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From: Andiry Xu <jix024@eng.ucsd.edu>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-nvdimm@lists.01.org
Cc: dan.j.williams@intel.com, andy.rudoff@intel.com,
	coughlan@redhat.com, swanson@cs.ucsd.edu, david@fromorbit.com,
	jack@suse.com, swhiteho@redhat.com, miklos@szeredi.hu,
	andiry.xu@gmail.com, Andiry Xu <jix024@cs.ucsd.edu>
Subject: [RFC v2 63/83] File operation: llseek.
Date: Sat, 10 Mar 2018 10:18:44 -0800
Message-ID: <1520705944-6723-64-git-send-email-jix024@eng.ucsd.edu> (raw)
In-Reply-To: <1520705944-6723-1-git-send-email-jix024@eng.ucsd.edu>

From: Andiry Xu <jix024@cs.ucsd.edu>

Search the file radix tree to find hold or data.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
 fs/nova/file.c  |  47 +++++++++++++++++++++++
 fs/nova/inode.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/nova/inode.h |   1 +
 fs/nova/nova.h  |   1 +
 4 files changed, 162 insertions(+)

diff --git a/fs/nova/file.c b/fs/nova/file.c
index b46d4bd..ecaf20a 100644
--- a/fs/nova/file.c
+++ b/fs/nova/file.c
@@ -23,6 +23,53 @@
 #include "nova.h"
 #include "inode.h"
 
+static loff_t nova_llseek(struct file *file, loff_t offset, int origin)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct nova_inode_info *si = NOVA_I(inode);
+	struct nova_inode_info_header *sih = &si->header;
+	int retval;
+
+	if (origin != SEEK_DATA && origin != SEEK_HOLE)
+		return generic_file_llseek(file, offset, origin);
+
+	sih_lock_shared(sih);
+	switch (origin) {
+	case SEEK_DATA:
+		retval = nova_find_region(inode, &offset, 0);
+		if (retval) {
+			sih_unlock_shared(sih);
+			return retval;
+		}
+		break;
+	case SEEK_HOLE:
+		retval = nova_find_region(inode, &offset, 1);
+		if (retval) {
+			sih_unlock_shared(sih);
+			return retval;
+		}
+		break;
+	}
+
+	if ((offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) ||
+	    offset > inode->i_sb->s_maxbytes) {
+		sih_unlock_shared(sih);
+		return -ENXIO;
+	}
+
+	if (offset != file->f_pos) {
+		file->f_pos = offset;
+		file->f_version = 0;
+	}
+
+	sih_unlock_shared(sih);
+	return offset;
+}
+
+
+const struct file_operations nova_dax_file_operations = {
+	.llseek		= nova_llseek,
+};
 
 const struct inode_operations nova_file_inode_operations = {
 	.setattr	= nova_notify_change,
diff --git a/fs/nova/inode.c b/fs/nova/inode.c
index 6fcc5e7..a6d74cb 100644
--- a/fs/nova/inode.c
+++ b/fs/nova/inode.c
@@ -193,6 +193,52 @@ static void nova_truncate_file_blocks(struct inode *inode, loff_t start,
 
