[RFC v2 50/83] Inode: Add nova_evict_inode.

Andiry Xu
2018-03-10T18:32:22Z

If the inode still have links, release the DRAM resource (radix tree, etc).
Otherwise reclaim data pages and log pages.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
fs/nova/inode.c | 257 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
fs/nova/inode.h | 5 ++
fs/nova/log.h | 7 ++
fs/nova/super.c | 1 +
4 files changed, 269 insertions(+), 1 deletion(-)

diff --git a/fs/nova/inode.c b/fs/nova/inode.c
index 41417e3..17addd3 100644
--- a/fs/nova/inode.c
+++ b/fs/nova/inode.c
@@ -457,7 +457,7 @@ static int nova_alloc_unused_inode(struct super_block *sb, int cpuid,
return 0;
}

-int nova_free_inuse_inode(struct super_block *sb, unsigned long ino)
+static int nova_free_inuse_inode(struct super_block *sb, unsigned long ino)
{
struct nova_sb_info *sbi = NOVA_SB(sb);
struct inode_map *inode_map;
@@ -532,6 +532,261 @@ int nova_free_inuse_inode(struct super_block *sb, unsigned long ino)
return ret;
}

+static int nova_free_inode(struct super_block *sb, struct nova_inode *pi,
+ struct nova_inode_info_header *sih)
+{
+ int err = 0;
+ timing_t free_time;
+
+ NOVA_START_TIMING(free_inode_t, free_time);
+
+ nova_free_inode_log(sb, pi, sih);
+
+ sih->log_pages = 0;
+ sih->i_mode = 0;
+ sih->pi_addr = 0;
+ sih->i_size = 0;
+ sih->i_blocks = 0;
+
+ err = nova_free_inuse_inode(sb, pi->nova_ino);
+
+ NOVA_END_TIMING(free_inode_t, free_time);
+ return err;
+}
+
+/*
+ * We do not really rely on this last blocknr
+ * because blocks can be allocated beyond file end
+ */
+static unsigned long nova_get_last_blocknr(struct super_block *sb,
+ struct nova_inode_info_header *sih)
+{
+ struct nova_inode *pi, fake_pi;
+ unsigned long last_blocknr;
+ unsigned int btype;
+ unsigned int data_bits;
+ int ret;
+
+ ret = nova_get_reference(sb, sih->pi_addr, &fake_pi,
+ (void **)&pi, sizeof(struct nova_inode));
+ if (ret) {
+ nova_dbg("%s: read pi @ 0x%lx failed\n",
+ __func__, sih->pi_addr);
+ btype = 0;
+ } else {
+ btype = sih->i_blk_type;
+ }
+
+ data_bits = blk_type_to_shift[btype];
+
+ if (sih->i_size == 0)
+ last_blocknr = 0;
+ else
+ last_blocknr = (sih->i_size - 1) >> data_bits;
+
+ return last_blocknr;
+}
+
+int nova_delete_file_tree(struct super_block *sb,
+ struct nova_inode_info_header *sih, unsigned long start_blocknr,
+ unsigned long last_blocknr, bool delete_nvmm, bool delete_dead,
+ u64 epoch_id)
+{
+ struct nova_file_write_entry *entry;
+ struct nova_file_write_entry *old_entry = NULL;
+ unsigned long pgoff = start_blocknr;
+ unsigned long old_pgoff = 0;
+ unsigned int num_free = 0;
+ int freed = 0;
+ void *ret;
+ timing_t delete_time;
+
+ NOVA_START_TIMING(delete_file_tree_t, delete_time);
+
+ /* Handle EOF blocks */
+ do {
+ entry = radix_tree_lookup(&sih->tree, pgoff);
+ if (entry) {
+ ret = radix_tree_delete(&sih->tree, pgoff);
+ WARN_ON(!ret || ret != entry);
+ if (entry != old_entry) {
+ if (old_entry && delete_nvmm) {
+ nova_free_old_entry(sb, sih,
+ old_entry, old_pgoff,
+ num_free, delete_dead,
+ epoch_id);
+ freed += num_free;
+ }
+
+ old_entry = entry;
+ old_pgoff = pgoff;
+ num_free = 1;
+ } else {
+ num_free++;
+ }
+ pgoff++;
+ } else {
+ /* We are finding a hole. Jump to the next entry. */
+ entry = nova_find_next_entry(sb, sih, pgoff);
+ if (!entry)
+ break;
+
+ pgoff++;
+ pgoff = pgoff > entry->pgoff ? pgoff : entry->pgoff;
+ }
+ } while (1);
+
+ if (old_entry && delete_nvmm) {
+ nova_free_old_entry(sb, sih, old_entry, old_pgoff,
+ num_free, delete_dead, epoch_id);
+ freed += num_free;
+ }
+
+ nova_dbgv("Inode %lu: delete file tree from pgoff %lu to %lu, %d blocks freed\n",
+ sih->ino, start_blocknr, last_blocknr, freed);
+
+ NOVA_END_TIMING(delete_file_tree_t, delete_time);
+ return freed;
+}
+
+static int nova_free_dram_resource(struct super_block *sb,
+ struct nova_inode_info_header *sih)
+{
+ unsigned long last_blocknr;
+ int freed = 0;
+
+ if (sih->ino == 0)
+ return 0;
+
+ if (!(S_ISREG(sih->i_mode)) && !(S_ISDIR(sih->i_mode)))
+ return 0;
+
+ if (S_ISREG(sih->i_mode)) {
+ last_blocknr = nova_get_last_blocknr(sb, sih);
