Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/ryusuke/nilfs2

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: add reader's lock for cno in nilfs_ioctl_sync
  nilfs2: delete unnecessary condition in load_segment_summary
  nilfs2: move iterator to write log into segment buffer
  nilfs2: get rid of s_dirt flag use
  nilfs2: get rid of nilfs_segctor_req struct
  nilfs2: delete unnecessary condition in nilfs_dat_translate
  nilfs2: fix potential hang in nilfs_error on errors=remount-ro
  nilfs2: use mnt_want_write in ioctls where write access is needed
  nilfs2: issue discard request after cleaning segments

Documentation/filesystems/nilfs2.txt

@@ -74,6 +74,9 @@ norecovery		Disable recovery of the filesystem on mount.
 			This disables every write access on the device for
 			read-only mounts or snapshots.  This option will fail
 			for r/w mounts on an unclean volume.
+discard			Issue discard/TRIM commands to the underlying block
+			device when blocks are freed.  This is useful for SSD
+			devices and sparse/thinly-provisioned LUNs.
 
 NILFS2 usage
 ============

fs/nilfs2/dat.c

@@ -388,8 +388,7 @@ int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
 		ret = -ENOENT;
 		goto out;
 	}
-	if (blocknrp != NULL)
-		*blocknrp = blocknr;
+	*blocknrp = blocknr;
 
  out:
 	kunmap_atomic(kaddr, KM_USER0);

fs/nilfs2/ioctl.c

@@ -26,6 +26,7 @@
 #include <linux/capability.h>	/* capable() */
 #include <linux/uaccess.h>	/* copy_from_user(), copy_to_user() */
 #include <linux/vmalloc.h>
+#include <linux/mount.h>	/* mnt_want_write(), mnt_drop_write() */
 #include <linux/nilfs2_fs.h>
 #include "nilfs.h"
 #include "segment.h"
@@ -107,20 +108,28 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
+
+	ret = mnt_want_write(filp->f_path.mnt);
+	if (ret)
+		return ret;
+
+	ret = -EFAULT;
 	if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
-		return -EFAULT;
+		goto out;
 
 	mutex_lock(&nilfs->ns_mount_mutex);
+
 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
 	ret = nilfs_cpfile_change_cpmode(
 		cpfile, cpmode.cm_cno, cpmode.cm_mode);
-	if (unlikely(ret < 0)) {
+	if (unlikely(ret < 0))
 		nilfs_transaction_abort(inode->i_sb);
-		mutex_unlock(&nilfs->ns_mount_mutex);
-		return ret;
-	}
-	nilfs_transaction_commit(inode->i_sb); /* never fails */
+	else
+		nilfs_transaction_commit(inode->i_sb); /* never fails */
+
 	mutex_unlock(&nilfs->ns_mount_mutex);
+out:
+	mnt_drop_write(filp->f_path.mnt);
 	return ret;
 }
 
@@ -135,16 +144,23 @@ nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
+
+	ret = mnt_want_write(filp->f_path.mnt);
+	if (ret)
+		return ret;
+
+	ret = -EFAULT;
 	if (copy_from_user(&cno, argp, sizeof(cno)))
-		return -EFAULT;
+		goto out;
 
 	nilfs_transaction_begin(inode->i_sb, &ti, 0);
 	ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
-	if (unlikely(ret < 0)) {
+	if (unlikely(ret < 0))
 		nilfs_transaction_abort(inode->i_sb);
-		return ret;
-	}
-	nilfs_transaction_commit(inode->i_sb); /* never fails */
+	else
+		nilfs_transaction_commit(inode->i_sb); /* never fails */
+out:
+	mnt_drop_write(filp->f_path.mnt);
 	return ret;
 }
 
@@ -496,22 +512,30 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	ret = mnt_want_write(filp->f_path.mnt);
+	if (ret)
+		return ret;
+
+	ret = -EFAULT;
 	if (copy_from_user(argv, argp, sizeof(argv)))
-		return -EFAULT;
+		goto out;
 
+	ret = -EINVAL;
 	nsegs = argv[4].v_nmembs;
 	if (argv[4].v_size != argsz[4])
-		return -EINVAL;
+		goto out;
+
 	/*
 	 * argv[4] points to segment numbers this ioctl cleans.  We
 	 * use kmalloc() for its buffer because memory used for the
 	 * segment numbers is enough small.
 	 */
 	kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
 			       nsegs * sizeof(__u64));
-	if (IS_ERR(kbufs[4]))
-		return PTR_ERR(kbufs[4]);
-
+	if (IS_ERR(kbufs[4])) {
+		ret = PTR_ERR(kbufs[4]);
+		goto out;
+	}
 	nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 
 	for (n = 0; n < 4; n++) {
@@ -563,10 +587,12 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
 		nilfs_remove_all_gcinode(nilfs);
 	clear_nilfs_gc_running(nilfs);
 
- out_free:
+out_free:
 	while (--n >= 0)
 		vfree(kbufs[n]);
 	kfree(kbufs[4]);
+out:
+	mnt_drop_write(filp->f_path.mnt);
 	return ret;
 }
 
