diff options
Diffstat (limited to 'fs/squashfs/super.c')
-rw-r--r-- | fs/squashfs/super.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 60d6951915f4..4f74abbc1a54 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -16,6 +16,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/blkdev.h> #include <linux/fs.h> #include <linux/fs_context.h> #include <linux/fs_parser.h> @@ -28,6 +29,7 @@ #include <linux/module.h> #include <linux/magic.h> #include <linux/xattr.h> +#include <linux/backing-dev.h> #include "squashfs_fs.h" #include "squashfs_fs_sb.h" @@ -111,6 +113,24 @@ static const struct squashfs_decompressor *supported_squashfs_filesystem( return decompressor; } +static int squashfs_bdi_init(struct super_block *sb) +{ + int err; + unsigned int major = MAJOR(sb->s_dev); + unsigned int minor = MINOR(sb->s_dev); + + bdi_put(sb->s_bdi); + sb->s_bdi = &noop_backing_dev_info; + + err = super_setup_bdi_name(sb, "squashfs_%u_%u", major, minor); + if (err) + return err; + + sb->s_bdi->ra_pages = 0; + sb->s_bdi->io_pages = 0; + + return 0; +} static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) { @@ -126,6 +146,20 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) TRACE("Entered squashfs_fill_superblock\n"); + /* + * squashfs provides 'backing_dev_info' in order to disable read-ahead. For + * squashfs, I/O is not deferred, it is done immediately in readpage, + * which means the user would always have to wait their own I/O. So the effect + * of readahead is very weak for squashfs. squashfs_bdi_init will set + * sb->s_bdi->ra_pages and sb->s_bdi->io_pages to 0 and close readahead for + * squashfs. + */ + err = squashfs_bdi_init(sb); + if (err) { + errorf(fc, "squashfs init bdi failed"); + return err; + } + sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL); if (sb->s_fs_info == NULL) { ERROR("Failed to allocate squashfs_sb_info\n"); @@ -179,8 +213,8 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) /* Check the filesystem does not extend beyond the end of the block device */ msblk->bytes_used = le64_to_cpu(sblk->bytes_used); - if (msblk->bytes_used < 0 || msblk->bytes_used > - i_size_read(sb->s_bdev->bd_inode)) + if (msblk->bytes_used < 0 || + msblk->bytes_used > bdev_nr_bytes(sb->s_bdev)) goto failed_mount; /* Check block size for sanity */ @@ -550,7 +584,7 @@ static void __exit exit_squashfs_fs(void) static struct inode *squashfs_alloc_inode(struct super_block *sb) { struct squashfs_inode_info *ei = - kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL); + alloc_inode_sb(sb, squashfs_inode_cachep, GFP_KERNEL); return ei ? &ei->vfs_inode : NULL; } |