linux/fs/ext4/xattr.c

1585 lines
41 KiB

[PATCH] ext[34]: EA block reference count racing fix There are race issues around ext[34] xattr block release code. ext[34]_xattr_release_block() checks the reference count of xattr block (h_refcount) and frees that xattr block if it is the last one reference it. Unlike ext2, the check of this counter is unprotected by any lock. ext[34]_xattr_release_block() will free the mb_cache entry before freeing that xattr block. There is a small window between the check for the re h_refcount ==1 and the call to mb_cache_entry_free(). During this small window another inode might find this xattr block from the mbcache and reuse it, racing a refcount updates. The xattr block will later be freed by the first inode without notice other inode is still use it. Later if that block is reallocated as a datablock for other file, then more serious problem might happen. We need put a lock around places checking the refount as well to avoid racing issue. Another place need this kind of protection is in ext3_xattr_block_set(), where it will modify the xattr block content in- the-fly if the refcount is 1 (means it's the only inode reference it). This will also fix another issue: the xattr block may not get freed at all if no lock is to protect the refcount check at the release time. It is possible that the last two inodes could release the shared xattr block at the same time. But both of them think they are not the last one so only decreased the h_refcount without freeing xattr block at all. We need to call lock_buffer() after ext3_journal_get_write_access() to avoid deadlock (because the later will call lock_buffer()/unlock_buffer () as well). Signed-off-by: Mingming Cao <cmm@us.ibm.com> Cc: Andreas Gruenbacher <agruen@suse.de> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-28 20:13:35 -08:00
[PATCH] ext[34]: EA block reference count racing fix There are race issues around ext[34] xattr block release code. ext[34]_xattr_release_block() checks the reference count of xattr block (h_refcount) and frees that xattr block if it is the last one reference it. Unlike ext2, the check of this counter is unprotected by any lock. ext[34]_xattr_release_block() will free the mb_cache entry before freeing that xattr block. There is a small window between the check for the re h_refcount ==1 and the call to mb_cache_entry_free(). During this small window another inode might find this xattr block from the mbcache and reuse it, racing a refcount updates. The xattr block will later be freed by the first inode without notice other inode is still use it. Later if that block is reallocated as a datablock for other file, then more serious problem might happen. We need put a lock around places checking the refount as well to avoid racing issue. Another place need this kind of protection is in ext3_xattr_block_set(), where it will modify the xattr block content in- the-fly if the refcount is 1 (means it's the only inode reference it). This will also fix another issue: the xattr block may not get freed at all if no lock is to protect the refcount check at the release time. It is possible that the last two inodes could release the shared xattr block at the same time. But both of them think they are not the last one so only decreased the h_refcount without freeing xattr block at all. We need to call lock_buffer() after ext3_journal_get_write_access() to avoid deadlock (because the later will call lock_buffer()/unlock_buffer () as well). Signed-off-by: Mingming Cao <cmm@us.ibm.com> Cc: Andreas Gruenbacher <agruen@suse.de> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-28 20:13:35 -08:00
[PATCH] ext[34]: EA block reference count racing fix There are race issues around ext[34] xattr block release code. ext[34]_xattr_release_block() checks the reference count of xattr block (h_refcount) and frees that xattr block if it is the last one reference it. Unlike ext2, the check of this counter is unprotected by any lock. ext[34]_xattr_release_block() will free the mb_cache entry before freeing that xattr block. There is a small window between the check for the re h_refcount ==1 and the call to mb_cache_entry_free(). During this small window another inode might find this xattr block from the mbcache and reuse it, racing a refcount updates. The xattr block will later be freed by the first inode without notice other inode is still use it. Later if that block is reallocated as a datablock for other file, then more serious problem might happen. We need put a lock around places checking the refount as well to avoid racing issue. Another place need this kind of protection is in ext3_xattr_block_set(), where it will modify the xattr block content in- the-fly if the refcount is 1 (means it's the only inode reference it). This will also fix another issue: the xattr block may not get freed at all if no lock is to protect the refcount check at the release time. It is possible that the last two inodes could release the shared xattr block at the same time. But both of them think they are not the last one so only decreased the h_refcount without freeing xattr block at all. We need to call lock_buffer() after ext3_journal_get_write_access() to avoid deadlock (because the later will call lock_buffer()/unlock_buffer () as well). Signed-off-by: Mingming Cao <cmm@us.ibm.com> Cc: Andreas Gruenbacher <agruen@suse.de> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-28 20:13:35 -08:00
[PATCH] ext[34]: EA block reference count racing fix There are race issues around ext[34] xattr block release code. ext[34]_xattr_release_block() checks the reference count of xattr block (h_refcount) and frees that xattr block if it is the last one reference it. Unlike ext2, the check of this counter is unprotected by any lock. ext[34]_xattr_release_block() will free the mb_cache entry before freeing that xattr block. There is a small window between the check for the re h_refcount ==1 and the call to mb_cache_entry_free(). During this small window another inode might find this xattr block from the mbcache and reuse it, racing a refcount updates. The xattr block will later be freed by the first inode without notice other inode is still use it. Later if that block is reallocated as a datablock for other file, then more serious problem might happen. We need put a lock around places checking the refount as well to avoid racing issue. Another place need this kind of protection is in ext3_xattr_block_set(), where it will modify the xattr block content in- the-fly if the refcount is 1 (means it's the only inode reference it). This will also fix another issue: the xattr block may not get freed at all if no lock is to protect the refcount check at the release time. It is possible that the last two inodes could release the shared xattr block at the same time. But both of them think they are not the last one so only decreased the h_refcount without freeing xattr block at all. We need to call lock_buffer() after ext3_journal_get_write_access() to avoid deadlock (because the later will call lock_buffer()/unlock_buffer () as well). Signed-off-by: Mingming Cao <cmm@us.ibm.com> Cc: Andreas Gruenbacher <agruen@suse.de> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-28 20:13:35 -08:00
ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields We need to make sure that existing ext3 filesystems can also avail the new fields that have been added to the ext4 inode. We use s_want_extra_isize and s_min_extra_isize to decide by how much we should expand the inode. If EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE feature is set then we expand the inode by max(s_want_extra_isize, s_min_extra_isize , sizeof(ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE) bytes. Actually it is still an open question about whether users should be able to set s_*_extra_isize smaller than the known fields or not. This patch also adds the functionality to expand inodes to include the newly added fields. We start by trying to expand by s_want_extra_isize bytes and if its fails we try to expand by s_min_extra_isize bytes. This is done by changing the i_extra_isize if enough space is available in the inode and no EAs are present. If EAs are present and there is enough space in the inode then the EAs in the inode are shifted to make space. If enough space is not available in the inode due to the EAs then 1 or more EAs are shifted to the external EA block. In the worst case when even the external EA block does not have enough space we inform the user that some EA would need to be deleted or s_min_extra_isize would have to be reduced. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Kalpak Shah <kalpak@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2007-07-18 09:19:57 -04:00
[PATCH] ext[34]: EA block reference count racing fix There are race issues around ext[34] xattr block release code. ext[34]_xattr_release_block() checks the reference count of xattr block (h_refcount) and frees that xattr block if it is the last one reference it. Unlike ext2, the check of this counter is unprotected by any lock. ext[34]_xattr_release_block() will free the mb_cache entry before freeing that xattr block. There is a small window between the check for the re h_refcount ==1 and the call to mb_cache_entry_free(). During this small window another inode might find this xattr block from the mbcache and reuse it, racing a refcount updates. The xattr block will later be freed by the first inode without notice other inode is still use it. Later if that block is reallocated as a datablock for other file, then more serious problem might happen. We need put a lock around places checking the refount as well to avoid racing issue. Another place need this kind of protection is in ext3_xattr_block_set(), where it will modify the xattr block content in- the-fly if the refcount is 1 (means it's the only inode reference it). This will also fix another issue: the xattr block may not get freed at all if no lock is to protect the refcount check at the release time. It is possible that the last two inodes could release the shared xattr block at the same time. But both of them think they are not the last one so only decreased the h_refcount without freeing xattr block at all. We need to call lock_buffer() after ext3_journal_get_write_access() to avoid deadlock (because the later will call lock_buffer()/unlock_buffer () as well). Signed-off-by: Mingming Cao <cmm@us.ibm.com> Cc: Andreas Gruenbacher <agruen@suse.de> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-28 20:13:35 -08:00
