diff options
| author | Hugh Dickins | 2008-07-23 21:27:35 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2008-07-24 10:47:16 -0700 |
| commit | bcd78e49613c41b5bed96fa288e983876f286a59 (patch) | |
| tree | 0ad2591ca2e0d46923d8ec489ef7378f1a3c0d8e /mm/shmem.c | |
| parent | 11fa977ecde652ab324dd79c179deb52e82a8df1 (diff) | |
tmpfs: support aio
We have a request for tmpfs to support the AIO interface: easily done, no
more than replacing the old shmem_file_read by shmem_file_aio_read,
cribbed from generic_file_aio_read. (In 2.6.25 its write side was already
changed to use generic_file_aio_write.)
Incorporate cleanups from Andrew Morton and Harvey Harrison.
Tests out fine with LTP's ltp-aiodio.sh, given hacks (not included) to
support O_DIRECT. tmpfs cannot honestly support O_DIRECT: its
cache-avoiding-IO nature is at odds with direct IO-avoiding-cache.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Tested-by: Lawrence Greenfield <leg@google.com>
Cc: Christoph Rohland <hans-christoph.rohland@sap.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 55 |
1 files changed, 34 insertions, 21 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index e2a6ae1a44e9..9ffbea9b79e1 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1690,26 +1690,38 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_ file_accessed(filp); } -static ssize_t shmem_file_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) -{ - read_descriptor_t desc; - - if ((ssize_t) count < 0) - return -EINVAL; - if (!access_ok(VERIFY_WRITE, buf, count)) - return -EFAULT; - if (!count) - return 0; - - desc.written = 0; - desc.count = count; - desc.arg.buf = buf; - desc.error = 0; - - do_shmem_file_read(filp, ppos, &desc, file_read_actor); - if (desc.written) - return desc.written; - return desc.error; +static ssize_t shmem_file_aio_read(struct kiocb *iocb, + const struct iovec *iov, unsigned long nr_segs, loff_t pos) +{ + struct file *filp = iocb->ki_filp; + ssize_t retval; + unsigned long seg; + size_t count; + loff_t *ppos = &iocb->ki_pos; + + retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); + if (retval) + return retval; + + for (seg = 0; seg < nr_segs; seg++) { + read_descriptor_t desc; + + desc.written = 0; + desc.arg.buf = iov[seg].iov_base; + desc.count = iov[seg].iov_len; + if (desc.count == 0) + continue; + desc.error = 0; + do_shmem_file_read(filp, ppos, &desc, file_read_actor); + retval += desc.written; + if (desc.error) { + retval = retval ?: desc.error; + break; + } + if (desc.count > 0) + break; + } + return retval; } static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) @@ -2369,8 +2381,9 @@ static const struct file_operations shmem_file_operations = { .mmap = shmem_mmap, #ifdef CONFIG_TMPFS .llseek = generic_file_llseek, - .read = shmem_file_read, + .read = do_sync_read, .write = do_sync_write, + .aio_read = shmem_file_aio_read, .aio_write = generic_file_aio_write, .fsync = simple_sync_file, .splice_read = generic_file_splice_read, |