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| author | Sunil Mushran <sunil.mushran@oracle.com> | 2011-07-25 14:58:15 -0700 |
|---|---|---|
| committer | Sunil Mushran <sunil.mushran@oracle.com> | 2011-07-25 14:58:15 -0700 |
| commit | 93862d5e1ab875664c6cc95254fc365028a48bb1 (patch) | |
| tree | 3299a37486b2265e051a4c641aa7cfbb309a69d6 /fs/ocfs2/file.c | |
| parent | 5cffff9e29866a3de98c2c25135b3199491f93b0 (diff) | |
| download | linux-93862d5e1ab875664c6cc95254fc365028a48bb1.tar.gz | |
ocfs2: Implement llseek()
ocfs2 implements its own llseek() to provide the SEEK_HOLE/SEEK_DATA
functionality.
SEEK_HOLE sets the file pointer to the start of either a hole or an unwritten
(preallocated) extent, that is greater than or equal to the supplied offset.
SEEK_DATA sets the file pointer to the start of an allocated extent (not
unwritten) that is greater than or equal to the supplied offset.
If the supplied offset is on a desired region, then the file pointer is set
to it. Offsets greater than or equal to the file size return -ENXIO.
Unwritten (preallocated) extents are considered holes because the file system
treats reads to such regions in the same way as it does to holes.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Diffstat (limited to 'fs/ocfs2/file.c')
| -rw-r--r-- | fs/ocfs2/file.c | 55 |
1 files changed, 53 insertions, 2 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 0fc2bd34039daf..c0f015e11c28f2 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2591,6 +2591,57 @@ bail: return ret; } +/* Refer generic_file_llseek_unlocked() */ +static loff_t ocfs2_file_llseek(struct file *file, loff_t offset, int origin) +{ + struct inode *inode = file->f_mapping->host; + int ret = 0; + + mutex_lock(&inode->i_mutex); + + switch (origin) { + case SEEK_SET: + break; + case SEEK_END: + offset += inode->i_size; + break; + case SEEK_CUR: + if (offset == 0) { + offset = file->f_pos; + goto out; + } + offset += file->f_pos; + break; + case SEEK_DATA: + case SEEK_HOLE: + ret = ocfs2_seek_data_hole_offset(file, &offset, origin); + if (ret) + goto out; + break; + default: + ret = -EINVAL; + goto out; + } + + if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) + ret = -EINVAL; + if (!ret && offset > inode->i_sb->s_maxbytes) + ret = -EINVAL; + if (ret) + goto out; + + if (offset != file->f_pos) { + file->f_pos = offset; + file->f_version = 0; + } + +out: + mutex_unlock(&inode->i_mutex); + if (ret) + return ret; + return offset; +} + const struct inode_operations ocfs2_file_iops = { .setattr = ocfs2_setattr, .getattr = ocfs2_getattr, @@ -2615,7 +2666,7 @@ const struct inode_operations ocfs2_special_file_iops = { * ocfs2_fops_no_plocks and ocfs2_dops_no_plocks! */ const struct file_operations ocfs2_fops = { - .llseek = generic_file_llseek, + .llseek = ocfs2_file_llseek, .read = do_sync_read, .write = do_sync_write, .mmap = ocfs2_mmap, @@ -2663,7 +2714,7 @@ const struct file_operations ocfs2_dops = { * the cluster. */ const struct file_operations ocfs2_fops_no_plocks = { - .llseek = generic_file_llseek, + .llseek = ocfs2_file_llseek, .read = do_sync_read, .write = do_sync_write, .mmap = ocfs2_mmap, |