ext4: main fast-commit commit path
This patch adds main fast commit commit path handlers. The overall
patch can be divided into two inter-related parts:
(A) Metadata updates tracking
This part consists of helper functions to track changes that need
to be committed during a commit operation. These updates are
maintained by Ext4 in different in-memory queues. Following are
the APIs and their short description that are implemented in this
patch:
- ext4_fc_track_link/unlink/creat() - Track unlink. link and creat
operations
- ext4_fc_track_range() - Track changed logical block offsets
inodes
- ext4_fc_track_inode() - Track inodes
- ext4_fc_mark_ineligible() - Mark file system fast commit
ineligible()
- ext4_fc_start_update() / ext4_fc_stop_update() /
ext4_fc_start_ineligible() / ext4_fc_stop_ineligible() These
functions are useful for co-ordinating inode updates with
commits.
(B) Main commit Path
This part consists of functions to convert updates tracked in
in-memory data structures into on-disk commits. Function
ext4_fc_commit() is the main entry point to commit path.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-6-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 701ef9f..fd7be14 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2611,7 +2611,7 @@ static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
handle_t *handle;
- struct inode *inode;
+ struct inode *inode, *inode_save;
int err, credits, retries = 0;
err = dquot_initialize(dir);
@@ -2629,7 +2629,11 @@ static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
ext4_set_aops(inode);
+ inode_save = inode;
+ ihold(inode_save);
err = ext4_add_nondir(handle, dentry, &inode);
+ ext4_fc_track_create(inode_save, dentry);
+ iput(inode_save);
}
if (handle)
ext4_journal_stop(handle);
@@ -2644,7 +2648,7 @@ static int ext4_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
handle_t *handle;
- struct inode *inode;
+ struct inode *inode, *inode_save;
int err, credits, retries = 0;
err = dquot_initialize(dir);
@@ -2661,7 +2665,12 @@ static int ext4_mknod(struct inode *dir, struct dentry *dentry,
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
inode->i_op = &ext4_special_inode_operations;
+ inode_save = inode;
+ ihold(inode_save);
err = ext4_add_nondir(handle, dentry, &inode);
+ if (!err)
+ ext4_fc_track_create(inode_save, dentry);
+ iput(inode_save);
}
if (handle)
ext4_journal_stop(handle);
@@ -2825,7 +2834,9 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
iput(inode);
goto out_retry;
}
+ ext4_fc_track_create(inode, dentry);
ext4_inc_count(dir);
+
ext4_update_dx_flag(dir);
err = ext4_mark_inode_dirty(handle, dir);
if (err)
@@ -3165,6 +3176,7 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
goto end_rmdir;
ext4_dec_count(dir);
ext4_update_dx_flag(dir);
+ ext4_fc_track_unlink(inode, dentry);
retval = ext4_mark_inode_dirty(handle, dir);
#ifdef CONFIG_UNICODE
@@ -3251,6 +3263,8 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
inode->i_ctime = current_time(inode);
retval = ext4_mark_inode_dirty(handle, inode);
+ if (!retval)
+ ext4_fc_track_unlink(d_inode(dentry), dentry);
#ifdef CONFIG_UNICODE
/* VFS negative dentries are incompatible with Encoding and
* Case-insensitiveness. Eventually we'll want avoid
@@ -3872,6 +3886,22 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
retval = ext4_mark_inode_dirty(handle, old.dir);
if (unlikely(retval))
goto end_rename;
+
+ if (S_ISDIR(old.inode->i_mode)) {
+ /*
+ * We disable fast commits here that's because the
+ * replay code is not yet capable of changing dot dot
+ * dirents in directories.
+ */
+ ext4_fc_mark_ineligible(old.inode->i_sb,
+ EXT4_FC_REASON_RENAME_DIR);
+ } else {
+ if (new.inode)
+ ext4_fc_track_unlink(new.inode, new.dentry);
+ ext4_fc_track_link(old.inode, new.dentry);
+ ext4_fc_track_unlink(old.inode, old.dentry);
+ }
+
if (new.inode) {
retval = ext4_mark_inode_dirty(handle, new.inode);
if (unlikely(retval))
@@ -4015,7 +4045,8 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
retval = ext4_mark_inode_dirty(handle, new.inode);
if (unlikely(retval))
goto end_rename;
-
+ ext4_fc_mark_ineligible(new.inode->i_sb,
+ EXT4_FC_REASON_CROSS_RENAME);
if (old.dir_bh) {
retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
if (retval)