From 9a53c3a783c2fa9b969628e65695c11c3e51e673 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 30 Sep 2006 23:29:03 -0700 Subject: [PATCH] r/o bind mounts: unlink: monitor i_nlink When a filesystem decrements i_nlink to zero, it means that a write must be performed in order to drop the inode from the filesystem. We're shortly going to have keep filesystems from being remounted r/o between the time that this i_nlink decrement and that write occurs. So, add a little helper function to do the decrements. We'll tie into it in a bit to note when i_nlink hits zero. Signed-off-by: Dave Hansen Acked-by: Christoph Hellwig Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/vfat/namei.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'fs/vfat/namei.c') diff --git a/fs/vfat/namei.c b/fs/vfat/namei.c index 9a8f48bae95..090d74ffa06 100644 --- a/fs/vfat/namei.c +++ b/fs/vfat/namei.c @@ -782,7 +782,7 @@ static int vfat_rmdir(struct inode *dir, struct dentry *dentry) err = fat_remove_entries(dir, &sinfo); /* and releases bh */ if (err) goto out; - dir->i_nlink--; + drop_nlink(dir); inode->i_nlink = 0; inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; @@ -930,7 +930,7 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, if (err) goto error_dotdot; } - old_dir->i_nlink--; + drop_nlink(old_dir); if (!new_inode) new_dir->i_nlink++; } @@ -947,10 +947,9 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, mark_inode_dirty(old_dir); if (new_inode) { + drop_nlink(new_inode); if (is_dir) - new_inode->i_nlink -= 2; - else - new_inode->i_nlink--; + drop_nlink(new_inode); new_inode->i_ctime = ts; } out: -- cgit v1.2.3 From d8c76e6f45c111c32a4b3e50a2adc9210737b0d8 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 30 Sep 2006 23:29:04 -0700 Subject: [PATCH] r/o bind mount prepwork: inc_nlink() helper This is mostly included for parity with dec_nlink(), where we will have some more hooks. This one should stay pretty darn straightforward for now. Signed-off-by: Dave Hansen Acked-by: Christoph Hellwig Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/vfat/namei.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/vfat/namei.c') diff --git a/fs/vfat/namei.c b/fs/vfat/namei.c index 090d74ffa06..5846ba2d5d9 100644 --- a/fs/vfat/namei.c +++ b/fs/vfat/namei.c @@ -837,7 +837,7 @@ static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode) if (err) goto out_free; dir->i_version++; - dir->i_nlink++; + inc_nlink(dir); inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); brelse(sinfo.bh); @@ -932,7 +932,7 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, } drop_nlink(old_dir); if (!new_inode) - new_dir->i_nlink++; + inc_nlink(new_dir); } err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ -- cgit v1.2.3 From ce71ec36840368b877fb63bd14c8e67ab62d08b1 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 30 Sep 2006 23:29:06 -0700 Subject: [PATCH] r/o bind mounts: monitor zeroing of i_nlink Some filesystems, instead of simply decrementing i_nlink, simply zero it during an unlink operation. We need to catch these in addition to the decrement operations. Signed-off-by: Dave Hansen Acked-by: Christoph Hellwig Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/vfat/namei.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/vfat/namei.c') diff --git a/fs/vfat/namei.c b/fs/vfat/namei.c index 5846ba2d5d9..edb711ff7b0 100644 --- a/fs/vfat/namei.c +++ b/fs/vfat/namei.c @@ -784,7 +784,7 @@ static int vfat_rmdir(struct inode *dir, struct dentry *dentry) goto out; drop_nlink(dir); - inode->i_nlink = 0; + clear_nlink(inode); inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; fat_detach(inode); out: @@ -808,7 +808,7 @@ static int vfat_unlink(struct inode *dir, struct dentry *dentry) err = fat_remove_entries(dir, &sinfo); /* and releases bh */ if (err) goto out; - inode->i_nlink = 0; + clear_nlink(inode); inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; fat_detach(inode); out: -- cgit v1.2.3