 }
 
+/* search the radix tree to find hole or data
+ * in the specified range
+ * Input:
+ * first_blocknr: first block in the specified range
+ * last_blocknr: last_blocknr in the specified range
+ * @data_found: indicates whether data blocks were found
+ * @hole_found: indicates whether a hole was found
+ * hole: whether we are looking for a hole or data
+ */
+static int nova_lookup_hole_in_range(struct super_block *sb,
+	struct nova_inode_info_header *sih,
+	unsigned long first_blocknr, unsigned long last_blocknr,
+	int *data_found, int *hole_found, int hole)
+{
+	struct nova_file_write_entry *entry;
+	unsigned long blocks = 0;
+	unsigned long pgoff, old_pgoff;
+
+	pgoff = first_blocknr;
+	while (pgoff <= last_blocknr) {
+		old_pgoff = pgoff;
+		entry = radix_tree_lookup(&sih->tree, pgoff);
+		if (entry) {
+			*data_found = 1;
+			if (!hole)
+				goto done;
+			pgoff++;
+		} else {
+			*hole_found = 1;
+			entry = nova_find_next_entry(sb, sih, pgoff);
+			pgoff++;
+			if (entry) {
+				pgoff = pgoff > entry->pgoff ?
+					pgoff : entry->pgoff;
+				if (pgoff > last_blocknr)
+					pgoff = last_blocknr + 1;
+			}
+		}
+
+		if (!*hole_found || !hole)
+			blocks += pgoff - old_pgoff;
+	}
+done:
+	return blocks;
+}
+
 /* copy persistent state to struct inode */
 static int nova_read_inode(struct super_block *sb, struct inode *inode,
 	u64 pi_addr)
@@ -232,6 +278,7 @@ static int nova_read_inode(struct super_block *sb, struct inode *inode,
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFREG:
 		inode->i_op = &nova_file_inode_operations;
+		inode->i_fop = &nova_dax_file_operations;
 		break;
 	case S_IFDIR:
 		inode->i_op = &nova_dir_inode_operations;
@@ -929,6 +976,7 @@ struct inode *nova_new_vfs_inode(enum nova_new_inode_type type,
 	case TYPE_CREATE:
 		inode->i_op = &nova_file_inode_operations;
 		inode->i_mapping->a_ops = &nova_aops_dax;
+		inode->i_fop = &nova_dax_file_operations;
 		break;
 	case TYPE_MKNOD:
 		init_special_inode(inode, mode, rdev);
@@ -1170,6 +1218,71 @@ int nova_notify_change(struct dentry *dentry, struct iattr *attr)
 	return ret;
 }
 
+/*
+ * find the file offset for SEEK_DATA/SEEK_HOLE
+ */
+unsigned long nova_find_region(struct inode *inode, loff_t *offset, int hole)
+{
+	struct nova_inode_info *si = NOVA_I(inode);
+	struct nova_inode_info_header *sih = &si->header;
+	unsigned int data_bits = blk_type_to_shift[sih->i_blk_type];
+	unsigned long first_blocknr, last_blocknr;
+	unsigned long blocks = 0, offset_in_block;
+	int data_found = 0, hole_found = 0;
+
+	if (*offset >= inode->i_size)
+		return -ENXIO;
+
+	if (!inode->i_blocks || !sih->i_size) {
+		if (hole)
+			return inode->i_size;
+		else
+			return -ENXIO;
+	}
+
+	offset_in_block = *offset & ((1UL << data_bits) - 1);
+
+	first_blocknr = *offset >> data_bits;
+	last_blocknr = inode->i_size >> data_bits;
+
+	nova_dbgv("find_region offset %llx, first_blocknr %lx, last_blocknr %lx hole %d\n",
+		  *offset, first_blocknr, last_blocknr, hole);
+
+	blocks = nova_lookup_hole_in_range(inode->i_sb, sih,
+		first_blocknr, last_blocknr, &data_found, &hole_found, hole);
+
+	/* Searching data but only hole found till the end */
+	if (!hole && !data_found && hole_found)
+		return -ENXIO;
+
+	if (data_found && !hole_found) {
+		/* Searching data but we are already into them */
+		if (hole)
+			/* Searching hole but only data found, go to the end */
+			*offset = inode->i_size;
+		return 0;
+	}
+
+	/* Searching for hole, hole found and starting inside an hole */
+	if (hole && hole_found && !blocks) {
+		/* we found data after it */
+		if (!data_found)
+			/* last hole */
+			*offset = inode->i_size;
+		return 0;
+	}
+
+	if (offset_in_block) {
+		blocks--;
+		*offset += (blocks << data_bits) +
+			   ((1 << data_bits) - offset_in_block);
+	} else {
+		*offset += blocks << data_bits;
+	}
+
+	return 0;
+}
+
 static ssize_t nova_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	/* DAX does not support direct IO */
diff --git a/fs/nova/inode.h b/fs/nova/inode.h
index 48403cf..693aa90 100644
--- a/fs/nova/inode.h
+++ b/fs/nova/inode.h
@@ -264,6 +264,7 @@ 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);
+unsigned long nova_find_region(struct inode *inode, loff_t *offset, int hole);
 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/nova.h b/fs/nova/nova.h
index 601e082..b2831f6 100644
--- a/fs/nova/nova.h
+++ b/fs/nova/nova.h
@@ -485,6 +485,7 @@ int nova_remove_dentry(struct dentry *dentry, int dec_link,
 	struct nova_inode_update *update, u64 epoch_id);
 