+ freed = nova_delete_file_tree(sb, sih, 0,
+ last_blocknr, false, false, 0);
+ } else {
+ nova_delete_dir_tree(sb, sih);
+ freed = 1;
+ }
+
+ return freed;
+}
+
+static int nova_free_inode_resource(struct super_block *sb,
+ struct nova_inode *pi, struct nova_inode_info_header *sih)
+{
+ unsigned long last_blocknr;
+ int ret = 0;
+ int freed = 0;
+
+ pi->deleted = 1;
+
+ if (pi->valid) {
+ nova_dbg("%s: inode %lu still valid\n",
+ __func__, sih->ino);
+ pi->valid = 0;
+ }
+ nova_persist_inode(pi);
+
+ /* We need the log to free the blocks from the b-tree */
+ switch (__le16_to_cpu(pi->i_mode) & S_IFMT) {
+ case S_IFREG:
+ last_blocknr = nova_get_last_blocknr(sb, sih);
+ nova_dbgv("%s: file ino %lu\n", __func__, sih->ino);
+ freed = nova_delete_file_tree(sb, sih, 0,
+ last_blocknr, true, true, 0);
+ break;
+ case S_IFDIR:
+ nova_dbgv("%s: dir ino %lu\n", __func__, sih->ino);
+ nova_delete_dir_tree(sb, sih);
+ break;
+ case S_IFLNK:
+ /* Log will be freed later */
+ nova_dbgv("%s: symlink ino %lu\n",
+ __func__, sih->ino);
+ freed = nova_delete_file_tree(sb, sih, 0, 0,
+ true, true, 0);
+ break;
+ default:
+ nova_dbgv("%s: special ino %lu\n",
+ __func__, sih->ino);
+ break;
+ }
+
+ nova_dbg_verbose("%s: Freed %d\n", __func__, freed);
+ /* Then we can free the inode */
+ ret = nova_free_inode(sb, pi, sih);
+ if (ret)
+ nova_err(sb, "%s: free inode %lu failed\n",
+ __func__, sih->ino);
+
+ return ret;
+}
+
+void nova_evict_inode(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct nova_inode *pi = nova_get_inode(sb, inode);
+ struct nova_inode_info *si = NOVA_I(inode);
+ struct nova_inode_info_header *sih = &si->header;
+ timing_t evict_time;
+ int destroy = 0;
+ int ret;
+
+ NOVA_START_TIMING(evict_inode_t, evict_time);
+ if (!sih) {
+ nova_err(sb, "%s: ino %lu sih is NULL!\n",
+ __func__, inode->i_ino);
+ NOVA_ASSERT(0);
+ goto out;
+ }
+
+ // pi can be NULL if the file has already been deleted, but a handle
+ // remains.
+ if (pi && pi->nova_ino != inode->i_ino) {
+ nova_err(sb, "%s: inode %lu ino does not match: %llu\n",
+ __func__, inode->i_ino, pi->nova_ino);
+ nova_dbg("inode size %llu, pi addr 0x%lx, pi head 0x%llx, tail 0x%llx, mode %u\n",
+ inode->i_size, sih->pi_addr, sih->log_head,
+ sih->log_tail, pi->i_mode);
+ nova_dbg("sih: ino %lu, inode size %lu, mode %u, inode mode %u\n",
+ sih->ino, sih->i_size,
+ sih->i_mode, inode->i_mode);
+ nova_print_inode_log(sb, inode);
+ }
+
+ nova_dbg_verbose("%s: %lu\n", __func__, inode->i_ino);
+ if (!inode->i_nlink && !is_bad_inode(inode)) {
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ goto out;
+
+ if (pi) {
+ ret = nova_free_inode_resource(sb, pi, sih);
+ if (ret)
+ goto out;
+ }
+
+ destroy = 1;
+ pi = NULL; /* we no longer own the nova_inode */
+
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+ inode->i_size = 0;
+ }
+out:
+ if (destroy == 0) {
+ nova_dbgv("%s: destroying %lu\n", __func__, inode->i_ino);
+ nova_free_dram_resource(sb, sih);
+ }
+ /* TODO: Since we don't use page-cache, do we really need the following
+ * call?
+ */
+ truncate_inode_pages(&inode->i_data, 0);
+
+ clear_inode(inode);
+ NOVA_END_TIMING(evict_inode_t, evict_time);
+}
+
/* Returns 0 on failure */
u64 nova_new_nova_inode(struct super_block *sb, u64 *pi_addr)
{
diff --git a/fs/nova/inode.h b/fs/nova/inode.h
index 6970872..62c8bdc 100644
--- a/fs/nova/inode.h
+++ b/fs/nova/inode.h
@@ -245,6 +245,11 @@ u64 nova_new_nova_inode(struct super_block *sb, u64 *pi_addr);
struct inode *nova_new_vfs_inode(enum nova_new_inode_type type,
struct inode *dir, u64 pi_addr, u64 ino, umode_t mode,
size_t size, dev_t rdev, const struct qstr *qstr, u64 epoch_id);
+int nova_delete_file_tree(struct super_block *sb,
+ struct nova_inode_info_header *sih, unsigned long start_blocknr,
+ unsigned long last_blocknr, bool delete_nvmm, bool delete_dead,
+ u64 epoch_id);
+extern void nova_evict_inode(struct inode *inode);
extern int nova_write_inode(struct inode *inode, struct writeback_control *wbc);
extern void nova_dirty_inode(struct inode *inode, int flags);

