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authorLi Dongyang <[email protected]>2013-06-13 13:51:09 -0400
committerBrian Behlendorf <[email protected]>2013-07-02 09:24:43 -0700
commit802e7b5feb0135483de119eac1da192404eb5bb7 (patch)
tree79e9810d340a3fdc66aa5c557bad3cddb7b72efc /module/zfs/zpl_file.c
parentcf91b2b6b2baaca1e56f23c985e3261cd98bd3f0 (diff)
Add SEEK_DATA/SEEK_HOLE to lseek()/llseek()
The approach taken was the rework zfs_holey() as little as possible and then just wrap the code as needed to ensure correct locking and error handling. Tested with xfstests 285 and 286. All tests pass except for 7-9 of 285 which try to reserve blocks first via fallocate(2) and fail because fallocate(2) is not yet supported. Note that the filp->f_lock spinlock did not exist prior to Linux 2.6.30, but we avoid the need for autotools check by virtue of the fact that SEEK_DATA/SEEK_HOLE support was not added until Linux 3.1. An autoconf check was added for lseek_execute() which is currently a private function but the expectation is that it will be exported perhaps as early as Linux 3.11. Reviewed-by: Richard Laager <[email protected]> Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes #1384
Diffstat (limited to 'module/zfs/zpl_file.c')
-rw-r--r--module/zfs/zpl_file.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/module/zfs/zpl_file.c b/module/zfs/zpl_file.c
index c6d97db50..ebae6bfe2 100644
--- a/module/zfs/zpl_file.c
+++ b/module/zfs/zpl_file.c
@@ -235,6 +235,28 @@ zpl_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
return (wrote);
}
+static loff_t
+zpl_llseek(struct file *filp, loff_t offset, int whence)
+{
+#if defined(SEEK_HOLE) && defined(SEEK_DATA)
+ if (whence == SEEK_DATA || whence == SEEK_HOLE) {
+ struct inode *ip = filp->f_mapping->host;
+ loff_t maxbytes = ip->i_sb->s_maxbytes;
+ loff_t error;
+
+ spl_inode_lock(ip);
+ error = -zfs_holey(ip, whence, &offset);
+ if (error == 0)
+ error = lseek_execute(filp, ip, offset, maxbytes);
+ spl_inode_unlock(ip);
+
+ return (error);
+ }
+#endif /* SEEK_HOLE && SEEK_DATA */
+
+ return generic_file_llseek(filp, offset, whence);
+}
+
/*
* It's worth taking a moment to describe how mmap is implemented
* for zfs because it differs considerably from other Linux filesystems.
@@ -464,7 +486,7 @@ const struct address_space_operations zpl_address_space_operations = {
const struct file_operations zpl_file_operations = {
.open = zpl_open,
.release = zpl_release,
- .llseek = generic_file_llseek,
+ .llseek = zpl_llseek,
.read = zpl_read,
.write = zpl_write,
.mmap = zpl_mmap,