 /* file.c */
+extern const struct file_operations nova_dax_file_operations;
 extern const struct inode_operations nova_file_inode_operations;
 
 /* namei.c */
-- 
2.7.4

  parent reply index

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-10 18:17 [RFC v2 00/83] NOVA: a new file system for persistent memory Andiry Xu
2018-03-10 18:17 ` [RFC v2 01/83] Introduction and documentation of NOVA filesystem Andiry Xu
2018-03-19 20:43   ` Randy Dunlap
2018-03-19 23:00     ` Andiry Xu
2018-04-22  8:05   ` Pavel Machek
2018-03-10 18:17 ` [RFC v2 02/83] Add nova_def.h Andiry Xu
2018-03-10 18:17 ` [RFC v2 03/83] Add super.h Andiry Xu
2018-03-15  4:54   ` Darrick J. Wong
2018-03-15  6:11     ` Andiry Xu
2018-03-15  9:05       ` Arnd Bergmann
2018-03-15 17:51         ` Andiry Xu
2018-03-15 20:04           ` Andreas Dilger
2018-03-15 20:38           ` Arnd Bergmann
2018-03-16  2:59             ` Theodore Y. Ts'o
2018-03-16  6:17               ` Andiry Xu
2018-03-16  6:30                 ` Darrick J. Wong
2018-03-16  9:19               ` Arnd Bergmann
2018-03-10 18:17 ` [RFC v2 04/83] NOVA inode definition Andiry Xu
2018-03-15  5:06   ` Darrick J. Wong
2018-03-15  6:16     ` Andiry Xu
2018-03-10 18:17 ` [RFC v2 05/83] Add NOVA filesystem definitions and useful helper routines Andiry Xu
2018-03-11 12:00   ` Nikolay Borisov
2018-03-11 19:22     ` Eric Biggers
2018-03-11 21:45       ` Andiry Xu
2018-03-19 19:39       ` Andiry Xu
2018-03-19 20:30         ` Eric Biggers
2018-03-19 21:59           ` Andiry Xu
2018-03-10 18:17 ` [RFC v2 06/83] Add inode get/read methods Andiry Xu
2018-04-23  6:12   ` Darrick J. Wong
2018-04-23 15:55     ` Andiry Xu
2018-03-10 18:17 ` [RFC v2 07/83] Initialize inode_info and rebuild inode information in nova_iget() Andiry Xu
2018-03-10 18:17 ` [RFC v2 08/83] NOVA superblock operations Andiry Xu
2018-03-10 18:17 ` [RFC v2 09/83] Add Kconfig and Makefile Andiry Xu
2018-03-11 12:15   ` Nikolay Borisov
2018-03-11 21:32     ` Andiry Xu
2018-03-10 18:17 ` [RFC v2 10/83] Add superblock integrity check Andiry Xu
2018-03-10 18:17 ` [RFC v2 11/83] Add timing and I/O statistics for performance analysis and profiling Andiry Xu
2018-03-10 18:17 ` [RFC v2 12/83] Add timing for mount and init Andiry Xu
2018-03-10 18:17 ` [RFC v2 13/83] Add remount_fs and show_options methods Andiry Xu
2018-03-10 18:17 ` [RFC v2 14/83] Add range node kmem cache Andiry Xu
2018-03-11 11:55   ` Nikolay Borisov
2018-03-11 21:31     ` Andiry Xu
2018-03-10 18:17 ` [RFC v2 15/83] Add free list data structure Andiry Xu
2018-03-10 18:17 ` [RFC v2 16/83] Initialize block map and free lists in nova_init() Andiry Xu
2018-03-11 12:12   ` Nikolay Borisov
