From ec7268ce21b379a248705548573393e4f346b20b Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Mon, 30 Apr 2012 13:14:03 -0500 Subject: [PATCH] ext4: use core vfs llseek code for dir seeks Use the new functionality in generic_file_llseek_size() to accept a custom EOF position, and un-cut-and-paste all the vfs llseek code from ext4. Also fix up comments on ext4_llseek() to reflect reality. Signed-off-by: Eric Sandeen Signed-off-by: Al Viro --- fs/ext4/dir.c | 75 ++++++++++---------------------------------------- fs/ext4/file.c | 6 ++-- 2 files changed, 17 insertions(+), 64 deletions(-) diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index aa39e600d159..8e07d2a5a139 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -324,74 +324,27 @@ static inline loff_t ext4_get_htree_eof(struct file *filp) /* - * ext4_dir_llseek() based on generic_file_llseek() to handle both - * non-htree and htree directories, where the "offset" is in terms - * of the filename hash value instead of the byte offset. + * ext4_dir_llseek() calls generic_file_llseek_size to handle htree + * directories, where the "offset" is in terms of the filename hash + * value instead of the byte offset. * - * NOTE: offsets obtained *before* ext4_set_inode_flag(dir, EXT4_INODE_INDEX) - * will be invalid once the directory was converted into a dx directory + * Because we may return a 64-bit hash that is well beyond offset limits, + * we need to pass the max hash as the maximum allowable offset in + * the htree directory case. + * + * For non-htree, ext4_llseek already chooses the proper max offset. */ loff_t ext4_dir_llseek(struct file *file, loff_t offset, int origin) { struct inode *inode = file->f_mapping->host; - loff_t ret = -EINVAL; int dx_dir = is_dx_dir(inode); + loff_t htree_max = ext4_get_htree_eof(file); - mutex_lock(&inode->i_mutex); - - /* NOTE: relative offsets with dx directories might not work - * as expected, as it is difficult to figure out the - * correct offset between dx hashes */ - - switch (origin) { - case SEEK_END: - if (unlikely(offset > 0)) - goto out_err; /* not supported for directories */ - - /* so only negative offsets are left, does that have a - * meaning for directories at all? */ - if (dx_dir) - offset += ext4_get_htree_eof(file); - else - offset += inode->i_size; - break; - case SEEK_CUR: - /* - * Here we special-case the lseek(fd, 0, SEEK_CUR) - * position-querying operation. Avoid rewriting the "same" - * f_pos value back to the file because a concurrent read(), - * write() or lseek() might have altered it - */ - if (offset == 0) { - offset = file->f_pos; - goto out_ok; - } - - offset += file->f_pos; - break; - } - - if (unlikely(offset < 0)) - goto out_err; - - if (!dx_dir) { - if (offset > inode->i_sb->s_maxbytes) - goto out_err; - } else if (offset > ext4_get_htree_eof(file)) - goto out_err; - - /* Special lock needed here? */ - if (offset != file->f_pos) { - file->f_pos = offset; - file->f_version = 0; - } - -out_ok: - ret = offset; -out_err: - mutex_unlock(&inode->i_mutex); - - return ret; + if (likely(dx_dir)) + return generic_file_llseek_size(file, offset, origin, + htree_max, htree_max); + else + return ext4_llseek(file, offset, origin); } /* diff --git a/fs/ext4/file.c b/fs/ext4/file.c index f3dadd0a0d51..782eecb57e43 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -211,9 +211,9 @@ static int ext4_file_open(struct inode * inode, struct file * filp) } /* - * ext4_llseek() copied from generic_file_llseek() to handle both - * block-mapped and extent-mapped maxbytes values. This should - * otherwise be identical with generic_file_llseek(). + * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values + * by calling generic_file_llseek_size() with the appropriate maxbytes + * value for each. */ loff_t ext4_llseek(struct file *file, loff_t offset, int origin) { -- 2.20.1