diff --git a/fs/nova/log.h b/fs/nova/log.h
index f5149f7..87ce5f9 100644
--- a/fs/nova/log.h
+++ b/fs/nova/log.h
@@ -364,6 +364,13 @@ static inline int is_dir_init_entry(struct super_block *sb,
}

+unsigned int nova_free_old_entry(struct super_block *sb,
+ struct nova_inode_info_header *sih,
+ struct nova_file_write_entry *entry,
+ unsigned long pgoff, unsigned int num_free,
+ bool delete_dead, u64 epoch_id);
+struct nova_file_write_entry *nova_find_next_entry(struct super_block *sb,
+ struct nova_inode_info_header *sih, pgoff_t pgoff);
int nova_handle_setattr_operation(struct super_block *sb, struct inode *inode,
struct nova_inode *pi, unsigned int ia_valid, struct iattr *attr,
u64 epoch_id);
diff --git a/fs/nova/super.c b/fs/nova/super.c
index 1e67062..daf3270 100644
--- a/fs/nova/super.c
+++ b/fs/nova/super.c
@@ -884,6 +884,7 @@ static struct super_operations nova_sops = {
.destroy_inode = nova_destroy_inode,
.write_inode = nova_write_inode,
.dirty_inode = nova_dirty_inode,
+ .evict_inode = nova_evict_inode,
.put_super = nova_put_super,
.statfs = nova_statfs,
.remount_fs = nova_remount,
--
2.7.4