2018-03-11 21:30     ` Andiry Xu
2018-03-10 18:17 ` [RFC v2 17/83] Add statfs support Andiry Xu
2018-03-10 18:17 ` [RFC v2 18/83] Add freelist statistics printing Andiry Xu
2018-03-10 18:18 ` [RFC v2 19/83] Add pmem block free routines Andiry Xu
2018-03-10 18:18 ` [RFC v2 20/83] Pmem block allocation routines Andiry Xu
2018-03-10 18:18 ` [RFC v2 21/83] Add log structure Andiry Xu
2018-03-10 18:18 ` [RFC v2 22/83] Inode log pages allocation and reclaimation Andiry Xu
2018-03-10 18:18 ` [RFC v2 23/83] Save allocator to pmem in put_super Andiry Xu
2018-03-10 18:18 ` [RFC v2 24/83] Initialize and allocate inode table Andiry Xu
2018-03-10 18:18 ` [RFC v2 25/83] Support get normal inode address and inode table extentsion Andiry Xu
2018-03-10 18:18 ` [RFC v2 26/83] Add inode_map to track inuse inodes Andiry Xu
2018-03-10 18:18 ` [RFC v2 27/83] Save the inode inuse list to pmem upon umount Andiry Xu
2018-03-10 18:18 ` [RFC v2 28/83] Add NOVA address space operations Andiry Xu
2018-03-10 18:18 ` [RFC v2 29/83] Add write_inode and dirty_inode routines Andiry Xu
2018-03-10 18:18 ` [RFC v2 30/83] New NOVA inode allocation Andiry Xu
2018-03-10 18:18 ` [RFC v2 31/83] Add new vfs " Andiry Xu
2018-03-10 18:18 ` [RFC v2 32/83] Add log entry definitions Andiry Xu
2018-03-10 18:18 ` [RFC v2 33/83] Inode log and entry printing for debug purpose Andiry Xu
2018-03-10 18:18 ` [RFC v2 34/83] Journal: NOVA light weight journal definitions Andiry Xu
2018-03-10 18:18 ` [RFC v2 35/83] Journal: Lite journal helper routines Andiry Xu
2018-03-10 18:18 ` [RFC v2 36/83] Journal: Lite journal recovery Andiry Xu
2018-03-10 18:18 ` [RFC v2 37/83] Journal: Lite journal create and commit Andiry Xu
2018-03-10 18:18 ` [RFC v2 38/83] Journal: NOVA lite journal initialization Andiry Xu
2018-03-10 18:18 ` [RFC v2 39/83] Log operation: dentry append Andiry Xu
2018-03-10 18:18 ` [RFC v2 40/83] Log operation: file write entry append Andiry Xu
2018-03-10 18:18 ` [RFC v2 41/83] Log operation: setattr " Andiry Xu
2018-03-10 18:18 ` [RFC v2 42/83] Log operation: link change append Andiry Xu
2018-03-10 18:18 ` [RFC v2 43/83] Log operation: in-place update log entry Andiry Xu
2018-03-10 18:18 ` [RFC v2 44/83] Log operation: invalidate log entries Andiry Xu
2018-03-10 18:18 ` [RFC v2 45/83] Log operation: file inode log lookup and assign Andiry Xu
2018-03-10 18:18 ` [RFC v2 46/83] Dir: Add Directory radix tree insert/remove methods Andiry Xu
2018-03-10 18:18 ` [RFC v2 47/83] Dir: Add initial dentries when initializing a directory inode log Andiry Xu
2018-03-10 18:18 ` [RFC v2 48/83] Dir: Readdir operation Andiry Xu
2018-03-10 18:18 ` [RFC v2 49/83] Dir: Append create/remove dentry Andiry Xu
