aboutsummaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 10:43:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 10:43:44 -0700
commit105a048a4f35f7a74c7cc20b36dd83658b6ec232 (patch)
tree043b1110cda0042ba35d8aae59382bb094d0af3f /mm
parent00b9b0af5887fed54e899e3b7f5c2ccf5e739def (diff)
parent9aeead73782c4b8e2a91def36dbf95db28605c95 (diff)
downloadlinux-2.6.34-ux500-105a048a4f35f7a74c7cc20b36dd83658b6ec232.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (27 commits) Btrfs: add more error checking to btrfs_dirty_inode Btrfs: allow unaligned DIO Btrfs: drop verbose enospc printk Btrfs: Fix block generation verification race Btrfs: fix preallocation and nodatacow checks in O_DIRECT Btrfs: avoid ENOSPC errors in btrfs_dirty_inode Btrfs: move O_DIRECT space reservation to btrfs_direct_IO Btrfs: rework O_DIRECT enospc handling Btrfs: use async helpers for DIO write checksumming Btrfs: don't walk around with task->state != TASK_RUNNING Btrfs: do aio_write instead of write Btrfs: add basic DIO read/write support direct-io: do not merge logically non-contiguous requests direct-io: add a hook for the fs to provide its own submit_bio function fs: allow short direct-io reads to be completed via buffered IO Btrfs: Metadata ENOSPC handling for balance Btrfs: Pre-allocate space for data relocation Btrfs: Metadata ENOSPC handling for tree log Btrfs: Metadata reservation for orphan inodes Btrfs: Introduce global metadata reservation ...
Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c36
1 files changed, 31 insertions, 5 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 35e12d18656..45a2d18df84 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1275,7 +1275,7 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
{
struct file *filp = iocb->ki_filp;
ssize_t retval;
- unsigned long seg;
+ unsigned long seg = 0;
size_t count;
loff_t *ppos = &iocb->ki_pos;
@@ -1302,21 +1302,47 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
retval = mapping->a_ops->direct_IO(READ, iocb,
iov, pos, nr_segs);
}
- if (retval > 0)
+ if (retval > 0) {
*ppos = pos + retval;
- if (retval) {
+ count -= retval;
+ }
+
+ /*
+ * Btrfs can have a short DIO read if we encounter
+ * compressed extents, so if there was an error, or if
+ * we've already read everything we wanted to, or if
+ * there was a short read because we hit EOF, go ahead
+ * and return. Otherwise fallthrough to buffered io for
+ * the rest of the read.
+ */
+ if (retval < 0 || !count || *ppos >= size) {
file_accessed(filp);
goto out;
}
}
}
+ count = retval;
for (seg = 0; seg < nr_segs; seg++) {
read_descriptor_t desc;
+ loff_t offset = 0;
+
+ /*
+ * If we did a short DIO read we need to skip the section of the
+ * iov that we've already read data into.
+ */
+ if (count) {
+ if (count > iov[seg].iov_len) {
+ count -= iov[seg].iov_len;
+ continue;
+ }
+ offset = count;
+ count = 0;
+ }
desc.written = 0;
- desc.arg.buf = iov[seg].iov_base;
- desc.count = iov[seg].iov_len;
+ desc.arg.buf = iov[seg].iov_base + offset;
+ desc.count = iov[seg].iov_len - offset;
if (desc.count == 0)
continue;
desc.error = 0;