nilfs2: remove timedwait ioctl command

This removes NILFS_IOCTL_TIMEDWAIT command from ioctl interface along
with the related flags and wait queue.

The command is terrible because it just sleeps in the ioctl.  I prefer
to avoid this by devising means of event polling in userland program.
By reconsidering the userland GC daemon, I found this is possible
without changing behaviour of the daemon and sacrificing efficiency.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 2 insertions, 127 deletions

diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 9e4d9e64c8ff..85a291ccc1be 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -578,62 +578,9 @@ int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *nilfs,
 static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
                                       unsigned int cmd, void __user *argp)
 {
-        int ret;
-
         if (!capable(CAP_SYS_ADMIN))
                 return -EPERM;
-
-        ret = nilfs_clean_segments(inode->i_sb, argp);
-        clear_nilfs_cond_nongc_write(NILFS_SB(inode->i_sb)->s_nilfs);
-        return ret;
-}
-
-static int nilfs_ioctl_test_cond(struct the_nilfs *nilfs, int cond)
-{
-        return (cond & NILFS_TIMEDWAIT_SEG_WRITE) &&
-                nilfs_cond_nongc_write(nilfs);
-}
-
-static void nilfs_ioctl_clear_cond(struct the_nilfs *nilfs, int cond)
-{
-        if (cond & NILFS_TIMEDWAIT_SEG_WRITE)
-                clear_nilfs_cond_nongc_write(nilfs);
-}
-
-static int nilfs_ioctl_timedwait(struct inode *inode, struct file *filp,
-                                 unsigned int cmd, void __user *argp)
-{
-        struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
-        struct nilfs_wait_cond wc;
-        long ret;
-
-        if (!capable(CAP_SYS_ADMIN))
-                return -EPERM;
-        if (copy_from_user(&wc, argp, sizeof(wc)))
-                return -EFAULT;
-
-        unlock_kernel();
-        ret = wc.wc_flags ?
-                wait_event_interruptible_timeout(
-                        nilfs->ns_cleanerd_wq,
-                        nilfs_ioctl_test_cond(nilfs, wc.wc_cond),
-                        timespec_to_jiffies(&wc.wc_timeout)) :
-                wait_event_interruptible(
-                        nilfs->ns_cleanerd_wq,
-                        nilfs_ioctl_test_cond(nilfs, wc.wc_cond));
-        lock_kernel();
-        nilfs_ioctl_clear_cond(nilfs, wc.wc_cond);
-
-        if (ret > 0) {
-                jiffies_to_timespec(ret, &wc.wc_timeout);
-                if (copy_to_user(argp, &wc, sizeof(wc)))
-                        return -EFAULT;
-                return 0;
-        }
-        if (ret != 0)
-                return -EINTR;
-
-        return wc.wc_flags ? -ETIME : 0;
+        return nilfs_clean_segments(inode->i_sb, argp);
 }
 
 static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
@@ -679,8 +626,6 @@ int nilfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                 return nilfs_ioctl_get_bdescs(inode, filp, cmd, argp);
         case NILFS_IOCTL_CLEAN_SEGMENTS:
                 return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
-        case NILFS_IOCTL_TIMEDWAIT:
-                return nilfs_ioctl_timedwait(inode, filp, cmd, argp);
         case NILFS_IOCTL_SYNC:
                 return nilfs_ioctl_sync(inode, filp, cmd, argp);
         default:
@@ -871,41 +816,6 @@ nilfs_compat_ioctl_clean_segments(struct inode *inode, struct file *filp,
                 inode, filp, cmd, (unsigned long)uargv);
 }
 
-static int
-nilfs_compat_ioctl_timedwait(struct inode *inode, struct file *filp,
-                             unsigned int cmd, unsigned long arg)
-{
-        struct nilfs_wait_cond __user *uwcond;
-        struct nilfs_wait_cond32 __user *uwcond32;
-        struct timespec ts;
-        int cond, flags, ret;
-
-        uwcond = compat_alloc_user_space(sizeof(struct nilfs_wait_cond));
-        uwcond32 = compat_ptr(arg);
-        if (get_user(cond, &uwcond32->wc_cond) ||
-            put_user(cond, &uwcond->wc_cond) ||
-            get_user(flags, &uwcond32->wc_flags) ||
-            put_user(flags, &uwcond->wc_flags) ||
-            get_user(ts.tv_sec, &uwcond32->wc_timeout.tv_sec) ||
-            get_user(ts.tv_nsec, &uwcond32->wc_timeout.tv_nsec) ||
-            put_user(ts.tv_sec, &uwcond->wc_timeout.tv_sec) ||
-            put_user(ts.tv_nsec, &uwcond->wc_timeout.tv_nsec))
-                return -EFAULT;
-
-        ret = nilfs_compat_locked_ioctl(inode, filp, cmd,
-                                        (unsigned long)uwcond);
-        if (ret < 0)
-                return ret;
-
-        if (get_user(ts.tv_sec, &uwcond->wc_timeout.tv_sec) ||
-            get_user(ts.tv_nsec, &uwcond->wc_timeout.tv_nsec) ||
-            put_user(ts.tv_sec, &uwcond32->wc_timeout.tv_sec) ||
-            put_user(ts.tv_nsec, &uwcond32->wc_timeout.tv_nsec))
-                return -EFAULT;
-
-        return 0;
-}
-
 static int nilfs_compat_ioctl_sync(struct inode *inode, struct file *filp,
                                    unsigned int cmd, unsigned long arg)
 {
@@ -943,9 +853,6 @@ long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
         case NILFS_IOCTL32_CLEAN_SEGMENTS:
                 return nilfs_compat_ioctl_clean_segments(
                         inode, filp, NILFS_IOCTL_CLEAN_SEGMENTS, arg);
-        case NILFS_IOCTL32_TIMEDWAIT:
-                return nilfs_compat_ioctl_timedwait(
-                        inode, filp, NILFS_IOCTL_TIMEDWAIT, arg);
         case NILFS_IOCTL_SYNC:
                 return nilfs_compat_ioctl_sync(inode, filp, cmd, arg);
         default:
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 6d66c5cb7b51..5db12d774a03 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2114,11 +2114,8 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
                 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
                 if (update_sr)
                         nilfs_commit_gcdat_inode(nilfs);
-        } else {
+        } else
                 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
-                set_nilfs_cond_nongc_write(nilfs);
-                wake_up(&nilfs->ns_cleanerd_wq);
-        }
 
