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| author | Andrew Morton <akpm@osdl.org> | 2006-03-31 02:30:42 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-31 12:18:54 -0800 |
| commit | f79e2abb9bd452d97295f34376dedbec9686b986 (patch) | |
| tree | 56b9998caa11983556e842fb9a8143d86d765fa3 /arch | |
| parent | d6dfd1310d3562698fd7c3c086f6c239f96394ac (diff) | |
| download | linux-f79e2abb9bd452d97295f34376dedbec9686b986.tar.gz linux-f79e2abb9bd452d97295f34376dedbec9686b986.tar.bz2 linux-f79e2abb9bd452d97295f34376dedbec9686b986.zip | |
[PATCH] sys_sync_file_range()
Remove the recently-added LINUX_FADV_ASYNC_WRITE and LINUX_FADV_WRITE_WAIT
fadvise() additions, do it in a new sys_sync_file_range() syscall instead.
Reasons:
- It's more flexible. Things which would require two or three syscalls with
fadvise() can be done in a single syscall.
- Using fadvise() in this manner is something not covered by POSIX.
The patch wires up the syscall for x86.
The sycall is implemented in the new fs/sync.c. The intention is that we can
move sys_fsync(), sys_fdatasync() and perhaps sys_sync() into there later.
Documentation for the syscall is in fs/sync.c.
A test app (sync_file_range.c) is in
http://www.zip.com.au/~akpm/linux/patches/stuff/ext3-tools.tar.gz.
The available-to-GPL-modules do_sync_file_range() is for knfsd: "A COMMIT can
say NFS_DATA_SYNC or NFS_FILE_SYNC. I can skip the ->fsync call for
NFS_DATA_SYNC which is hopefully the more common."
Note: the `async' writeout mode SYNC_FILE_RANGE_WRITE will turn synchronous if
the queue is congested. This is trivial to fix: add a new flag bit, set
wbc->nonblocking. But I'm not sure that we want to expose implementation
details down to that level.
Note: it's notable that we can sync an fd which wasn't opened for writing.
Same with fsync() and fdatasync()).
Note: the code takes some care to handle attempts to sync file contents
outside the 16TB offset on 32-bit machines. It makes such attempts appear to
succeed, for best 32-bit/64-bit compatibility. Perhaps it should make such
requests fail...
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/i386/kernel/syscall_table.S | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S index ce3ef4fa0551..4f58b9c0efe3 100644 --- a/arch/i386/kernel/syscall_table.S +++ b/arch/i386/kernel/syscall_table.S @@ -313,3 +313,4 @@ ENTRY(sys_call_table) .long sys_set_robust_list .long sys_get_robust_list .long sys_splice + .long sys_sync_file_range |