2018-03-10 18:18 ` [RFC v2 50/83] Inode: Add nova_evict_inode Andiry Xu
2018-03-10 18:18 ` [RFC v2 51/83] Rebuild: directory inode Andiry Xu
2018-03-10 18:18 ` [RFC v2 52/83] Rebuild: file inode Andiry Xu
2018-03-10 18:18 ` [RFC v2 53/83] Namei: lookup Andiry Xu
2018-03-10 18:18 ` [RFC v2 54/83] Namei: create and mknod Andiry Xu
2018-03-10 18:18 ` [RFC v2 55/83] Namei: mkdir Andiry Xu
2018-03-10 18:18 ` [RFC v2 56/83] Namei: link and unlink Andiry Xu
2018-03-10 18:18 ` [RFC v2 57/83] Namei: rmdir Andiry Xu
2018-03-10 18:18 ` [RFC v2 58/83] Namei: rename Andiry Xu
2018-03-10 18:18 ` [RFC v2 59/83] Namei: setattr Andiry Xu
2018-03-10 18:18 ` [RFC v2 60/83] Add special inode operations Andiry Xu
2018-03-10 18:18 ` [RFC v2 61/83] Super: Add nova_export_ops Andiry Xu
2018-03-10 18:18 ` [RFC v2 62/83] File: getattr and file inode operations Andiry Xu
2018-03-10 18:18 ` Andiry Xu [this message]
2018-03-10 18:18 ` [RFC v2 64/83] File operation: open, fsync, flush Andiry Xu
2018-03-10 18:18 ` [RFC v2 65/83] File operation: read Andiry Xu
2018-03-10 18:18 ` [RFC v2 66/83] Super: Add file write item cache Andiry Xu
2018-03-10 18:18 ` [RFC v2 67/83] Dax: commit list of file write items to log Andiry Xu
2018-03-10 18:18 ` [RFC v2 68/83] File operation: copy-on-write write Andiry Xu
2018-03-10 18:18 ` [RFC v2 69/83] Super: Add module param inplace_data_updates Andiry Xu
2018-03-10 18:18 ` [RFC v2 70/83] File operation: Inplace write Andiry Xu
2018-03-10 18:18 ` [RFC v2 71/83] Symlink support Andiry Xu
2018-03-10 18:18 ` [RFC v2 72/83] File operation: fallocate Andiry Xu
2018-03-10 18:18 ` [RFC v2 73/83] Dax: Add iomap operations Andiry Xu
2018-03-10 18:18 ` [RFC v2 74/83] File operation: Mmap Andiry Xu
2018-03-10 18:18 ` [RFC v2 75/83] File operation: read/write iter Andiry Xu
2018-03-10 18:18 ` [RFC v2 76/83] Ioctl support Andiry Xu
2018-03-10 18:18 ` [RFC v2 77/83] GC: Fast garbage collection Andiry Xu
2018-03-10 18:18 ` [RFC v2 78/83] GC: Thorough " Andiry Xu
2018-03-10 18:19 ` [RFC v2 79/83] Normal recovery Andiry Xu
2018-03-10 18:19 ` [RFC v2 80/83] Failure recovery: bitmap operations Andiry Xu
2018-03-10 18:19 ` [RFC v2 81/83] Failure recovery: Inode pages recovery routines Andiry Xu
2018-03-10 18:19 ` [RFC v2 82/83] Failure recovery: Per-CPU recovery Andiry Xu
2018-03-10 18:19 ` [RFC v2 83/83] Sysfs support Andiry Xu
2018-03-15  0:33   ` Randy Dunlap
2018-03-15  6:07     ` Andiry Xu
2018-03-22 15:00   ` David Sterba
2018-03-23  0:31     ` Andiry Xu
2018-03-11  2:14 ` [RFC v2 00/83] NOVA: a new file system for persistent memory Theodore Y. Ts'o
2018-03-11  4:58   ` Andiry Xu

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