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Subject[RFC][PATCH 10/13] make dump_emit() use vfs_write() instead of banging at ->f_op->write directly
From

... and deal with short writes properly - the output might be to pipe, after
all; as it is, e.g. no-MMU case of elf_fdpic coredump can write a whole lot
more than a page worth of data at one call.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/coredump.c | 17 ++++++++++++-----
1 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/fs/coredump.c b/fs/coredump.c
index 319f973..478ebad 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -696,13 +696,20 @@ EXPORT_SYMBOL(dump_write);
int dump_emit(struct coredump_params *cprm, const void *addr, int nr)
{
struct file *file = cprm->file;
- if (dump_interrupted() || !access_ok(VERIFY_READ, addr, nr))
- return 0;
+ loff_t pos = file->f_pos;
+ ssize_t n;
if (cprm->written + nr > cprm->limit)
return 0;
- if (file->f_op->write(file, addr, nr, &file->f_pos) != nr)
- return 0;
- cprm->written += nr;
+ while (nr) {
+ if (dump_interrupted())
+ return 0;
+ n = vfs_write(file, addr, nr, &pos);
+ if (n < 0)
+ return 0;
+ file->f_pos = pos;
+ cprm->written += n;
+ nr -= n;
+ }
return 1;
}
EXPORT_SYMBOL(dump_emit);
--
1.7.2.5



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