xfs
[Top] [All Lists]

[PATCH 1/3] fs: Add FALLOC_FL_INSERT_RANGE flags for fallocate

To: viro@xxxxxxxxxxxxxxxxxx, david@xxxxxxxxxxxxx, hch@xxxxxxxxxxxxx, tytso@xxxxxxx, adilger.kernel@xxxxxxxxx, jack@xxxxxxx, lczerner@xxxxxxxxxx
Subject: [PATCH 1/3] fs: Add FALLOC_FL_INSERT_RANGE flags for fallocate
From: Namjae Jeon <linkinjeon@xxxxxxxxx>
Date: Mon, 31 Mar 2014 23:54:13 +0900
Cc: linux-fsdevel@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx, linux-ext4@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, Namjae Jeon <linkinjeon@xxxxxxxxx>, Namjae Jeon <namjae.jeon@xxxxxxxxxxx>, Ashish Sangwan <a.sangwan@xxxxxxxxxxx>
Delivered-to: xfs@xxxxxxxxxxx
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=15phU208XB1cWUPNKXcnqEngwrQ4d0KA9nhpSV7pejs=; b=G7u8nJAdpUexgwEP6ep2AivI4zil53GBOygnNGKmKmjjpKEWFs0Fqg6/DyCyNV+NJ1 WiAWrI9wFlVJbIFAtZ2Imu5arKnCXgiSrYtq8ejXewKRsvFLodkV6Wxtj7cadeNYu7wD xI0lzMZlWaR6AwdH2I/7EHWTOp4cJGJukNP9ZJ+vHZEniQDjDu4ds7vYPSWtkXDAbi5x IHNiQkuhZ9PJH50Th3iejeQW+9iKYbZ0UkUaupWMMsB5+BtU7RtVjaeRpMPWjQbgPijg J5T5k2WrX2zeRxlSo4/YplHC1L/Vs4WEEIEik2IzrSPRDSWaN8r537np3uubBQPY+aqB bjww==
From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>

FALLOC_FL_INSERT_RANGE command is the opposite command of
FALLOC_FL_COLLAPSE_RANGE that is needed for advertisers or someone who want to
add some data in the middle of file. FALLOC_FL_INSERT_RANGE will insert a range
of a file after shifting extents to right as given length.
and this command also has same limitation as FALLOC_FL_COLLAPSE_RANGE,
block boundary and use ftruncate(2) for crosses EOF.

Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
Signed-off-by: Ashish Sangwan <a.sangwan@xxxxxxxxxxx>
---
 fs/open.c                   | 21 ++++++++++++++++++---
 include/uapi/linux/falloc.h | 17 +++++++++++++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index 631aea8..34727ba 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -232,7 +232,8 @@ int do_fallocate(struct file *file, int mode, loff_t 
offset, loff_t len)
 
        /* Return error if mode is not supported */
        if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
-                    FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
+                    FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
+                    FALLOC_FL_INSERT_RANGE))
                return -EOPNOTSUPP;
 
        /* Punch hole and zero range are mutually exclusive */
@@ -250,6 +251,11 @@ int do_fallocate(struct file *file, int mode, loff_t 
offset, loff_t len)
            (mode & ~FALLOC_FL_COLLAPSE_RANGE))
                return -EINVAL;
 
+       /* Insert range should only be used exclusively. */
+       if ((mode & FALLOC_FL_INSERT_RANGE) &&
+           (mode & ~FALLOC_FL_INSERT_RANGE))
+               return -EINVAL;
+
        if (!(file->f_mode & FMODE_WRITE))
                return -EBADF;
 
@@ -257,8 +263,8 @@ int do_fallocate(struct file *file, int mode, loff_t 
offset, loff_t len)
         * It's not possible to punch hole or perform collapse range
         * on append only file
         */
-       if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE)
-           && IS_APPEND(inode))
+       if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE |
+           FALLOC_FL_INSERT_RANGE) && IS_APPEND(inode))
                return -EPERM;
 
        if (IS_IMMUTABLE(inode))
@@ -286,6 +292,11 @@ int do_fallocate(struct file *file, int mode, loff_t 
offset, loff_t len)
        if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
                return -EFBIG;
 
+       /* Check for wrap through zero in case of insert range. */
+       if ((mode & FALLOC_FL_INSERT_RANGE) && (inode->i_size + len) >
+           inode->i_sb->s_maxbytes)
+               return -EFBIG;
+
        /*
         * There is no need to overlap collapse range with EOF, in which case
         * it is effectively a truncate operation
@@ -294,6 +305,10 @@ int do_fallocate(struct file *file, int mode, loff_t 
offset, loff_t len)
            (offset + len >= i_size_read(inode)))
                return -EINVAL;
 
+       /* Offset should be less than i_size in case of insert range. */
+       if ((mode & FALLOC_FL_INSERT_RANGE) && (offset >= i_size_read(inode)))
+               return -EINVAL;
+
        if (!file->f_op->fallocate)
                return -EOPNOTSUPP;
 
diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h
index d1197ae..f4d12eb 100644
--- a/include/uapi/linux/falloc.h
+++ b/include/uapi/linux/falloc.h
@@ -41,4 +41,21 @@
  */
 #define FALLOC_FL_ZERO_RANGE           0x10
 
+/*
+ * FALLOC_FL_INSERT_RANGE is use to allocate disk space within the file size
+ * without overwriting any existing data. The contents of the file beyond 
offset
+ * are shifted towards right by len bytes to create space for inserting
+ * new disk blocks and in this space new zeroed out disk blocks are inserted.
+ * As such, this operation will increase the size of the file by len bytes.
+ * Different filesystems may implement different limitations on the granularity
+ * of the operation. Most will limit operations to filesystem block size
+ * boundaries, but this boundary may be larger or smaller depending on
+ * the filesystem and/or the configuration of the filesystem or file.
+ *
+ * Attempting to allocate new blocks using this flag at OR beyond the end of
+ * the file is considered an illegal operation - just use ftruncate(2) or
+ * fallocate(2) with mode 0 for such type of operations.
+ */
+#define FALLOC_FL_INSERT_RANGE         0x20
+
 #endif /* _UAPI_FALLOC_H_ */
-- 
1.7.11-rc0

<Prev in Thread] Current Thread [Next in Thread>
  • [PATCH 1/3] fs: Add FALLOC_FL_INSERT_RANGE flags for fallocate, Namjae Jeon <=