Introduce 'sharecache' mount option to enable page cache sharing in fscache mode.
Signed-off-by: Jingbo Xu <[email protected]> --- Documentation/filesystems/erofs.rst | 2 ++ fs/erofs/inode.c | 4 ++++ fs/erofs/internal.h | 4 ++++ fs/erofs/super.c | 13 +++++++++++++ 4 files changed, 23 insertions(+) diff --git a/Documentation/filesystems/erofs.rst b/Documentation/filesystems/erofs.rst index 958cad2c4997..1fe38323a1bb 100644 --- a/Documentation/filesystems/erofs.rst +++ b/Documentation/filesystems/erofs.rst @@ -123,6 +123,8 @@ fsid=%s Specify a filesystem image ID for Fscache back-end. domain_id=%s Specify a domain ID for Fscache back-end. The blob images are shared among filesystem instances in the same domain. +(no)sharecache Enable page cache sharing among filesystem instances in + the same domain. =================== ========================================================= Sysfs Entries diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index d3b8736fa124..31d3ab8443d1 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -262,6 +262,10 @@ static int erofs_fill_inode(struct inode *inode) inode->i_op = &erofs_generic_iops; if (erofs_inode_is_data_compressed(vi->datalayout)) inode->i_fop = &generic_ro_fops; +#ifdef CONFIG_EROFS_FS_ONDEMAND + else if (erofs_can_share_page(inode)) + inode->i_fop = &erofs_fscache_share_file_fops; +#endif else inode->i_fop = &erofs_file_fops; break; diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index adf6be08b47c..c3ac6d613eb1 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -181,6 +181,7 @@ struct erofs_sb_info { #define EROFS_MOUNT_POSIX_ACL 0x00000020 #define EROFS_MOUNT_DAX_ALWAYS 0x00000040 #define EROFS_MOUNT_DAX_NEVER 0x00000080 +#define EROFS_MOUNT_SHARE_CACHE 0x00000100 #define clear_opt(opt, option) ((opt)->mount_opt &= ~EROFS_MOUNT_##option) #define set_opt(opt, option) ((opt)->mount_opt |= EROFS_MOUNT_##option) @@ -373,6 +374,9 @@ static inline bool erofs_can_share_page(struct inode *inode) struct erofs_inode *vi = EROFS_I(inode); struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); + if (!test_opt(&sbi->opt, SHARE_CACHE)) + return false; + /* enable page cache sharing only in share domain mode */ if (!erofs_is_fscache_mode(inode->i_sb) || !sbi->domain_id) return false; diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 835b69c9511b..d05346d34ed8 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -456,6 +456,7 @@ enum { Opt_device, Opt_fsid, Opt_domain_id, + Opt_sharecache, Opt_err }; @@ -482,6 +483,7 @@ static const struct fs_parameter_spec erofs_fs_parameters[] = { fsparam_string("device", Opt_device), fsparam_string("fsid", Opt_fsid), fsparam_string("domain_id", Opt_domain_id), + fsparam_flag_no("sharecache", Opt_sharecache), {} }; @@ -590,9 +592,16 @@ static int erofs_fc_parse_param(struct fs_context *fc, if (!ctx->domain_id) return -ENOMEM; break; + case Opt_sharecache: + if (result.boolean) + set_opt(&ctx->opt, SHARE_CACHE); + else + clear_opt(&ctx->opt, SHARE_CACHE); + break; #else case Opt_fsid: case Opt_domain_id: + case Opt_sharecache: errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name); break; #endif @@ -1108,6 +1117,10 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root) seq_printf(seq, ",fsid=%s", sbi->fsid); if (sbi->domain_id) seq_printf(seq, ",domain_id=%s", sbi->domain_id); + if (test_opt(opt, SHARE_CACHE)) + seq_puts(seq, ",sharecache"); + else + seq_puts(seq, ",nosharecache"); #endif return 0; } -- 2.19.1.6.gb485710b
