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authorNeilBrown <neilb@suse.de>2006-01-08 04:02:39 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-08 23:13:52 -0500
commit4a30131e7dbb17e5fec6958bfac9da9aff1fa29b (patch)
tree2ff6139b393a9a413e2ea4db4dd2d15eec2201f8
parent788540141f4549637e89aadca6e25cf25eb53383 (diff)
[PATCH] Fix some problems with truncate and mtime semantics.
SUS requires that when truncating a file to the size that it currently is: truncate and ftruncate should NOT modify ctime or mtime O_TRUNC SHOULD modify ctime and mtime. Currently mtime and ctime are always modified on most local filesystems (side effect of ->truncate) or never modified (on NFS). With this patch: ATTR_CTIME|ATTR_MTIME are sent with ATTR_SIZE precisely when an update of these times is required whether size changes or not (via a new argument to do_truncate). This allows NFS to do the right thing for O_TRUNC. inode_setattr nolonger forces ATTR_MTIME|ATTR_CTIME when the ATTR_SIZE sets the size to it's current value. This allows local filesystems to do the right thing for f?truncate. Also, the logic in inode_setattr is changed a bit so there are two return points. One returns the error from vmtruncate if it failed, the other returns 0 (there can be no other failure). Finally, if vmtruncate succeeds, and ATTR_SIZE is the only change requested, we now fall-through and mark_inode_dirty. If a filesystem did not have a ->truncate function, then vmtruncate will have changed i_size, without marking the inode as 'dirty', and I think this is wrong. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--fs/attr.c24
-rw-r--r--fs/exec.c2
-rw-r--r--fs/namei.c2
-rw-r--r--fs/open.c9
-rw-r--r--include/linux/fs.h3
5 files changed, 17 insertions, 23 deletions
diff --git a/fs/attr.c b/fs/attr.c
index 67bcd9b14ea5..b34732506f1d 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -67,20 +67,12 @@ EXPORT_SYMBOL(inode_change_ok);
67int inode_setattr(struct inode * inode, struct iattr * attr) 67int inode_setattr(struct inode * inode, struct iattr * attr)
68{ 68{
69 unsigned int ia_valid = attr->ia_valid; 69 unsigned int ia_valid = attr->ia_valid;
70 int error = 0; 70
71 71 if (ia_valid & ATTR_SIZE &&
72 if (ia_valid & ATTR_SIZE) { 72 attr->ia_size != i_size_read(inode)) {
73 if (attr->ia_size != i_size_read(inode)) { 73 int error = vmtruncate(inode, attr->ia_size);
74 error = vmtruncate(inode, attr->ia_size); 74 if (error)
75 if (error || (ia_valid == ATTR_SIZE)) 75 return error;
76 goto out;
77 } else {
78 /*
79 * We skipped the truncate but must still update
80 * timestamps
81 */
82 ia_valid |= ATTR_MTIME|ATTR_CTIME;
83 }
84 } 76 }
85 77
86 if (ia_valid & ATTR_UID) 78 if (ia_valid & ATTR_UID)
@@ -104,8 +96,8 @@ int inode_setattr(struct inode * inode, struct iattr * attr)
104 inode->i_mode = mode; 96 inode->i_mode = mode;
105 } 97 }
106 mark_inode_dirty(inode); 98 mark_inode_dirty(inode);
107out: 99
108 return error; 100 return 0;
109} 101}
110EXPORT_SYMBOL(inode_setattr); 102EXPORT_SYMBOL(inode_setattr);
111 103
diff --git a/fs/exec.c b/fs/exec.c
index e9650cd22a3b..2075b674d85e 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1505,7 +1505,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
1505 goto close_fail; 1505 goto close_fail;
1506 if (!file->f_op->write) 1506 if (!file->f_op->write)
1507 goto close_fail; 1507 goto close_fail;
1508 if (do_truncate(file->f_dentry, 0, file) != 0) 1508 if (do_truncate(file->f_dentry, 0, 0, file) != 0)
1509 goto close_fail; 1509 goto close_fail;
1510 1510
1511 retval = binfmt->core_dump(signr, regs, file); 1511 retval = binfmt->core_dump(signr, regs, file);
diff --git a/fs/namei.c b/fs/namei.c
index 6dbbd42d8b95..300eae088d5f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1491,7 +1491,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
1491 if (!error) { 1491 if (!error) {
1492 DQUOT_INIT(inode); 1492 DQUOT_INIT(inode);
1493 1493
1494 error = do_truncate(dentry, 0, NULL); 1494 error = do_truncate(dentry, 0, ATTR_MTIME|ATTR_CTIME, NULL);
1495 } 1495 }
1496 put_write_access(inode); 1496 put_write_access(inode);
1497 if (error) 1497 if (error)
diff --git a/fs/open.c b/fs/open.c
index f53a5b9ffb7d..94968cb3afca 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -194,7 +194,8 @@ out:
194 return error; 194 return error;
195} 195}
196 196
197int do_truncate(struct dentry *dentry, loff_t length, struct file *filp) 197int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
198 struct file *filp)
198{ 199{
199 int err; 200 int err;
200 struct iattr newattrs; 201 struct iattr newattrs;
@@ -204,7 +205,7 @@ int do_truncate(struct dentry *dentry, loff_t length, struct file *filp)
204 return -EINVAL; 205 return -EINVAL;
205 206
206 newattrs.ia_size = length; 207 newattrs.ia_size = length;
207 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; 208 newattrs.ia_valid = ATTR_SIZE | time_attrs;
208 if (filp) { 209 if (filp) {
209 newattrs.ia_file = filp; 210 newattrs.ia_file = filp;
210 newattrs.ia_valid |= ATTR_FILE; 211 newattrs.ia_valid |= ATTR_FILE;
@@ -266,7 +267,7 @@ static inline long do_sys_truncate(const char __user * path, loff_t length)
266 error = locks_verify_truncate(inode, NULL, length); 267 error = locks_verify_truncate(inode, NULL, length);
267 if (!error) { 268 if (!error) {
268 DQUOT_INIT(inode); 269 DQUOT_INIT(inode);
269 error = do_truncate(nd.dentry, length, NULL); 270 error = do_truncate(nd.dentry, length, 0, NULL);
270 } 271 }
271 put_write_access(inode); 272 put_write_access(inode);
272 273
@@ -318,7 +319,7 @@ static inline long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
318 319
319 error = locks_verify_truncate(inode, file, length); 320 error = locks_verify_truncate(inode, file, length);
320 if (!error) 321 if (!error)
321 error = do_truncate(dentry, length, file); 322 error = do_truncate(dentry, length, 0, file);
322out_putf: 323out_putf:
323 fput(file); 324 fput(file);
324out: 325out:
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ef29500b5df8..74c01aabd4ab 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1344,7 +1344,8 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
1344 1344
1345/* fs/open.c */ 1345/* fs/open.c */
1346 1346
1347extern int do_truncate(struct dentry *, loff_t start, struct file *filp); 1347extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
1348 struct file *filp);
1348extern long do_sys_open(const char __user *filename, int flags, int mode); 1349extern long do_sys_open(const char __user *filename, int flags, int mode);
1349extern struct file *filp_open(const char *, int, int); 1350extern struct file *filp_open(const char *, int, int);
1350extern struct file * dentry_open(struct dentry *, struct vfsmount *, int); 1351extern struct file * dentry_open(struct dentry *, struct vfsmount *, int);