From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Update FALLOC_FL_INSERT_RANGE flag in fallocate. Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Signed-off-by: Ashish Sangwan <a.sangwan@xxxxxxxxxxx> --- man2/fallocate.2 | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 82 insertions(+), 6 deletions(-) diff --git a/man2/fallocate.2 b/man2/fallocate.2 index adf42db..9b3c460 100644 --- a/man2/fallocate.2 +++ b/man2/fallocate.2 @@ -8,7 +8,7 @@ .\" 2011-09-19: Added FALLOC_FL_PUNCH_HOLE .\" 2011-09-19: Substantial restructuring of the page .\" -.TH FALLOCATE 2 2015-01-22 "Linux" "Linux Programmer's Manual" +.TH FALLOCATE 2 2015-02-14 "Linux" "Linux Programmer's Manual" .SH NAME fallocate \- manipulate file space .SH SYNOPSIS @@ -225,6 +225,56 @@ XFS (since Linux 3.14) .IP * ext4, for extent-based files (since Linux 3.14) .\" commit b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 +.SS Increasing file space +.\" TODO: Mention commit id and supporting Linux version +Specifying the +.BR FALLOC_FL_INSERT_RANGE +flag in +.I mode +will increase the file space by inserting a hole within the file size without +overwriting any existing data. The hole will start at +.I offset +and continue for +.I len +bytes. For inserting hole inside file, the contents of the file starting at +.I offset +will be shifted towards right by +.I len +bytes. Inserting a hole inside the file will increase the file size by +.I len +bytes. + +This mode has the same limitation as +.BR FALLOC_FL_COLLAPSE_RANGE +regarding the +granularity of the operation. +If the granulrity requirements are not met, +.BR fallocate () +will fail with the error +.BR EINVAL. +If the +.I offset +overlaps with end of file OR if it is greater than end of file, an error is +returned. For such type of operations, i.e. inserting a hole at the end of +file, +.BR ftruncate(2) +should be used. +In case +.IR offset + len +exceeds the maximum file size, errno will be set to +.B EFBIG. + +No other flags may be specified in +.IR mode +in conjunction with +.BR FALLOC_FL_INSERT_RANGE . + +As of Linux XXXX, +.\" TODO: Mention commit id and supporting Linux version +.B FALLOC_FL_INSERT_RANGE +is supported by +ext4 (only for extent-based files) and XFS. + .SH RETURN VALUE On success, .BR fallocate () @@ -242,6 +292,12 @@ is not a valid file descriptor, or is not opened for writing. .IR offset + len exceeds the maximum file size. .TP +.B EFBIG +.I mode +is +.BR FALLOC_FL_INSERT_RANGE , +the current file size+len excceds the maximum file size. +.TP .B EINTR A signal was caught during execution. .TP @@ -270,7 +326,17 @@ reaches or passes the end of the file. .B EINVAL .I mode is -.BR FALLOC_FL_COLLAPSE_RANGE , +.BR FALLOC_FL_INSERT_RANGE +and the range specified by +.I offset +reaches or passes the end of the file. +.TP +.B EINVAL +.I mode +is +.BR FALLOC_FL_COLLAPSE_RANGE +or +.BR FALLOC_FL_INSERT_RANGE , but either .I offset or @@ -279,18 +345,24 @@ is not a multiple of the filesystem block size. .TP .B EINVAL .I mode -contains both +contains either of .B FALLOC_FL_COLLAPSE_RANGE +or +.B FALLOC_FL_INSERT_RANGE and other flags; no other flags are permitted with -.BR FALLOC_FL_COLLAPSE_RANGE . +.BR FALLOC_FL_COLLAPSE_RANGE +or +.BR FALLOC_FL_INSERT_RANGE . .TP .B EINVAL .I mode is .BR FALLOC_FL_COLLAPSE_RANGE or -.BR FALLOC_FL_ZERO_RANGE , +.BR FALLOC_FL_ZERO_RANGE +or +.BR FALLOC_FL_INSERT_RANGE , but the file referred to by .I fd is not a regular file. @@ -342,6 +414,8 @@ specifies .BR FALLOC_FL_PUNCH_HOLE or .BR FALLOC_FL_COLLAPSE_RANGE +or +.BR FALLOC_FL_INSERT_RANGE and the file referred to by .I fd @@ -360,7 +434,9 @@ refers to a pipe or FIFO. .B ETXTBSY .I mode specifies -.BR FALLOC_FL_COLLAPSE_RANGE , +.BR FALLOC_FL_COLLAPSE_RANGE +or +.BR FALLOC_FL_INSERT_RANGE , but the file referred to by .IR fd is currently being executed. -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