@@ -575,13 +601,17 @@ static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
 {
 	__u64 cno;
 	int ret;
+	struct the_nilfs *nilfs;
 
 	ret = nilfs_construct_segment(inode->i_sb);
 	if (ret < 0)
 		return ret;
 
 	if (argp != NULL) {
-		cno = NILFS_SB(inode->i_sb)->s_nilfs->ns_cno - 1;
+		nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
+		down_read(&nilfs->ns_segctor_sem);
+		cno = nilfs->ns_cno - 1;
+		up_read(&nilfs->ns_segctor_sem);
 		if (copy_to_user(argp, &cno, sizeof(cno)))
 			return -EFAULT;
 	}

fs/nilfs2/recovery.c

@@ -39,7 +39,6 @@ enum {
 	NILFS_SEG_FAIL_IO,
 	NILFS_SEG_FAIL_MAGIC,
 	NILFS_SEG_FAIL_SEQ,
-	NILFS_SEG_FAIL_CHECKSUM_SEGSUM,
 	NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT,
 	NILFS_SEG_FAIL_CHECKSUM_FULL,
 	NILFS_SEG_FAIL_CONSISTENCY,
@@ -71,10 +70,6 @@ static int nilfs_warn_segment_error(int err)
 		printk(KERN_WARNING
 		       "NILFS warning: Sequence number mismatch\n");
 		break;
-	case NILFS_SEG_FAIL_CHECKSUM_SEGSUM:
-		printk(KERN_WARNING
-		       "NILFS warning: Checksum error in segment summary\n");
-		break;
 	case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT:
 		printk(KERN_WARNING
 		       "NILFS warning: Checksum error in super root\n");
@@ -206,19 +201,15 @@ int nilfs_read_super_root_block(struct super_block *sb, sector_t sr_block,
  * @pseg_start: start disk block number of partial segment
  * @seg_seq: sequence number requested
  * @ssi: pointer to nilfs_segsum_info struct to store information
- * @full_check: full check flag
- *              (0: only checks segment summary CRC, 1: data CRC)
  */
 static int
 load_segment_summary(struct nilfs_sb_info *sbi, sector_t pseg_start,
-		     u64 seg_seq, struct nilfs_segsum_info *ssi,
-		     int full_check)
+		     u64 seg_seq, struct nilfs_segsum_info *ssi)
 {
 	struct buffer_head *bh_sum;
 	struct nilfs_segment_summary *sum;
-	unsigned long offset, nblock;
-	u64 check_bytes;
-	u32 crc, crc_sum;
+	unsigned long nblock;
+	u32 crc;
 	int ret = NILFS_SEG_FAIL_IO;
 
 	bh_sum = sb_bread(sbi->s_super, pseg_start);
@@ -237,34 +228,24 @@ load_segment_summary(struct nilfs_sb_info *sbi, sector_t pseg_start,
 		ret = NILFS_SEG_FAIL_SEQ;
 		goto failed;
 	}
-	if (full_check) {
-		offset = sizeof(sum->ss_datasum);
-		check_bytes =
-			((u64)ssi->nblocks << sbi->s_super->s_blocksize_bits);
-		nblock = ssi->nblocks;
-		crc_sum = le32_to_cpu(sum->ss_datasum);
-		ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
-	} else { /* only checks segment summary */
-		offset = sizeof(sum->ss_datasum) + sizeof(sum->ss_sumsum);
-		check_bytes = ssi->sumbytes;
-		nblock = ssi->nsumblk;
-		crc_sum = le32_to_cpu(sum->ss_sumsum);
-		ret = NILFS_SEG_FAIL_CHECKSUM_SEGSUM;
-	}
 
+	nblock = ssi->nblocks;
 	if (unlikely(nblock == 0 ||
 		     nblock > sbi->s_nilfs->ns_blocks_per_segment)) {
 		/* This limits the number of blocks read in the CRC check */
 		ret = NILFS_SEG_FAIL_CONSISTENCY;
 		goto failed;
 	}
-	if (calc_crc_cont(sbi, bh_sum, &crc, offset, check_bytes,
+	if (calc_crc_cont(sbi, bh_sum, &crc, sizeof(sum->ss_datasum),
+			  ((u64)nblock << sbi->s_super->s_blocksize_bits),
 			  pseg_start, nblock)) {
 		ret = NILFS_SEG_FAIL_IO;
 		goto failed;
 	}
-	if (crc == crc_sum)
+	if (crc == le32_to_cpu(sum->ss_datasum))
 		ret = 0;
+	else
+		ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
  failed:
 	brelse(bh_sum);
  out:
@@ -598,7 +579,7 @@ static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
 
 	while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
 
-		ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
+		ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi);
 		if (ret) {
 			if (ret == NILFS_SEG_FAIL_IO) {
 				err = -EIO;
@@ -821,7 +802,7 @@ int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi,
 
 	for (;;) {
 		/* Load segment summary */
-		ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
+		ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi);
 		if (ret) {
 			if (ret == NILFS_SEG_FAIL_IO)
 				goto failed;

fs/nilfs2/segbuf.c

@@ -40,6 +40,11 @@ struct nilfs_write_info {
 };
 
 
+static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
+			      struct the_nilfs *nilfs);
+static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
+
+
 static struct kmem_cache *nilfs_segbuf_cachep;
 
 static void nilfs_segbuf_init_once(void *obj)
@@ -302,6 +307,19 @@ void nilfs_truncate_logs(struct list_head *logs,
 	}
 }
 
+int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
+{
+	struct nilfs_segment_buffer *segbuf;
+	int ret = 0;
+
+	list_for_each_entry(segbuf, logs, sb_list) {
+		ret = nilfs_segbuf_write(segbuf, nilfs);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
 int nilfs_wait_on_logs(struct list_head *logs)
 {
 	struct nilfs_segment_buffer *segbuf;

fs/nilfs2/segbuf.h

@@ -166,13 +166,10 @@ nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf,
 	segbuf->sb_sum.nfileblk++;
 }
 
-int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
-		       struct the_nilfs *nilfs);
-int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
-
 void nilfs_clear_logs(struct list_head *logs);
 void nilfs_truncate_logs(struct list_head *logs,
 			 struct nilfs_segment_buffer *last);
+int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs);
 int nilfs_wait_on_logs(struct list_head *logs);
 
 static inline void nilfs_destroy_logs(struct list_head *logs)