[PATCH] ext[34]: EA block reference count racing fix There are race issues around ext[34] xattr block release code. ext[34]_xattr_release_block() checks the reference count of xattr block (h_refcount) and frees that xattr block if it is the last one reference it. Unlike ext2, the check of this counter is unprotected by any lock. ext[34]_xattr_release_block() will free the mb_cache entry before freeing that xattr block. There is a small window between the check for the re h_refcount ==1 and the call to mb_cache_entry_free(). During this small window another inode might find this xattr block from the mbcache and reuse it, racing a refcount updates. The xattr block will later be freed by the first inode without notice other inode is still use it. Later if that block is reallocated as a datablock for other file, then more serious problem might happen. We need put a lock around places checking the refount as well to avoid racing issue. Another place need this kind of protection is in ext3_xattr_block_set(), where it will modify the xattr block content in- the-fly if the refcount is 1 (means it's the only inode reference it). This will also fix another issue: the xattr block may not get freed at all if no lock is to protect the refcount check at the release time. It is possible that the last two inodes could release the shared xattr block at the same time. But both of them think they are not the last one so only decreased the h_refcount without freeing xattr block at all. We need to call lock_buffer() after ext3_journal_get_write_access() to avoid deadlock (because the later will call lock_buffer()/unlock_buffer () as well). Signed-off-by: Mingming Cao <cmm@us.ibm.com> Cc: Andreas Gruenbacher <agruen@suse.de> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-28 20:13:35 -08:00
[PATCH] ext[34]: EA block reference count racing fix There are race issues around ext[34] xattr block release code. ext[34]_xattr_release_block() checks the reference count of xattr block (h_refcount) and frees that xattr block if it is the last one reference it. Unlike ext2, the check of this counter is unprotected by any lock. ext[34]_xattr_release_block() will free the mb_cache entry before freeing that xattr block. There is a small window between the check for the re h_refcount ==1 and the call to mb_cache_entry_free(). During this small window another inode might find this xattr block from the mbcache and reuse it, racing a refcount updates. The xattr block will later be freed by the first inode without notice other inode is still use it. Later if that block is reallocated as a datablock for other file, then more serious problem might happen. We need put a lock around places checking the refount as well to avoid racing issue. Another place need this kind of protection is in ext3_xattr_block_set(), where it will modify the xattr block content in- the-fly if the refcount is 1 (means it's the only inode reference it). This will also fix another issue: the xattr block may not get freed at all if no lock is to protect the refcount check at the release time. It is possible that the last two inodes could release the shared xattr block at the same time. But both of them think they are not the last one so only decreased the h_refcount without freeing xattr block at all. We need to call lock_buffer() after ext3_journal_get_write_access() to avoid deadlock (because the later will call lock_buffer()/unlock_buffer () as well). Signed-off-by: Mingming Cao <cmm@us.ibm.com> Cc: Andreas Gruenbacher <agruen@suse.de> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-28 20:13:35 -08:00
ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields We need to make sure that existing ext3 filesystems can also avail the new fields that have been added to the ext4 inode. We use s_want_extra_isize and s_min_extra_isize to decide by how much we should expand the inode. If EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE feature is set then we expand the inode by max(s_want_extra_isize, s_min_extra_isize , sizeof(ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE) bytes. Actually it is still an open question about whether users should be able to set s_*_extra_isize smaller than the known fields or not. This patch also adds the functionality to expand inodes to include the newly added fields. We start by trying to expand by s_want_extra_isize bytes and if its fails we try to expand by s_min_extra_isize bytes. This is done by changing the i_extra_isize if enough space is available in the inode and no EAs are present. If EAs are present and there is enough space in the inode then the EAs in the inode are shifted to make space. If enough space is not available in the inode due to the EAs then 1 or more EAs are shifted to the external EA block. In the worst case when even the external EA block does not have enough space we inform the user that some EA would need to be deleted or s_min_extra_isize would have to be reduced. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Kalpak Shah <kalpak@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2007-07-18 09:19:57 -04:00
ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields We need to make sure that existing ext3 filesystems can also avail the new fields that have been added to the ext4 inode. We use s_want_extra_isize and s_min_extra_isize to decide by how much we should expand the inode. If EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE feature is set then we expand the inode by max(s_want_extra_isize, s_min_extra_isize , sizeof(ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE) bytes. Actually it is still an open question about whether users should be able to set s_*_extra_isize smaller than the known fields or not. This patch also adds the functionality to expand inodes to include the newly added fields. We start by trying to expand by s_want_extra_isize bytes and if its fails we try to expand by s_min_extra_isize bytes. This is done by changing the i_extra_isize if enough space is available in the inode and no EAs are present. If EAs are present and there is enough space in the inode then the EAs in the inode are shifted to make space. If enough space is not available in the inode due to the EAs then 1 or more EAs are shifted to the external EA block. In the worst case when even the external EA block does not have enough space we inform the user that some EA would need to be deleted or s_min_extra_isize would have to be reduced. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Kalpak Shah <kalpak@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2007-07-18 09:19:57 -04:00
ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields We need to make sure that existing ext3 filesystems can also avail the new fields that have been added to the ext4 inode. We use s_want_extra_isize and s_min_extra_isize to decide by how much we should expand the inode. If EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE feature is set then we expand the inode by max(s_want_extra_isize, s_min_extra_isize , sizeof(ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE) bytes. Actually it is still an open question about whether users should be able to set s_*_extra_isize smaller than the known fields or not. This patch also adds the functionality to expand inodes to include the newly added fields. We start by trying to expand by s_want_extra_isize bytes and if its fails we try to expand by s_min_extra_isize bytes. This is done by changing the i_extra_isize if enough space is available in the inode and no EAs are present. If EAs are present and there is enough space in the inode then the EAs in the inode are shifted to make space. If enough space is not available in the inode due to the EAs then 1 or more EAs are shifted to the external EA block. In the worst case when even the external EA block does not have enough space we inform the user that some EA would need to be deleted or s_min_extra_isize would have to be reduced. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Kalpak Shah <kalpak@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2007-07-18 09:19:57 -04:00
ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields We need to make sure that existing ext3 filesystems can also avail the new fields that have been added to the ext4 inode. We use s_want_extra_isize and s_min_extra_isize to decide by how much we should expand the inode. If EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE feature is set then we expand the inode by max(s_want_extra_isize, s_min_extra_isize , sizeof(ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE) bytes. Actually it is still an open question about whether users should be able to set s_*_extra_isize smaller than the known fields or not. This patch also adds the functionality to expand inodes to include the newly added fields. We start by trying to expand by s_want_extra_isize bytes and if its fails we try to expand by s_min_extra_isize bytes. This is done by changing the i_extra_isize if enough space is available in the inode and no EAs are present. If EAs are present and there is enough space in the inode then the EAs in the inode are shifted to make space. If enough space is not available in the inode due to the EAs then 1 or more EAs are shifted to the external EA block. In the worst case when even the external EA block does not have enough space we inform the user that some EA would need to be deleted or s_min_extra_isize would have to be reduced. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Kalpak Shah <kalpak@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2007-07-18 09:19:57 -04:00
ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields We need to make sure that existing ext3 filesystems can also avail the new fields that have been added to the ext4 inode. We use s_want_extra_isize and s_min_extra_isize to decide by how much we should expand the inode. If EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE feature is set then we expand the inode by max(s_want_extra_isize, s_min_extra_isize , sizeof(ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE) bytes. Actually it is still an open question about whether users should be able to set s_*_extra_isize smaller than the known fields or not. This patch also adds the functionality to expand inodes to include the newly added fields. We start by trying to expand by s_want_extra_isize bytes and if its fails we try to expand by s_min_extra_isize bytes. This is done by changing the i_extra_isize if enough space is available in the inode and no EAs are present. If EAs are present and there is enough space in the inode then the EAs in the inode are shifted to make space. If enough space is not available in the inode due to the EAs then 1 or more EAs are shifted to the external EA block. In the worst case when even the external EA block does not have enough space we inform the user that some EA would need to be deleted or s_min_extra_isize would have to be reduced. Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Kalpak Shah <kalpak@clusterfs.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2007-07-18 09:19:57 -04:00