[09/10] ext4: factor out the common checking part of all fallocate operations

Commit Message

Zhang Yi Aug. 30, 2024, 7:37 a.m. UTC

From: Zhang Yi <[e-mail]>

Now the beginning of all the five functions in ext4_fallocate() (punch
hole, zero range, insert range, collapse range and normal fallocate) are
almost the same, they need to hold i_rwsem and check the validity of
input parameters, so move the holding of i_rwsem to ext4_fallocate()
and factor out a common helper to check the input parameters can make
the code more clear.

Signed-off-by: Zhang Yi <[e-mail]>
---
 fs/ext4/extents.c | 132 ++++++++++++++++++----------------------------
 fs/ext4/inode.c   |  13 ++---
 2 files changed, 56 insertions(+), 89 deletions(-)

Patch

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 4e23f9e8a7be..d4c10b4b4972 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4548,23 +4548,14 @@  static long ext4_zero_range(struct file *file, loff_t offset,
 	int ret, flags, credits;
 
 	trace_ext4_zero_range(inode, offset, len, mode);
-
-	inode_lock(inode);
-
-	/*
-	 * Indirect files do not support unwritten extents
-	 */
-	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
 	    (end > inode->i_size || end > EXT4_I(inode)->i_disksize)) {
 		new_size = end;
 		ret = inode_newsize_ok(inode, new_size);
 		if (ret)
-			goto out;
+			return ret;
 	}
 
 	/* Wait all existing dio workers, newcomers will block on i_rwsem */
@@ -4572,7 +4563,7 @@  static long ext4_zero_range(struct file *file, loff_t offset,
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released
@@ -4657,8 +4648,6 @@  static long ext4_zero_range(struct file *file, loff_t offset,
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }
 
@@ -4672,14 +4661,7 @@  static long ext4_do_fallocate(struct file *file, loff_t offset,
 	int ret;
 
 	trace_ext4_fallocate_enter(inode, offset, len, mode);
-
-	inode_lock(inode);
-
-	/* We only support preallocation for extent-based files only. */
-	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
 	    (end > inode->i_size || end > EXT4_I(inode)->i_disksize)) {
@@ -4709,11 +4691,46 @@  static long ext4_do_fallocate(struct file *file, loff_t offset,
 					EXT4_I(inode)->i_sync_tid);
 	}
 out:
-	inode_unlock(inode);
 	trace_ext4_fallocate_exit(inode, offset, len_lblk, ret);
 	return ret;
 }
 
+static int ext4_fallocate_check(struct inode *inode, int mode,
+				loff_t offset, loff_t len)
+{
+	/* Currently except punch_hole, just for extent based files. */
+	if (!(mode & FALLOC_FL_PUNCH_HOLE) &&
+	    !ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		return -EOPNOTSUPP;
+
+	/*
+	 * Insert range and collapse range works only on fs cluster size
+	 * aligned regions.
+	 */
+	if (mode & (FALLOC_FL_INSERT_RANGE | FALLOC_FL_COLLAPSE_RANGE) &&
+	    !IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(inode->i_sb)))
+		return -EINVAL;
+
+	if (mode & FALLOC_FL_INSERT_RANGE) {
+		/* Collapse range, offset must be less than i_size */
+		if (offset >= inode->i_size)
+			return -EINVAL;
+		/* Check whether the maximum file size would be exceeded */
+		if (len > inode->i_sb->s_maxbytes - inode->i_size)
+			return -EFBIG;
+	} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
+		/*
+		 * Insert range, there is no need to overlap collapse
+		 * range with EOF, in which case it is effectively a
+		 * truncate operation.
+		 */
+		if (offset + len >= inode->i_size)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
 /*
  * preallocate space for a file. This implements ext4's fallocate file
  * operation, which gets called from sys_fallocate system call.
@@ -4744,9 +4761,12 @@  long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 
 	inode_lock(inode);
 	ret = ext4_convert_inline_data(inode);
-	inode_unlock(inode);
 	if (ret)
-		return ret;
+		goto out;
+
+	ret = ext4_fallocate_check(inode, mode, offset, len);
+	if (ret)
+		goto out;
 
 	if (mode & FALLOC_FL_PUNCH_HOLE)
 		ret = ext4_punch_hole(file, offset, len);
@@ -4758,7 +4778,8 @@  long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 		ret = ext4_zero_range(file, offset, len, mode);
 	else
 		ret = ext4_do_fallocate(file, offset, len, mode);
-
+out:
+	inode_unlock(inode);
 	return ret;
 }
 
@@ -5267,36 +5288,14 @@  static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
 	int ret;
 
 	trace_ext4_collapse_range(inode, offset, len);
-
-	inode_lock(inode);
-
-	/* Currently just for extent based files */
-	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
-
-	/* Collapse range works only on fs cluster size aligned regions. */
-	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	/*
-	 * There is no need to overlap collapse range with EOF, in which case
-	 * it is effectively a truncate operation
-	 */
-	if (offset + len >= inode->i_size) {
-		ret = -EINVAL;
-		goto out;
-	}
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	/* Wait for existing dio to complete */
 	inode_dio_wait(inode);
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released from
@@ -5365,8 +5364,6 @@  static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }
 
@@ -5392,39 +5389,14 @@  static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
 	loff_t start;
 
 	trace_ext4_insert_range(inode, offset, len);
-
-	inode_lock(inode);
-
-	/* Currently just for extent based files */
-	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
-
-	/* Insert range works only on fs cluster size aligned regions. */
-	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	/* Offset must be less than i_size */
-	if (offset >= inode->i_size) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	/* Check whether the maximum file size would be exceeded */
-	if (len > inode->i_sb->s_maxbytes - inode->i_size) {
-		ret = -EFBIG;
-		goto out;
-	}
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	/* Wait for existing dio to complete */
 	inode_dio_wait(inode);
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released from
@@ -5525,8 +5497,6 @@  static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index dfaf9e9d6ad8..57636c656fa5 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3923,15 +3923,14 @@  int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	unsigned long blocksize = i_blocksize(inode);
 	handle_t *handle;
 	unsigned int credits;
-	int ret = 0;
+	int ret;
 
 	trace_ext4_punch_hole(inode, offset, length, 0);
-
-	inode_lock(inode);
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	/* No need to punch hole beyond i_size */
 	if (offset >= inode->i_size)
-		goto out;
+		return 0;
 
 	/*
 	 * If the hole extends beyond i_size, set the hole to end after
@@ -3951,7 +3950,7 @@  int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	if (offset & (blocksize - 1) || end & (blocksize - 1)) {
 		ret = ext4_inode_attach_jinode(inode);
 		if (ret < 0)
-			goto out;
+			return ret;
 	}
 
 	/* Wait all existing dio workers, newcomers will block on i_rwsem */
@@ -3959,7 +3958,7 @@  int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released from
@@ -4036,8 +4035,6 @@  int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }