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commit f3e87bc838a09163f91ab79696a34f8c19386c55
parent e1626709d6bfcf82dc630e3ae15887e05bb3aa47
Author: kolya <kolya>
Date:   Thu, 16 Oct 2008 15:18:49 +0000

make mkdir crash-safer, as noticed by many students on midterm

Diffstat:
Msysfile.c | 18+++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/sysfile.c b/sysfile.c @@ -237,13 +237,6 @@ create(char *path, int canexist, short type, short major, short minor) ip->minor = minor; ip->nlink = 1; iupdate(ip); - - if(dirlink(dp, name, ip->inum) < 0){ - ip->nlink = 0; - iunlockput(ip); - iunlockput(dp); - return 0; - } if(type == T_DIR){ // Create . and .. entries. dp->nlink++; // for ".." @@ -252,6 +245,17 @@ create(char *path, int canexist, short type, short major, short minor) if(dirlink(ip, ".", ip->inum) < 0 || dirlink(ip, "..", dp->inum) < 0) panic("create dots"); } + + if(dirlink(dp, name, ip->inum) < 0){ + dp->nlink--; + iupdate(dp); + iunlockput(dp); + + ip->nlink = 0; + iunlockput(ip); + return 0; + } + iunlockput(dp); return ip; }