| Message ID | 20220617030345.24712-1-phillip@squashfs.org.uk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Fri, Jun 17, 2022 at 11:04 AM Phillip Lougher <phillip@squashfs.org.uk> wrote: > > This patch adds a function which can be used to read fragments in the > readahead call. > > This function is necessary because filesystems built with the -tailends > (or -always-use-fragments) option may have fragments present which > cannot be currently handled. > > Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> > --- > fs/squashfs/file.c | 35 +++++++++++++++++++++++++++++++++++ > 1 file changed, 35 insertions(+) > > diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c > index f0c64ee272d5..3a4cce16d7da 100644 > --- a/fs/squashfs/file.c > +++ b/fs/squashfs/file.c > @@ -497,6 +497,41 @@ static int squashfs_read_folio(struct file *file, struct folio *folio) > return res; > } > > +static unsigned int squashfs_readahead_fragment(struct page **page, hi Phillip, Since the buffer->error is int, and also the variable to receive the value is res, I modified it when sending it with the series, though it won't affect the result. > + unsigned int pages, unsigned int expected) > +{ > + struct inode *inode = page[0]->mapping->host; > + struct squashfs_cache_entry *buffer = squashfs_get_fragment(inode->i_sb, > + squashfs_i(inode)->fragment_block, > + squashfs_i(inode)->fragment_size); > + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; > + unsigned int n, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; > + > + if (buffer->error) > + goto out; > + > + expected += squashfs_i(inode)->fragment_offset; > + > + for (n = 0; n < pages; n++) { > + unsigned int base = (page[n]->index & mask) << PAGE_SHIFT; > + unsigned int offset = base + squashfs_i(inode)->fragment_offset; > + > + if (expected > offset) { > + unsigned int avail = min_t(unsigned int, expected - > + offset, PAGE_SIZE); > + > + squashfs_fill_page(page[n], buffer, offset, avail); > + } > + > + unlock_page(page[n]); > + put_page(page[n]); > + } > + > +out: > + squashfs_cache_put(buffer); > + return buffer->error; > +} > + > static void squashfs_readahead(struct readahead_control *ractl) > { > struct inode *inode = ractl->mapping->host; > -- > 2.34.1 >
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index f0c64ee272d5..3a4cce16d7da 100644 --- a/fs/squashfs/file.c +++ b/fs/squashfs/file.c @@ -497,6 +497,41 @@ static int squashfs_read_folio(struct file *file, struct folio *folio) return res; } +static unsigned int squashfs_readahead_fragment(struct page **page, + unsigned int pages, unsigned int expected) +{ + struct inode *inode = page[0]->mapping->host; + struct squashfs_cache_entry *buffer = squashfs_get_fragment(inode->i_sb, + squashfs_i(inode)->fragment_block, + squashfs_i(inode)->fragment_size); + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + unsigned int n, mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; + + if (buffer->error) + goto out; + + expected += squashfs_i(inode)->fragment_offset; + + for (n = 0; n < pages; n++) { + unsigned int base = (page[n]->index & mask) << PAGE_SHIFT; + unsigned int offset = base + squashfs_i(inode)->fragment_offset; + + if (expected > offset) { + unsigned int avail = min_t(unsigned int, expected - + offset, PAGE_SIZE); + + squashfs_fill_page(page[n], buffer, offset, avail); + } + + unlock_page(page[n]); + put_page(page[n]); + } + +out: + squashfs_cache_put(buffer); + return buffer->error; +} + static void squashfs_readahead(struct readahead_control *ractl) { struct inode *inode = ractl->mapping->host;
This patch adds a function which can be used to read fragments in the readahead call. This function is necessary because filesystems built with the -tailends (or -always-use-fragments) option may have fragments present which cannot be currently handled. Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> --- fs/squashfs/file.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)