Messages in this thread Patch in this message |  | | | Date | Thu, 10 Dec 2009 20:25:31 -0800 | | From | Greg KH <> | | Subject | [53/90] ext4: fix ext4_ext_direct_IO()s return value after converting uninit extents |
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2.6.31-stable review patch. If anyone has any objections, please let us know.
------------------ (cherry picked from commit 109f55651954def97fa41ee71c464d268c512ab0) After a direct I/O request covering an uninitalized extent (i.e., created using the fallocate system call) or a hole in a file, ext4 will convert the uninitialized extent so it is marked as initialized by calling ext4_convert_unwritten_extents(). This function returns zero on success.
This return value was getting returned by ext4_direct_IO(); however the file system's direct_IO function is supposed to return the number of bytes read or written on a success. By returning zero, it confused the direct I/O code into falling back to buffered I/O unnecessarily.
Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- fs/ext4/extents.c | 1 + fs/ext4/inode.c | 10 +++++++--- 2 files changed, 8 insertions(+), 3 deletions(-) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3496,6 +3496,7 @@ retry: * * This function is called from the direct IO end io call back * function, to convert the fallocated extents after IO is completed. + * Returns 0 on success. */ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, loff_t len) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3766,13 +3766,17 @@ static ssize_t ext4_ext_direct_IO(int rw if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) { ext4_free_io_end(iocb->private); iocb->private = NULL; - } else if (ret > 0) + } else if (ret > 0) { + int err; /* * for non AIO case, since the IO is already * completed, we could do the convertion right here */ - ret = ext4_convert_unwritten_extents(inode, - offset, ret); + err = ext4_convert_unwritten_extents(inode, + offset, ret); + if (err < 0) + ret = err; + } return ret; }
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