From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Fasheh Subject: [RFC][PATCH 1/2] vfs: allow /proc/pid/maps to return a custom device Date: Fri, 13 May 2011 16:18:48 -0700 Message-ID: <1305328729-9995-2-git-send-email-mfasheh@suse.com> References: <1305328729-9995-1-git-send-email-mfasheh@suse.com> Cc: Chris Mason , linux-fsdevel , Mark Fasheh To: linux-btrfs Return-path: In-Reply-To: <1305328729-9995-1-git-send-email-mfasheh@suse.com> List-ID: This patch introduces a callback in the super_operations structure, 'get_maps_dev' which is then used by procfs to query which device to return for reporting in /proc/[PID]/maps. btrfs wants this so that it can return the same device as it uses from stat(2) calls. Signed-off-by: Mark Fasheh --- fs/proc/task_mmu.c | 2 +- fs/proc/task_nommu.c | 2 +- include/linux/fs.h | 8 ++++++++ 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2e7addf..c0acc19 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -220,7 +220,7 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) if (file) { struct inode *inode = vma->vm_file->f_path.dentry->d_inode; - dev = inode->i_sb->s_dev; + dev = get_maps_dev(inode); ino = inode->i_ino; pgoff = ((loff_t)vma->vm_pgoff) << PAGE_SHIFT; } diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index 980de54..6769efe 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -148,7 +148,7 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) if (file) { struct inode *inode = vma->vm_file->f_path.dentry->d_inode; - dev = inode->i_sb->s_dev; + dev = get_maps_dev(inode); ino = inode->i_ino; pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT; } diff --git a/include/linux/fs.h b/include/linux/fs.h index dbd860a..ad683ad 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1637,8 +1637,16 @@ struct super_operations { ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); #endif int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); + dev_t (*get_maps_dev)(struct inode *); }; +static inline dev_t get_maps_dev(struct inode *inode) +{ + if (inode->i_sb->s_op->get_maps_dev) + return inode->i_sb->s_op->get_maps_dev(inode); + return inode->i_sb->s_dev; +} + /* * Inode state bits. Protected by inode->i_lock * -- 1.6.4.2