i_suballoc_bit;          /* Bit offset in suballocator
                                            block group */
-/*10*/  __le16 i_reserved0;
+/*10*/  __le16 i_links_count_hi;        /* High 16 bits of links count */
         __le16 i_xattr_inline_size;
         __le32 i_clusters;              /* Cluster count */
         __le32 i_uid;                   /* Owner UID */