| [PATH][RFC] mm: Move common segments checks to separate function [message #9840] |
Wed, 24 January 2007 18:57  |
Dmitriy Monakhov
Messages: 52
Registered: October 2006
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Member |
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Move common segments checks from __generic_file_aio_{read,write}_nolock()
to separate helper function generic_segment_checks().
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
-------
diff --git a/mm/filemap.c b/mm/filemap.c
index 8332c77..d01abb6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1126,6 +1126,38 @@ success:
return size;
}
+/*
+ * Performs necessary segments checks.
+ * Returns bytes count or appropriate error code that caller should return.
+ */
+static ssize_t
+generic_segment_checks(unsigned long nr_segs, const struct iovec *iov,
+ unsigned long access_flag)
+{
+ size_t bcount;
+ unsigned long seg;
+ bcount = 0;
+ for (seg = 0; seg < nr_segs; seg++) {
+ const struct iovec *iv = &iov[seg];
+
+ /*
+ * If any segment has a negative length, or the cumulative
+ * length ever wraps negative then return -EINVAL.
+ */
+ bcount += iv->iov_len;
+ if (unlikely((ssize_t)(bcount|iv->iov_len) < 0))
+ return -EINVAL;
+ if (access_ok(access_flag, iv->iov_base, iv->iov_len))
+ continue;
+ if (seg == 0)
+ return -EFAULT;
+ nr_segs = seg;
+ bcount -= iv->iov_len; /* This segment is no good */
+ break;
+ }
+ return bcount;
+}
+
/**
* generic_file_aio_read - generic filesystem read routine
* @iocb: kernel I/O control block
@@ -1146,25 +1178,7 @@ generic_file_aio_read(struct kiocb *iocb
size_t count;
loff_t *ppos = &iocb->ki_pos;
- count = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- count += iv->iov_len;
- if (unlikely((ssize_t)(count|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- nr_segs = seg;
- count -= iv->iov_len; /* This segment is no good */
- break;
- }
+ count = generic_segment_checks(nr_segs, iov, VERIFY_WRITE);
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (filp->f_flags & O_DIRECT) {
@@ -2225,31 +2239,11 @@ __generic_file_aio_write_nolock(struct k
size_t ocount; /* original count */
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
- unsigned long seg;
loff_t pos;
ssize_t written;
ssize_t err;
- ocount = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- ocount += iv->iov_len;
- if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- nr_segs = seg;
- ocount -= iv->iov_len; /* This segment is no good */
- break;
- }
-
+ ocount = generic_segment_checks(nr_segs, iov, VERIFY_READ);
count = ocount;
pos = *ppos;
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| Re: [PATH][RFC] mm: Move common segments checks to separate function [message #9842 is a reply to message #9840] |
Thu, 25 January 2007 06:49  |
Dmitriy Monakhov
Messages: 52
Registered: October 2006
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Member |
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Dmitriy Monakhov <dmonakhov@openvz.org> writes:
> Move common segments checks from __generic_file_aio_{read,write}_nolock()
> to separate helper function generic_segment_checks().
WOW my eyes ....
I'm realy sorry but this patch is litle bit broken. :(
I've forgot to check generic_segment_checks() return value.
So folowing is the right version:
LOG:
Move common segments checks from __generic_file_aio_{read,write}_nolock()
to separate helper function generic_segment_checks().
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
-------
--- mm/filemap.c.orig 2007-01-25 09:33:03.000000000 +0300
+++ mm/filemap.c 2007-01-25 09:34:25.000000000 +0300
@@ -1126,6 +1126,38 @@ success:
return size;
}
+/*
+ * Performs necessary segments checks.
+ * Returns bytes count or appropriate error code that caller should return.
+ */
+static ssize_t
+generic_segment_checks(unsigned long nr_segs, const struct iovec *iov,
+ unsigned long access_flag)
+{
+ size_t bcount;
+ unsigned long seg;
+ bcount = 0;
+ for (seg = 0; seg < nr_segs; seg++) {
+ const struct iovec *iv = &iov[seg];
+
+ /*
+ * If any segment has a negative length, or the cumulative
+ * length ever wraps negative then return -EINVAL.
+ */
+ bcount += iv->iov_len;
+ if (unlikely((ssize_t)(bcount|iv->iov_len) < 0))
+ return -EINVAL;
+ if (access_ok(access_flag, iv->iov_base, iv->iov_len))
+ continue;
+ if (seg == 0)
+ return -EFAULT;
+ nr_segs = seg;
+ bcount -= iv->iov_len; /* This segment is no good */
+ break;
+ }
+ return bcount;
+}
+
/**
* generic_file_aio_read - generic filesystem read routine
* @iocb: kernel I/O control block
@@ -1146,25 +1178,9 @@ generic_file_aio_read(struct kiocb *iocb
size_t count;
loff_t *ppos = &iocb->ki_pos;
- count = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- count += iv->iov_len;
- if (unlikely((ssize_t)(count|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- nr_segs = seg;
- count -= iv->iov_len; /* This segment is no good */
- break;
- }
+ count = generic_segment_checks(nr_segs, iov, VERIFY_WRITE);
+ if (count < 0)
+ return count;
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (filp->f_flags & O_DIRECT) {
@@ -2225,31 +2241,13 @@ __generic_file_aio_write_nolock(struct k
size_t ocount; /* original count */
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
- unsigned long seg;
loff_t pos;
ssize_t written;
ssize_t err;
- ocount = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- ocount += iv->iov_len;
- if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- nr_segs = seg;
- ocount -= iv->iov_len; /* This segment is no good */
- break;
- }
-
+ ocount = generic_segment_checks(nr_segs, iov, VERIFY_READ);
+ if (ocount < 0)
+ return ocount;
count = ocount;
pos = *ppos;
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