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Message-id: <002a01d007ae$2f6b9cf0$8e42d6d0$@samsung.com> Date: Mon, 24 Nov 2014 15:16:29 +0900 From: Namjae Jeon <namjae.jeon@...sung.com> To: Dave Chinner <david@...morbit.com>, Theodore Ts'o <tytso@....edu> Cc: linux-fsdevel@...r.kernel.org, linux-ext4 <linux-ext4@...r.kernel.org>, xfs@....sgi.com, linux-kernel@...r.kernel.org, Ashish Sangwan <a.sangwan@...sung.com> Subject: [PATCH v6 1/10] fs: Add support FALLOC_FL_INSERT_RANGE for fallocate 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 create space for writing new data within a file after shifting extents to right as given length. and this command also has same limitation as FALLOC_FL_COLLAPSE_RANGE, that is block boundary and use ftruncate(2) for crosses EOF. Signed-off-by: Namjae Jeon <namjae.jeon@...sung.com> Signed-off-by: Ashish Sangwan <a.sangwan@...sung.com> --- fs/open.c | 8 +++++++- include/uapi/linux/falloc.h | 15 +++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/fs/open.c b/fs/open.c index 36662d0..74ed498 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; diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h index d1197ae..1f20723 100644 --- a/include/uapi/linux/falloc.h +++ b/include/uapi/linux/falloc.h @@ -41,4 +41,19 @@ */ #define FALLOC_FL_ZERO_RANGE 0x10 +/* + * FALLOC_FL_INSERT_RANGE is use to insert 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 a hole. 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 insert space 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 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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