[PATCH 1/2] LSEEK: BTRFS: Avoid i_mutex for SEEK_{CUR,SET,END}
From: Andres Freund <hidden>
Date: 2011-10-01 20:49:34
Also in:
lkml
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
Don't need the i_mutex for those cases, only for SEEK_HOLE/DATA. Really-From: Andi Kleen [off-list ref] Signed-off-by: Andi Kleen <redacted> Signed-off-by: Andres Freund <redacted> --- fs/btrfs/file.c | 27 +++++++++++---------------- 1 files changed, 11 insertions(+), 16 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 7a13337..5bc7116 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c@@ -1809,24 +1809,19 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin) struct inode *inode = file->f_mapping->host; int ret; + if (origin != SEEK_DATA && origin != SEEK_HOLE) + return generic_file_llseek(file, offset, origin); + mutex_lock(&inode->i_mutex); - switch (origin) { - case SEEK_END: - case SEEK_CUR: - offset = generic_file_llseek(file, offset, origin); - goto out; - case SEEK_DATA: - case SEEK_HOLE: - if (offset >= i_size_read(inode)) { - mutex_unlock(&inode->i_mutex); - return -ENXIO; - } + if (offset >= i_size_read(inode)) { + mutex_unlock(&inode->i_mutex); + return -ENXIO; + } - ret = find_desired_extent(inode, &offset, origin); - if (ret) { - mutex_unlock(&inode->i_mutex); - return ret; - } + ret = find_desired_extent(inode, &offset, origin); + if (ret) { + mutex_unlock(&inode->i_mutex); + return ret; } if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
--
1.7.6.409.ge7a85.dirty