         sci->sc_nblk_inc += sci->sc_nblk_this_inc;
 
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 852e0bf3a3c5..69b625586226 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -73,7 +73,6 @@ struct the_nilfs *alloc_nilfs(struct block_device *bdev)
         nilfs->ns_gc_inodes_h = NULL;
         INIT_LIST_HEAD(&nilfs->ns_used_segments);
         init_rwsem(&nilfs->ns_segctor_sem);
-        init_waitqueue_head(&nilfs->ns_cleanerd_wq);
 
         return nilfs;
 }
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index 9cd3c113f052..75da37306964 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -37,7 +37,6 @@ enum {
         THE_NILFS_LOADED,       /* Roll-back/roll-forward has done and
                                    the latest checkpoint was loaded */
         THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */
-        THE_NILFS_COND_NONGC_WRITE,     /* Condition to wake up cleanerd */
 };
 
 /**
@@ -74,7 +73,6 @@ enum {
  * @ns_gc_dat: shadow inode of the DAT file inode for GC
  * @ns_gc_inodes: dummy inodes to keep live blocks
  * @ns_gc_inodes_h: hash list to keep dummy inode holding live blocks
- * @ns_cleanerd_wq: wait queue for cleanerd
  * @ns_blocksize_bits: bit length of block size
  * @ns_nsegments: number of segments in filesystem
  * @ns_blocks_per_segment: number of blocks per segment
@@ -151,9 +149,6 @@ struct the_nilfs {
         struct list_head        ns_gc_inodes;
         struct hlist_head      *ns_gc_inodes_h;
 
-        /* cleanerd */
-        wait_queue_head_t       ns_cleanerd_wq;
-
         /* Disk layout information (static) */
         unsigned int            ns_blocksize_bits;
         unsigned long           ns_nsegments;
@@ -186,7 +181,6 @@ static inline int nilfs_##name(struct the_nilfs *nilfs)			\
 THE_NILFS_FNS(INIT, init)
 THE_NILFS_FNS(LOADED, loaded)
 THE_NILFS_FNS(DISCONTINUED, discontinued)
-THE_NILFS_FNS(COND_NONGC_WRITE, cond_nongc_write)
 
 void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);
 struct the_nilfs *alloc_nilfs(struct block_device *);
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index e38fad2f7c0b..b0a6b39eedbc 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -763,18 +763,6 @@ struct nilfs_bdesc {
         __u32 bd_level;
 };
 
-#define NILFS_TIMEDWAIT_WRITE_LOCKED    0x1
-#define NILFS_TIMEDWAIT_SEG_WRITE       0x2
-
-/**
- * struct nilfs_wait_cond -
- */
-struct nilfs_wait_cond {
-        int wc_cond;
-        int wc_flags;
-        struct timespec wc_timeout;
-};
-
 #define NILFS_IOCTL_IDENT               'n'
 
 #define NILFS_IOCTL_CHANGE_CPMODE  \
@@ -795,8 +783,6 @@ struct nilfs_wait_cond {
         _IOWR(NILFS_IOCTL_IDENT, 0x87, struct nilfs_argv)
 #define NILFS_IOCTL_CLEAN_SEGMENTS  \
         _IOW(NILFS_IOCTL_IDENT, 0x88, struct nilfs_argv[5])
-#define NILFS_IOCTL_TIMEDWAIT  \
-        _IOWR(NILFS_IOCTL_IDENT, 0x89, struct nilfs_wait_cond)
 #define NILFS_IOCTL_SYNC  \
         _IOR(NILFS_IOCTL_IDENT, 0x8A, __u64)
 #define NILFS_IOCTL_RESIZE  \
@@ -827,12 +813,6 @@ struct nilfs_sustat32 {
         compat_time_t ss_nongc_ctime;
 };
 
-struct nilfs_wait_cond32 {
-        compat_int_t wc_cond;
-        compat_int_t wc_flags;
-        struct compat_timespec wc_timeout;
-};
-
 #define NILFS_IOCTL32_CHANGE_CPMODE  \
         _IOW(NILFS_IOCTL_IDENT, 0x80, struct nilfs_cpmode32)
 #define NILFS_IOCTL32_GET_CPINFO  \
@@ -847,8 +827,6 @@ struct nilfs_wait_cond32 {
         _IOWR(NILFS_IOCTL_IDENT, 0x87, struct nilfs_argv32)
 #define NILFS_IOCTL32_CLEAN_SEGMENTS  \
         _IOW(NILFS_IOCTL_IDENT, 0x88, struct nilfs_argv32[5])
-#define NILFS_IOCTL32_TIMEDWAIT  \
-        _IOWR(NILFS_IOCTL_IDENT, 0x89, struct nilfs_wait_cond32)
 #endif  /* CONFIG_COMPAT */
 
 #endif  /* _LINUX_NILFS_FS_H */